PHYSICS HONOURS 2009

UNIVERSITY OF SYDNEY
Honours Webpage:
http://www.physics.usyd.edu.au/current/hons.shtml
Honours Co-ordinator:
Dr Stephen Bartlett
Room 317
School of Physics
University of Sydney, NSW 2006
Telephone: (02) 9351 3169
Facsimile: (02) 9351 7726
Email: 4thyear director@physics.usyd.edu.au
(Version: v.2, 11 September 2008)
Contents

1 General Information 3
1.1 Why do Honours in Physics? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 Requirements for Entry to Honours Year . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.3 Syllabus for Physics Honours 2009 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.4 Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.5 Enrolment, Scholarships, and Financial Assistance . . . . . . . . . . . . . . . . . . . . . . 4
1.6 What if you have a Problem? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2 Important Dates 5
3 Lecture Courses 6
4 Research Project 8
4.1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.2 Report Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.2.1 Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.2.2 Presentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.2.3 Deadlines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4.3 Assessment of Honours Projects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4.3.1 Criteria for Talk Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4.3.2 Criteria for Thesis Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

5 Projects available in 2009 12
5.1 Overview of Research Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.2 Projects for 2009 by research area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

1 General Information

To obtain Honours in Physics it is necessary to complete a fourth undergraduate year which is devoted to the study of Physics. Students may also undertake the Honours course part-time over two years (in which case the research project must be completed in two consecutive semesters), and/or start mid-year. Upon completion, a student is eligible for the award of First Class Honours, Second Class Honours (Division 1 or 2) or Third Class Honours. University Medals in Physics are awarded to the top students for outstanding achievement. The same program is taken by candidates for the Graduate Diploma in Science (Physics).

1.1 Why do Honours in Physics?

If you are interested in a research career in physics, an Honours degree is realistically the minimum requirement, although a Pass degree will prepare you for many careers in physics and related areas. It is also necessary to have an Honours degree before proceeding to postgraduate study. By doing Honours you gain not only the benefit of studying physics to a higher level (with a wide choice of courses to be taken), but you also gain invaluable experience in undertaking a research project supervised by one or more members of staff, and producing a Report. Many students also end up publishing one or more scientific papers based on their Honours research.

The School offers a lively academic environment, with roughly 28 academic staff, 6 Federation Fellows, more than 80 Research Fellows and Associates, and over 100 Postgraduate Research Students. Honours classes have recently had more than 25 students enrolled, enabling stimulating interaction between students. There is also a diverse range of postgraduate opportunities for those who wish to continue their studies.

During the Honours year you will be welcomed as a member of the active research group in which you undertake your project. You will be provided with office accommodation and access to the School’s extensive computer facilities plus sophisticated software and (where relevant) laboratory and astronomical equipment. Employment for 1st Year teaching of a few hours per week may be available (information from the Student Support Office in the School of Physics).

1.2 Requirements for Entry to Honours Year
To be eligible to enrol in Physics Honours students shall satisfy all of the following:
(a) have qualified for the award of a pass degree; or be a pass graduate of the Faculty of Science; or be a pass graduate holding a Bachelor of Science degree (or equivalent) from another institution;
(b) have a grade average of at least 65, averaged across at least 48 credit points of undergraduate units of study. These 48 credit points should not include Junior Units where the degree is available on a full time basis to high school graduates;
(c) have met the Science Weighted Average Mark (SCIWAM) requirement of at least 65; (d) have a pass average in 24 units of Senior Physics (or equivalent at another institution).
In special circumstances, students not satisfying these requirements may be permitted to enrol, including those who have obtained good results in related disciplines (e.g., Mathematics, Chemistry) in 3rd Year. Students not satisfying these requirements may also be eligible to undertake the Physics Honours course as a candidate for the Graduate Diploma in Science (Physics). Students from other universities are eligible to enrol in Honours if their results are of equivalent standard.

Students intending to undertake a primarily theoretical project in Physics Honours are advised to take a substantial number of Mathematics options in their Senior Year. Suggested options can be found in the Senior Physics Handbook & webpage. All students are urged to take 36–48 credit points of Senior level courses (including at least 24 of Physics) prior to starting Honours. Such courses, in whatever subject area, provide far better preparation for Honours study than equivalent credit points at more junior levels.

1.3 Syllabus for Physics Honours 2009

• Six lecture courses (or equivalent) chosen from the list given in the section “Lecture Courses.”
• A research project in physics. These projects involve computational, experimental, observational, and/or A research project in physics. These projects involve computational, experimental, observational, and/or words) report. The projects are supervised within the research groups of the School of Physics, although these groupings are flexible and students may often have projects will span interests in more than one research area. A more detailed listing of research areas and specific topics is given in the section “Research Projects”.

• With approval from the Honours Coordinator, projects may be jointly supervised by researchers from groups outside the School of Physics, including other University Departments, the CSIRO, the Electron Microscope Unit, the Centre for Ultrahigh bandwidth Devices for Optical Systems (CUDOS) or a teaching hospital such as Westmead or Royal Prince Alfred.

• At the beginning of the March Semester there is a program to introduce students to their Honours year, including a compulsory instructional course on Safety and Rescuscitation and a library information session on database management and bibliography tools. All Honours students are expected to attend School of Physics Colloquia which are usually held on Mondays, at 3:15 pm. The colloquium noticeboard is outside the Physics Tea Room.

1.4 Assessment

Half of the total marks available are allocated to coursework and half to the research project. The mark for the research project is obtained by combining the mark given by the student’s own research group (weighting 60% for the project work and 10% for a talk on the project) and a mark based on the report only (weighting 30%) assessed by examiners from other research areas in the School of Physics. A more detailed description of the project requirements is given in the section “Assessment for Research Projects”.
The method of assessment for lecture courses is at the lecturer’s discretion.
On average, students’ Honours grades in the Faculty of Science are about 10 marks higher than their WAMs. Therefore, on average, a student with a WAM of 70+ will achieve First Class Honours. For a WAM in the range 65–70, a grade of Honours H2.1 is likely, and for a WAM in the range 60–65 a likely grade is H2.2. However, these grades should not be seen as guarantees, strict predictors or a limitation for any individual student. Your Honours mark is entirely determined by your performance according to the assessment criteria outlined in this handbook.

Honours students graduating with an exceptionally high mark (typically > 95%) may receive a University Medal. The award of University Medals is subject to the following Faculty rule: awardees must have a WAM for 2nd and 3rd Year (weighted in the ratio 2:3) of at least 80, although students with WAMs of 77–79 may be eligible for a Medal if it can be demonstrated that their results have been adversely affected by circumstances beyond their control (e.g., sickness, accident).

1.5 Enrolment, Scholarships, and Financial Assistance

Please contact prospective supervisors as early as possible to discuss the project. Students are free to choose their projects and supervisors, subject to availability. Outlines are given in the Research Projects section of the Honours Handbook.
However, you must still enrol via the University’s formal enrolment channels. Further information on enrolment procedures can be obtained by contacting the Faculty of Science office.
The Units of Study for Physics Honours are PHYS 4011, PHYS 4012, PHYS 4013 and PHYS 4014. Each are for 12 Credit Points and you need to enrol in two per Semester if you are a full-time student or one if you are enrolled part-time. It is not critically important in which order you choose these units as long as you complete all four by the end of your Honours degree. Our Honours Program of courses and project cannot be mapped exactly onto these Units. In addition, if you choose a Senior Physics option or a course from another Department, you do not need to enrol separately for that subject. The assessments are handled internally. Enrolment in Honours Units of Study satisfies the Faculty and University requirements.

The School of Physics and the University of Sydney offers a number of scholarships and other forms of financial assistance for students undertaking Honours. Details specific to Honours Physics can be found on the ‘Honours Scholarships’ webpage, accessible through the Honours webpage. Further details can be obtained by consulting the Faculty of Science Handbook, the office of the Faculty of Science, the Research and Scholarships office, or the Student Centre.

1.6 What if you have a Problem?

If any problems arise that impede your progress, the University has procedures to ensure that you are not disadvantaged. You should see the Honours Coordinator and/or one of the University student assistance services as soon as difficulties arise. Please don’t try to “tough it out” or just drop out — issues can usually be resolved to allow you to complete Honours without harming your results.

For medical conditions that cause your performance to be impaired, or force you to miss time, you should obtain a medical certificate immediately (legally, they can’t be given retroactively) to be submitted with a Special Consideration form to the Student Support Office in the School of Physics. Personal/family difficulties that affect your performance are also grounds for Special Consideration and you may wish to consult the Student Counselling Service to determine the best course of action. Student Services (in the Education Building) can also assist you with financial, accommodation, learning, disability, international-student, and other issues that might arise.

2 Important Dates

All dates are referred to the start dates of the standard undergraduate semesters the next four of which are 2 March 2009, 27 July 2009, 1 March 2010 and 26 July 2010. Submissions given as being due at the end of a given week, must be handed in by noon on the Friday of that week.

March 2009 (First Semester) Commencement

TASK
Start research work
Honours Induction
Lectures begin
Submit research plan
Semester 1 exams start
Lectures begin
Submit draft literature survey If revised, submit new plan Draft report to Supervisor Submit Research report Semester 2 exams start
DATES and DEADLINES
3 weeks before Semester 1 begins (9 February) Monday 23 February
Monday 2 March (week 1)
Friday 13 March (end of week 2)
Tuesday 9 June (stu-vac, week 14)
Monday 27 July (week 1)
Friday 7 August (end of week 2)
Friday 7 August (end of week 2)
Recommended: Friday 18 September (end of week 8) Friday 23 October (end of week 12)
Monday 2 November (stu-vac, week 14)

July 2009 (Second Semester) Commencement

TASK
Start research work
Mid-year Induction
Lectures begin
Submit research plan
Semester 2 exams start
Stop research work
Restart research work
Lectures begin
Submit draft literature survey If revised, submit new plan Draft report to Supervisor Submit Research report Semester 1 exams start
DATES and DEADLINES
3 weeks before Semester 2 begins (6 July)
Monday 20 July
Monday 27 July (week 1)
Friday 7 August (end of week 2)
Monday 2 November (stu-vac, week 14)
mid-December
3 weeks before Semester 1, 2010 begins (8 February) Monday 1 March (week 1)
Friday 12 March (end of week 2)
Friday 12 March (end of week 2)
Recommended: Friday 30 April (end of week 8) Friday 28 May (end of week 12)
Tuesday 8 June (stu-vac, week 14)
The Physics Honours Noticeboard is in the Physics Tea Room (Room 319)
3 Lecture Courses

• Physics Honours students must complete six full-courses from those listed below, subject to the constraints indicated. A list of courses chosen for the year must be submitted to the Honours Coordinator within two weeks of the start of lectures, on the form provided at the Honours Induction Day.

• A full-course is typically 20 lectures. Half-courses will be 10 lectures in length. Courses co-offered with the Masters programs are credited as 1.5 Honours courses; the number of lectures may vary. It is up to you how you arrange your six courses. It is advised, however, that you take a heavier load in your first semester, so that you have more time to devote to your project in the second semester. Recommended options are: 4 courses in first Semester and 2 in second, 3^1 in the first Semester and 2^1 in the second2 2 Semester, or 3 courses in each semester. You should consult with your supervisor to gauge how your research project load is distributed.

• Written examinations scheduled for courses, both full and half length, will be held as usual at the end of Semester (see Important Dates Section), typically in Week 14 (Stuvac) and Week 15. However, midsemester tests may be held as part of the assessment for courses, to assist students with gauging their progress.

• A proposed two year Program of Courses is given below, particularly to aid mid-year intake and part-time students who will continue with their candidature into 2010. It is possible there will be minor amendments to the list of courses.

• Timetables and Course Outlines will be posted on the webpage prior to the start of each Semester. Schedules are set to avoid clashes with Senior Physics options and Mathematics Honours courses, where possible.

Provisional two year Program of Courses Semester 1, 2009 Semester 2, 2009 AQM GR AET PSM AOP ND SM (0.5) PA LTP (0.5) ACM (0.5) TLP (0.5) BR (0.5) NP (1.5) Semester 1, 2010 Semester 2, 2010 AQM GR AET RQT SM (0.5) SP LTP (0.5) ND NP (1.5) ACM (0.5) RP&D (1.5) other (0.5) other optics RP&D (1.5)
Course names

Full courses
AET – Advanced Electromagnetic Theory AQM – Advanced Quantum Mechanics AOP – Advanced Optical Physics GR – General Relativity
PSM – Physics of the Standard Model RQT – Relativistic Quantum Theory SP – Space Physics
PA – Plasma Astrophysics
ND – Neurodynamics
Half courses
SM – Statistical Mechanics
LTP – Low Temperature Physics
IBP – Industry, Business and Physics KT – Kinetic Theory
MSP – Modern Semiconductor Physics POP – Practice of Physics
TLP – Teaching and Learning Physics BR – Bayesian Reasoning
ACM – Advanced Condensed Matter Physics

Courses co-offered with Masters (One-and-a-half courses)
NP – Nuclear Physics (co-offered with Masters in Applied Nuclear Science) RP&D – Radiation Physics and Dosimetry (co-offered with Masters in Medical Physics)

Other Course Possibilities
1. Senior Physics Options

Students may choose one or possibly two Senior Physics lecture courses (not previously taken). Any Senior Physics option chosen must be taken at the Advanced level. Students who have come from another University must consult the Honours Coordinator regarding their choices.

The list of options available is on the website http://www.physics.usyd.edu.au/student.html at the link for Senior Physics. Each Senior Physics lecture module (e.g., Thermodynamics) is credited as a half-course towards your Honours requirements.
The senior COSC course is 6 Credit Points. Typically, Honours students take this course as a full course and are given a modified assessment.
2. Coursework Masters Courses

The School of Physics offers several postgraduate coursework degrees. Two Honours courses (Nuclear Physics, and Radiation Physics and Dosimetry) are co-offered with these Masters courses; such courses are considered to be Physics Honours courses and are not subject to any limitations on number. Honours students may, with permission from the Honours Coordinator, take additional courses offered in the Masters program if appropriate. For more information students should contact the relevant Postgraduate Coursework Coordinator.

3. Courses in other Disciplines

As long as students take at least 4 out of their 6 courses within the School of Physics, they may take courses offered by other departments, with the approval of the Physics Honours Coordinator. In the past approved courses have been taken from Departments including Chemistry, Engineering, History & Philosophy of Science, Biochemistry and Education.

In particular, students may include courses from Honours or Senior Level (Advanced) from the Department of Mathematics & Statistics, subject to the same limitations for Physics and Senior level courses given above, and with the approval of the Honours Coordinator. You should be aware that all Senior Mathematics Units of Study are worth 6 Credit Points (and count for 1.5 courses in your Honours Program). Honours Mathematics courses are equivalent to either 4 or 6 Credit Points; please discuss any such course you may take with the Honours Co-ordinator, so that you are credited appropriately.

4 Research Project
4.1 General Information

Progress and outcomes in your project will be assessed by a variety of means, some of which are designed to ensure that your work proceeds smoothly, others which carry a mark value. The research component of the Physics Honours program counts 50% of the final mark. The sub-division of this assessment is given below.

• At the start of the project you and your supervisor will write a one-page maximum Research Plan, including a list of equipment/data/programs needed, a proposed plan of expected progress, and a statement certifying the supervisor’s availability and the feasibility of the project. This will be submitted to the Honours Coordinator.

• A draft Introduction and Literature Review (see below) will be due two weeks after the start of the 2nd Semester of your project, with a copy going to the Honours Coordinator, along with a revised Research Plan (if appropriate).
• A 20–30 minute talk on your project will be given to your research group near the end of your project work. ASSESSMENT: 10%.
• A draft Report should be submitted to your supervisor approximately one month before the final version is due.
• The finished Report will be submitted at the end of week 12 of the second semester of your Project. ASSESSMENT: 60% from research group, 30% from external examiners in the School of Physics.
4.2 Report Requirements

Students write an Honours research project Report. It should be written so that it can be understood by a physicist who is not a specialist in the subject. Such a person should be able to acquire a good understanding of the subject from your Report. As the ability to write clearly is an important skill for a scientist, it is desirable that you devote considerable effort to the clarity of your expression and to the organization of your Report. Hence, you must not wait until the second half of your second semester to start thinking about it.
Guidelines for preparation are provided below. Reports that do not comply with these Guidelines will be returned for re-writing.
4.2.1 Format
More detailed explanations are given below, but the layout of your Report (giving maximum number of pages allowed) should be as follows:
SECTION OF REPORT
Title Page
Abstract
Statement of Originality
Acknowledgements
Statement of Contribution of Student Table of Contents
Introduction & Survey of Literature Main body of Report
References
Appendices
PAGE NUMBER & COMMENTS
Page 1 (use Template with logo & green cardboard) Page 2 (100 – 200 words)
Page 3 (format given below, to be signed)
Page 3 (general statement)
Page 3 (does not count in 40-page limit)
Page 4 (only counts as 1 page in 40-page limit)
About 6 – 10 pages (details below)
(Sections as appropriate)
Page 40 (only counts as 1 page in 40-page limit) Not part of 40-page limit (may not be read by Assessors)

• The text of the Report must not exceed a maximum of 40 pages in total length. In no circumstances will permission to exceed the page limit be granted; mark penalties will be imposed for overlong Reports. If absolutely necessary, additional material may be included in Appendices. However, Appendices will not necessarily be read in detail by the examiners. The typeface used must be 11 pt or 12 pt and the margins must be at least 20 mm wide on all sides of the page (the page number may be put in the marginal area, clearly away from the edge of the paper).
• The main body of text should be preceded by a Title Page (page 1), a page with an Abstract 100 – 200 words long (page 2), a page containing a Statement of Originality (see below) together with Acknowledgments and a Statement of Contribution of the Student, which explain exactly what parts of the work are yours and what roles were played by others (page 3). You may place the Statement of Contribution of the Student on a separate page, but it will not be counted as an extra page in the 40-page limit. The last part of your preamble should be a Table of Contents (page 4), and if this takes more than one page, only one page counts toward the limit. These 4 initial pages are included in the 40–page limit.

• You must acknowledge all assistance from staff and others under the headings Acknowledgements and Statement of Contribution of the Student on the 3rd page of the report, explaining their role briefly but precisely. You may give a general statement thanking people in the Acknowledgements, but the Statement of Contribution of the Student must be more explicit. You must give details of contributors to the project. For example, were you part of a team who performed the experiment, did someone write parts of the computer code, take the observations, build some of the apparatus, or do some of the analytic work? The reason for this Statement is to assist the assessment of the Reports, which are typically written in the third person like research publications. You are also required to provide on this page a signed and dated statement of originality of the form: I certify that this thesis contains work carried out by myself except where otherwise acknowledged.

• The text itself should be divided into sections with appropriate headings. After a brief Introduction, you are asked to present a section of about 8 pages which surveys the subject of your project and explains how the topic of your work fits into the bigger picture (this section could be given the heading Survey of the Subject, Literature Review, or similar). To prepare this you will need to consult the literature, a task you are advised to undertake early in the year. A section giving the outline, motivation for your project and significance of your results should be included here. A draft Literature Review is to be submitted to the Honours Co-ordinator (and your Supervisor) early in the second semester of your project work.
• Diagrams (with captions) should be inserted in the text at the appropriate locations.
• References within the text should be indicated either by numbers in square brackets (in which case the list of references at the end of the Report should be in order of reference number) or by authors’ names and year (in which case the list of references should be ordered alphabetically by name of first author). If the references, which should be listed at the end of the Report, take more than one page then only one page will count towards the 40–page limit.

• You may wish to use a physics journal as a guide to format for references and other aspects of the thesis. Not all journals follow the same rules; however any major journal would provide an acceptable guide. Suggestions: Astrophysical Journal, journals published by the American Institute of Physics (e.g. Phsyical Review, Journal of Applied Physics, etc.), journals published by the Institute of Physics (Journal of Physics A, B, C, etc.).

• Reports must be on A4 paper and bound in School of Physics covers (available from the Student Support Office or the Store). Four double-sided copies of the thesis are required to be submitted to the Honours Coordinator, PLUS copies for each of your supervisors.
• For information on scientific writing style consult the American Journal of Physics Style Manual (shelved at R530.149/1B/2 in the Physics Library).
• For help with English language usage there are many references. For example:
The Elements of Style, W. Strunk, and E. B. White.
Fowler’s Modern English Usage, W. H. Fowler.

The Complete Plain Words , E. Gowers.
The Oxford Guide to English Usage, E.S.C. Weiner.
Right Words - A Guide to English Usage in Australia, S. Murray-Smith.
4.2.2 Presentation
A high standard of presentation is required, using a word processor which can produce scientific notation. The document preparation system LATEX , which was used to prepare this document, is recommended. Ask staff or students in your department how you can obtain access to LATEX and become familiar with it early in the year. You may also use Microsoft Word if you prefer. It is advisable to discuss the format of your Report with your Supervisor. An electronic version of a template in each of these two major format styles will be available from the Honours Coordinator The facilities of the School can be used for producing diagrams, photographs, and for photocopying.
4.2.3 Deadlines
It is desirable that you start thinking about the content of your thesis as early as possible and discuss it with your supervisor. Specific deadlines are listed in the Important Dates section at the start of this booklet.
4.3 Assessment of Honours Projects
4.3.1 Criteria for Talk Assessment
Broadly, each 20–30 minute presentation will be assessed on the basis of form (the way the material is organized and presented), content (the extent of the material covered), and style (your personal delivery of the presentation – confidence, responsiveness to questions, etc.), with approximately equal weightings.
4.3.2 Criteria for Thesis Assessment
Some of the criteria for this assessment are listed below. The external examiners will in general not be able to judge criterion (4) and the first part of (3) in their assessment.
1. Understanding
• Perception of the problem.
• Applicability of the method used.
• Experimental or theoretical insight.
2. Originality
• What new ideas and novel methods were used.
• What were the modifications and adaptations of existing methods. 3. Effort
• A judgement of the diligence of the student.
• The content of the Report.
4. Independence
• How much assistance did other group members and the supervisor give.
5. Professionality
• Literature survey.
• Critical judgement of data/results and their significance.
6. Presentation
• Ease of reading.
• Clarity of presentation.
• Informative introduction and conclusion.
To standardise grades, the examiners will refer to these criteria:
• 0 – 64 Fail. Unacceptable effort.
• 65 – 69 Hons III. Minimum acceptable to pass Honours.
• 70 – 74 Hons II.2. Capable of proceeding to MSc in some circumstances, but further postgraduate study would depend on an assessment at the end of the 1st year of MSc.
• 75 – 79 Hons II.1. Certainly capable of MSc; probably PhD.
• 80 – 91 Hons I. High standard of work and undoubted research capability. Evidence of independent thought and dedication abd is certainly acceptable directly into a PhD program.
• 92 – 94 Hons I and possible University Medal. An outstanding student showing exceptional achievement. Some conditions apply regarding eligibility for an award of a Medal.
• 95 – 100 Hons I and likely University Medal. An outstanding student showing independent thought, comprehensive knowledge of the subject, and exceptional achievement. Some conditions apply regarding eligibility for an award of a Medal.

5 Projects available in 2009

A short description of the work carried out by the different Research Groups is now given, followed by a listing of project titles, supervisor contact details and a paragraph describing each of the projects. The titles represent only some of the opportunities available for research projects and you are welcome to explore other possibilities in your field of interest with potential supervisors in the School of Physics.

It is very important to choose a project and supervisor to suit your interests and skills. You are strongly encouraged to have discussions with several possible supervisors before making a decision. Speaking to current Honours and postgraduate students will also give you valuable feedback. The Web of Science, accessible from the Library website, will give you information on the research activity of the School’s academics. You should also read the Research pages on the School’s website (http://www.physics.usyd.edu.au/research.html) for more information on the different areas that are currently being researched.

Students should decide upon projects as early as possible — well before the start of their first semester of project work. You should aim to start 3 weeks before the start of lectures. This will enable you to get your project under way before lectures and assignments compete for your time.

Students should make certain that their proposed supervisor will not be absent for protracted periods during semester, unless an associate supervisor is also involved. These issues will need to be formally settled when you submit your Research Plan, two weeks after the start of your first Semester as an Honours student.

Honours students are expected to continue working in their Research Groups during the normal undergraduate vacation periods, except for the designated rest period for students commencing in the July Semester (see Important Dates section).

5.1 Overview of Research Areas
APPLIED & PLASMA PHYSICS:
Projects: p. 20
(1) Biomaterials and Materials Processing with Plasmas
Name Room Prof Marcela Bilek 407
Dr Bee Kwan Gan 366
Dr Dixon Kwok 367
Dr Sunnie Lim
Prof David McKenzie 441
Dr Richard Morrow
Dr Richard Tarrant 366
Dr Yongbai Yin 438
Phone email
9351 6079 m.bilek@physics.usyd.edu.au 9351 5970 bkgan@physics.usyd.edu.au 9351 5972 d.kwok@physics.usyd.edu.au 9351 3311 shnlim@physics.usyd.edu.au 9351 5986 mckenzie@physics.usyd.edu.au 9351 5984 r.morrow@physics.usyd.edu.au 9351 5970 r.tarrant@physics.usyd.edu.au 9351 4756 yyin@physics.usyd.edu.au

Plasmas are being developed for specific tasks in the processing of materials. Plasmas offer a source of ions and electrons whose flux and energy can be tailored by applying voltages to the workpieces. We are applying this technique to produce specific modifications of surfaces with applications in medicine and engineering. We have developed and patented a plasma technology utilising high energy ions for activating polymer surfaces to attach proteins and retain their activity.The attachment of bioactive proteins to surfaces underpins the development of biosensors and diagnostic arrays for detecting disease. There are a number of student projects available, all of which will allow the student to learn about the physics governing the response of protein molecules to surfaces and to become familiar with one or more analysis methods.
(2) Centre for Quantum Computer Technology
Name Room Phone email
Prof David McKenzie 441 9351 5986 mckenzie@physics.usyd.edu.au
Dr Oliver Warschkow 433A 9036 9085 O.Warschkow@physics.usyd.edu.au

The Centre for Quantum Computer Technology is an Australian multi-university collaboration undertaking research on the fundamental physics and technology of building, at the atomic level, a solid state quantum computer in silicon together with other high potential implementations. The objective is underpinned by a vigorous semiconductor research program that includes a sophisticated quantum measurement capability at ultra-low temperatures. The School of Physics at the University of Sydney is a Node of the Centre providing support for the experimental programs through atomistic modelling.
Established in January 2000 through funds from the Australian Research Council and participating institutions, the Centre has nodes at the following institutions, in addition to the University of Sydney; University of New South Wales, University of Queensland, University of Melbourne, UNSW@ADFA, Department of Defence, Griffith University and Macquarie University. The nodes maintain an important collaboration on this project with Los Alamos National Laboratory in the United States. The Centre encompasses major research infrastructure at each of the eight nodes, including an extensive semiconductor nanofabrication facility, crystal growth, ion implantation, surface analysis, laser physics, high magnetic fields/low temperatures, and has substantial theoretical support including advanced atomistic modelling.
(3) Fusion Studies
Name Room Phone email
Dr Joe Khachan 363 9351 2713 khachan@physics.usyd.edu.au
The Centre for Fusion Studies draws together an experimental effort in Electrostatic Ion Confinement, fusion theory and basic plasma physics. The current research activities of the fusion studies group are: compact fusion sources, plasma spectroscopy, plasma modelling and theory, spacecraft ion thrusters. Members of the research group have affiliation with the Applied and Plasm Physics Research Group, the Space and Solar Physics group, the National fusion facility in Canberra, and the U.K. Atomic Energy Authority.
ASTROPHYSICS:
Projects: p. 24
Name Room Phone email
Prof Tim Bedding 558 9351 2680 bedding@physics.usyd.edu.au Prof Joss Bland-Hawthorn 323 9351 2621 jbh@physics.usyd.edu.au Dr Hans Bruntt 565 9351 3041 h.bruntt@physics.usyd.edu.au Dr Julia Bryant 563 9351 2152 j.bryant@physics.usyd.edu.au Dr Shami Chatterjee 570 9351 5577 s.chatterjee@physics.usyd.edu.au Dr Scott Croom 561A 9036 5311 scroom@physics.usyd.edu.au Dr Simon Ellis 464 9036 5464 sce@physics.usyd.edu.au Prof Bryan Gaensler 556 9351 6053 bgaensler@usyd.edu.au Prof Anne Green 564 9351 2727 agreen@physics.usyd.edu.au Dr Lisa Harvey-Smith 559A 9036 5106 lhs@physics.usyd.edu.au Dr Andrew Hopkins 569 9351 7688 ahopkins@physics.usyd.edu.au Prof Dick Hunstead 567 9351 3871 rwh@physics.usyd.edu.au Dr Mike Ireland 554 9036 6518 mireland@physics.usyd.edu.au Dr Helen Johnston 563 9351 2152 helenj@physics.usyd.edu.au Dr Torgny Karlsson 464 9036 5464 torgny@physics.usyd.edu.au Dr Lucyna Kedziora-Chudczer 105 9351 2637 lkedzior@physics.usyd.edu.au Dr Laszlo Kiss 561 9351 4058 L.Kiss@physics.usyd.edu.au A/Prof Geraint Lewis 560 9351 5184 gfl@physics.usyd.edu.au Dr Qinghuan Luo 455 9351 2934 luo@physics.usyd.edu.au Dr Greg Madsen 559A 9036 5106 madsen@physics.usyd.edu.au Prof Don Melrose 454 9351 4234 melrose@physics.usyd.edu.au Dr Miroslav Micic 554 9036 6518 m.micic@physics.usyd.edu.au Dr Tara Murphy 565 9351 3041 tara@physics.usyd.edu.au Dr Stephen Ng 570 9351 5577 ncy@physics.usyd.edu.au Dr John O’Byrne 568 9351 3184 j.obyrne@physics.usyd.edu.au Dr Gordon Robertson 562 9351 2825 g.robertson@physics.usyd.edu.au Prof Elaine Sadler 555 9351 2622 ems@physics.usyd.edu.au Dr Dennis Stello 560A 9036 5108 d.stello@physics.usyd.edu.au A/Prof Peter Tuthill 566 9351 3679 p.tuthill@physics.usyd.edu.au Dr Mike Wheatland 463 9351 5965 wheat@physics.usyd.edu.au
Research in the Institute of Astronomy is grouped in two main areas, Observational Astrophysics and Computational and Theoretical Astrophysics.
Observational data are obtained from various facilities in Australia and overseas, as well as observatories in orbit. In addition to the national facilities — the Anglo-Australian Telescope and the Australia Telescope — the School operates its own radio telescope, the Molonglo Observatory Synthesis Telescope (MOST), while the Sydney University Stellar Interferometer (SUSI) is the major element in a broad program of high resolution optical imaging.
Research is conducted in many exciting areas over a wide range of wavelengths, including solar and stellar astrophysics, asteroseismology, black-hole binary systems, masers, pulsars, supernovae and their remnants, the interstellar medium and the Galactic centre. Beyond our Galaxy, topics include normal galaxies, the Magellanic Clouds, clusters of galaxies, active galaxies and quasars.

Computational and theoretical studies delve into areas of astrophysics that can only be addressed through analytical techniques, computer modelling, or numerical simulation. These include black-hole accretion, interstellar scintillation, planetary and solar emission, pulsar and magnetar radiation mechanisms, gravitational lensing, dark matter, general relativity, and cosmology.
BIOPHYSICS:
Projects: p. 32
Name Room Phone email
Dr Serdar Kuyucak 351 9036 5306 serdar@physics.usyd.edu.au Dr Swarna Patra 361 9036 6008 swarna@physics.usyd.edu.au Dr Denis Bucher 361 9036 5389 dbucher@physics.usyd.edu.au

Biophysics is a rapidly developing research area that employs experimental and theoretical methods of physics to study biological systems. During the last two decades, structures of many molecular machines that control biological processes have been determined, and the current challenge is to understand the dynamics of their operation, i.e. uncover the structure- function relationships. Physicist have a lot to contribute to this frontier area that requires modeling of biological systems at different time scales using quantum, classical and stochastic dynamics. A few sample projects are listed. More can be found in the Biophysics web page: http://www.physics.usyd.edu.au/biophys/. Of course,there are many other open problems in biophysics. If you are interested in pursuing a particular problem that is not listed, we would like to hear about it.
COMPLEX SYSTEMS: Projects: p. 33
Name
Prof Iver Cairns
Dr Qijin Cheng
Dr Neil Cramer
Dr Igor Denysenko
Dr Peter Drysdale
Dr Pulin Gong
Dr Jong-Won Kim
Dr Roman Kompaneets
Dr Igor Levchenko
Dr Bo Li
Dr Vasili Lobzin
Dr Peter Loxley
Hon Prof Kostya (Ken) Ostrikov Dr Chris Rennie
Prof Peter Robinson
Dr Alex Samarian
Dr Yuriy Tyshetskiy
Prof Sergey Vladimirov
Dr Hyunjin Yoon
Room Phone email
383 9351 3961 cairns@physics.usyd.edu.au 372 9036 7959 qcheng@physics.usyd.edu.au 367 9351 5972 cramer@physics.usyd.edu.au

deny@physics.usyd.edu.au
385 9036 7971 peter@physics.usyd.edu.au
374 9036 9368 p.gong@physics.usyd.edu.au
386 9351 5896 jwkim@physics.usyd.edu.au
386 9036 7972 komp@physics.usyd.edu.au
380 9036 7967 iglev@physics.usyd.edu.au
381 9036 5109 boli@physics.usyd.edu.au
385 9351 3810 v.lobzin@physics.usyd.edu.au
386 9036 6294 loxley@physics.usyd.edu.au
372 k.ostrikov@physics.usyd.edu.au
385 9036 7970 rennie@physics.usyd.edu.au
384 9351 3779 p.robinson@physics.usyd.edu.au
387 9351 5959 a.samarian@physics.usyd.edu.au
380 yuriy@physics.usyd.edu.au
382 9351 5770 s.vladimirov@physics.usyd.edu.au hyoon@physics.usyd.edu.au

The Complex Systems Group has theoretical, computational and experimental research interests in the analysis and application of physical systems that have complex and/or emergent behavior, including multiscale interactions, self-organisation, nonlinear dynamics, and stochastic processes. These interests fall mainly in the following four areas:

1. Brain Dynamics and Computational Neuroscience
The dynamics and information processing pathways in the brain are of intense research interest worldwide. The cerebral cortex exhibits waves of activity (“brain waves”) that are detected electrically by electrodes on the scalp, or via functional magnetic resonance imaging. We have developed a model of how these waves are related to the underlying structure of the cortex, which is made of around 100 billion neurons. This model yields excellent agreement with experiment and is enabling a new range of diagnostics to be implemented. It reproduces many wave properties, including spectra and several types of nonlinear seizure, and was awarded a Eureka Prize. There is much yet to be done in areas ranging from pure theory to data analysis and experiment, often in conjunction with psychologists, medical staff, and Brain Resource Ltd, whose Brain Resource International Database is accessible by us. Some possible projects are listed below, but more are likely to become available. They also form part of Federation-Fellowship and other research programs funded by the Australian Research Council. Projects in this area almost invariably lead to publication of one or more papers in scientific journals.

2. Plasma Theory and Applications
In this area, we undertake a wide range of theoretical, computational, and experimental activities involving plasmas in various natural and laboratory contexts. These are described here under the main application areas pursued by the group.

Complex Plasmas
Complex (dusty) plasma is a plasma where a peculiar species of charged dust particles is present. Complex plasmas are ubiquitous in technological applications (e.g., in microchip production, in plasma deposition techniques) as well as in astrophysics (e.g., star and planetary forming regions, planetary rings and cometary tails, interstellar dust clouds, Earth’s magnetosphere and ionosphere). Complex plasmas are often characterized by strong coupling, i.e., the interaction energy of dust particles can exceed their thermal kinetic energy, leading to formation of liquid-like and solid-like states. The field of complex plasmas has experienced explosive growth over the past ten years. The number of research groups working on problems in a complex plasma is now over 100, including a major division at the Max Planck Institute for Extraterrestrial Physics (Germany) leading, in particular, the high-profile experiments on board the International Space Station. This field is a good choice for a student because of its highly interdisciplinary nature (involving plasma physics, technology, material science, astrophysics, etc.), therefore opening various possibilities for future research career.

In addition, some of our most recent research interests go beyond the field of complex plasmas and deal with plasma physics phenomena that are important for fundamental plasma theory as well as for various plasma technologies (e.g., structure and instabilities of the near-electrode region of a gas discharge).

Possible theoretical projects in complex plasmas and general plasma physics are listed below. They also form part of Professorial, QEII, and Harry Messel Fellowships and other research programs recently funded by the Australian Research Council and the University of Sydney. Each of the projects suggested is quite suitable for Honours students and would invariably lead to a paper in an internationally renowned journal. (Prof. Sergey Vladimirov — primary contact).

Plasma Nanoscience, Nanotechnology, Surface Science and Plasma Applications
Nanoscience is one of the most dynamically developing areas of truly interdisciplinary research. Several breakthrough discoveries in the last few years such as nanotubes and fullerens have demonstrated a great potential for applications of nanosized objects. Now, when we can manipulate the individual nano-objects and even atoms on the surface, we face a new global task of inventing ways and methods for manipulating multi-billion ensembles of nano-objects. The most, possibly, remarkable feature of the nano-world is not a nano-size of specific “building blocks”, but actually an enormous number of the blocks to be moved, processed and controlled. It is clear that the classical methods of building nano-world in the “atom-by-atom” way are inefficient, since nobody can control selectively an enormous number of individual nano-objects (just for example, 10 billion of quantum dots per square cm). The nano-world lives by its own rules, and can be controlled only by methods that respect and obey the rules. This situation resembles assembling a huge brick building, so huge that we cannot even dream of laying individual bricks one by one. What could we do in this situation? The only way is to affect our huge heap of bricks in the way to get them self-arrange to create the building on their own. This is not possible in our real macroworld but it is possible in a nanoworld! This sounds like a magic, but the nature really goes this way. From molecules to stars, everywhere we see how a myriad of “bricks” self-organizing into really very complex systems. Thus our task is to “guide” the Nature to assemble the nano-structures by using guided self-assembly. We have developed a range of complex models that enable us to reveal the main self-assembly rules and to invent the tools to control atomic scale processes on the surface. Our research group, which is a lead team of the International Network for Deterministic Plasma-Aided Nanofabrication, works on this problem in a close cooperation with several world-leading universities of the USA, Japan, Singapore, Germany, China, Slovenia, Ukraine, Belarus and other countries, as well as CSIRO. This is an extremely HOT TOPIC (just see recent citation reports in Physics published in Nature!) and any of our projects (with virtually unlimited number of projects, owing to a great variety of exotic nanostructures!) will guarantee numerous publications in prestigious scientific journals and conference presentations, which will give you a competitive edge for future career. The projects can be tailored to suit individual needs and a reasonable proportion of computational/theoretical and experimental can be arranged. Your original research may open new avenues for the creation of new-generation self-assembled nanomaterials, nanoelectronic and photonic structures, functionalities and devices for future computer chips, solar cells, communication systems and biosensors. These projects involve CSIRO Materials Science and Engineering, Lindfield, NSW. Mid-year (July) commencement is also welcome. Space Plasma Physics
Space physics addresses major unsolved problems in our solar system, focusing on the plasma physics. These include solar activity like coronal mass ejections, shocks and radio emissions that propagate from the solar corona to the local interstellar medium, and interactions with the Earth that cause “space weather” with numerous consequences for modern human society. The underlying plasma physics is often fundamental and exciting, including how particles are accelerated, how plasma waves and radio emissions are generated, the properties and stationarity of shock waves, how bursty waves develop in non-uniform media, and nonlinear processes. The group thus works extensively on the fundamentals of plasma theory and simulations, including the world’s first large-scale simulations of electromagnetic plasma turbulence, currently under way.

The Space Physics Group contains a Federation Fellow, an Australian Professorial Fellow, 3 other postdoctoral fellows, and multiple students. It has experts in theoretical analysis, simulations, analyses of observational data, and comparing quantitative theoretical predictions with observations. Profs Cairns and Robinson are Co-Investigators on NASA’s twin-spacecraft STEREO mission, launched in October 2006 and producing novel data. Prof. Cairns is also strongly involved in the new Murchison Widefield Array radiotelescope project being developed in Western Australia, as well as in analysis of data from NASA’s recent rocket TRICE flown into the northern auroral region. Other data come from multiple international collaborations and Australian sources.

Projects in space physics almost invariably lead to publication of one or more papers in scientific journals. These projects range from analytic and numerical theory to computational to observational to combinations of all four techniques. Additional projects to those listed below are possible.
CONDENSED MATTER PHYSICS:
Projects: p. 44
Name Room Phone email
Prof Catherine Stampfl 343 9351 5901 stampfl@physics.usyd.edu.au Dr Carl (Xiangyuan) Cui 344 9036 5301 carlc@physics.usyd.edu.au Dr Simone Piccinin 361 903 65389 piccinin@physics.usyd.edu.au Dr Katawut Chuasiripattana 361 903 65389 katawut@physics.usyd.edu.au Dr Aloysius Soon 361 903 65389 aloysius@physics.usyd.edu.au

Condensed matter physics is concerned with understanding the properties of solids and liquids and is the largest field of contemporary physics. In the condensed matter theory group, fundamental research is carried out on the basis of first-principles theory calculations, into the energetics, atomic, electronic, and magnetic properties of polyatomic systems. Such calculations can significantly contribute to the understanding, engineering, and design of complex materials; for example, catalysts with greater selectivity and efficiency, and new electronic devices. Research in this field forms part of the Federation Fellowship of Prof Catherine Stampfl.
HIGH ENERGY PHYSICS: Projects: p. 45
Name Room Dr Kevin Varvell 355
Dr Bruce Yabsley 366
Dr Aldo Saavedra 366
Hon A/Prof Lawrence Peak 110
Dr Andrew Bakich 106
Phone email
9351 2539 K.Varvell@physics.usyd.edu.au 9351 5970 B.Yabsley@physics.usyd.edu.au 9351 5970 A.Saavedra@physics.usyd.edu.au 9351 2624 L.Peak@physics.usyd.edu.au 9351 2638 A.Bakich@physics.usyd.edu.au
High Energy, or Particle, physics involves the study of the world of subatomic particles and the forces via which they interact.
(1) The ATLAS Experiment
ATLAS is one of the detectors under construction for the LHC (Large Hadron Collider) situated at the European Laboratory for Particle Physics. The LHC begins operation in the second half of 2008 and it will be the highest energy accelerator in the world, colliding protons on protons with a centre of mass energy of 14 TeV. By 2009 the first data from ATLAS will be available so it is a very exciting time for the field. The primary physics goal of ATLAS is to search for the Higgs boson. In addition it will provide a rich environment to study many aspects of particle physics such as CP violation in B meson decays, top physics and QCD. Searches for new physics beyond the Standard Model such as supersymmetry and extra dimensions will also be a major focus. An international collaboration composed of more than 1700 physicists from approximately 150 different institutes and universities all over the world are involved in the building (and soon running) of the ATLAS detector. The projects described later are examples of those that can be offered on ATLAS – it is not meant to be an exhaustive list. See also
http://www.physics.usyd.edu.au/hienergy/index.php/Possible Student Projects

(2) The Belle Experiment
Belle is an exciting experiment taking place now at the National High Energy Physics Laboratory KEK in Japan, studying, amongst other things, the violation of CP symmetry. C (the charge conjugation operation) is the process of interchange of particles and antiparticles in a given system, and P (the parity operation) is the process of reflection of the system through the origin – effectively a mirror reflection. Belle studies CP using the weak interactions of B mesons (heavy mesons containing the “bottom” quark). The results from Belle may well give us some insight into why we live in a matter rather than an antimatter universe, as weak interactions of this type had a pivotal role in shaping the Universe in its very earliest stages of formation. The Sydney High Energy group is actively involved in this frontier experiment. Data taking commenced back in the northern summer of 1999 and is ongoing. So far, over 700 million BB pairs have been collected, and positive results on CP violation in the B system have been obtained. Large samples of e+e− → q¯ continuum, tau-pair and other kinds of events are also available. The projects described later are examples of those that can be offered on Belle – it is not meant to be an exhaustive list. See also http://www.physics.usyd.edu.au/hienergy/index.php/Possible Student Projects
MEDICAL PHYSICS:
Projects: p. 47
Name Room Phone email
Prof Clive Baldock 415 9351 8731 c.baldock@physics.usyd.edu.au A/Prof Roger Fulton 0431 872 415 r.fulton@physics.usyd.edu.au Dr Zdenka Kuncic 464 9351 3162 Z.Kuncic@physics.usyd.edu.au A/Prof Steven Meikle Brain & Mind Research Institute 9351 0847 s.meikle@usyd.edu.au

Medical Physics is the field in which physical scientists apply their knowledge and skills to many different areas of medicine including the treatment of cancer, medical imaging, physiological monitoring, medical electronics, and radiation transport modelling. In the application of the physical sciences to the treatment of cancer, for instance, the aim is to develop new and more effective methods for administering radiotherapy and to assist radiation oncologists in studying the medical impact of new radiotherapy technology. To this end, research focuses on calculating, measuring, and verifying radiation dose (the amount of energy deposited per unit mass of tissue) to ensure that an accurate amount is delivered to a well-defined treatment volume. The fundamental physical interactions of different types of ionising radiation (electrons, photons, protons and heavier nuclei) are modelled to research treatment techniques, treatment apparatuses, radiation measurement devices, quality assurance methods, dose calculation methods, and methods of predicting the effects of radiation on tissue. In medical imaging applications, physicists apply their skills to the development of instrumentation (for imaging x-rays, gamma rays and non-ionising radiation), image reconstruction algorithms, models of photon transport and detection, and models of the underlying physiological processes. The broad aim of this field of research is to improve the resolution, signal-to-noise ratio and quantitative accuracy of non-invasive imaging techniques, within the constraints of radiation dose to the subject and duration of the procedure. This area of medical physics is undergoing rapid growth as functional imaging techniques such as PET and SPECT become increasingly used as a tool for basic biomedical research as well as a routine clinical procedure.
PHOTONICS AND OPTICAL SCIENCE (IPOS): Projects: p. 51
(1) CUDOS
Name Room Prof Martijn de Sterke 307
Prof Ben Eggleton 313
Dr Christian Grillet 303B Dr Christian Karnutsch 226D Dr Boris Kuhlmey 312
Dr Erik Magi 218
Prof Ross McPhedran 309
Dr Christelle Monat 305
Dr Nicolae Nicorivici 318
Dr Mark Pelusi 314
Dr Mike Steel 304B Dr Snjezana Tomljenovic-Hanic 314
Phone email
9351 2906 desterke@physics.usyd.edu.au 9351 3604 egg@physics.usyd.edu.au 9036 9430 grillet@physics.usyd.edu.au 9351 3958 c.karnutsch@physics.usyd.edu.au 9351 2544 borisk@physics.usyd.edu.au 9036 5206 magi@physics.usyd.edu.au 9351 3872 ross@physics.usyd.edu.au 9351 7697 monat@physics.usyd.edu.au 9351 2546
9351 3953 m.pelusi@physics.usyd.edu.au 9351 6061 mike@rsoftdesign.com
9351 3953 snjezana@physics.usyd.edu.au An underlying theme of the CUDOS research is the “processing” of short pulses of light (down to 100’s of femtoseconds). One aspect of this research is that electronics cannot cope with such fast processes and thus only way for this processing to occur is all-optically, i.e., using other light! Now in standard, linear optics, two different light beams do not interact with each other and so the optical processing of light is impossible. That’s why we use nonlinear optics, by which one beam of light can change the phase of another, new frequencies can be generated, or solitons can form, to name just a few examples. Though much of our work involves standard glass, it is one of the least nonlinear materials known, and so nonlinear processes requires high intensities (100’s of MW/cm^2 to GW/cm^2. This is the reason why we are also working with chalcogenide glasses, which contain elements like sulphur or selenium, since nonlinear effects in these materials are about 1000 times stronger than in ordinary glass.

We want the processing of light to occur in small volumes so that they are fast and efficient. This is why photonic crystals and photonic crystal fibres are amongst our research interests. In these structures the refractive index varies periodically with position, which in practice is usually achieved by the inclusion of periodically spaced air holes in the structure. The periodicity gives rise to a photonic band structure with photonic band gaps, where light cannot propagate through the structure, leading to the ability to manipulate light to an unprecedented degree. A particularly dramatic example of this is the manipulation of the spontaneous emission of an atom. Much of our research aims to clarify the properties of these structures.
(2) Optical Fibres
Name Room Dr Alex Argyros 604
Dr Sergio Leon-Saval 604
Dr Maryanne Large 438
Dr Martijn van Eijkelenborg 604
email
a.argyros@usyd.edu.au sergiol@usyd.edu.au
m.large@usyd.edu.au
m.eijekelnborg@usyd.edu.au

A particular speciality is of this group is microstructured, or photonic crystal fibres. It was the first group to make these fibres in polymer, and is now the world leader in this area. It also has a leading role in the development of both developing new algorithms to model microstructured fibres, and to address the complex task of inverse design. Much of this design work has been biologically inspired, using techniques such as genetic algorithms, embryogeny and cellular automata. A related activity we have pursued is biomimetics, in which we try to exploit designs that have emerged from nature.

The projects listed here are intended to be indicative only. Students interested in these areas should contact the academics concerned well before the projects are to start, and could be redefined in light of the interests and abilities of the students.
QUANTUM PHYSICS: Projects: p. 59
Name Room Dr Stephen Bartlett 317
Dr Yeong-Cherng Liang 364
Dr David Jennings 364
Dr Owen Maroney
Dr David Reilly 357
Dr Hans Westman 364
Phone email
9351 3169 bartlett@physics.usyd.edu.au 9351 2712 y.liang@physics.usyd.edu.au 9351 2712 davidj@physics.usyd.edu.au omaroney@physics.usyd.edu.au 9351 8167 reilly@physics.usyd.edu.au 9351 2712 hwestman@physics.usyd.edu.au
The Quantum Physics group is focussed on three research areas: Mesoscopic Physics, Quantum Information Theory, and the Foundations of Quantum Physics.
Mesoscopic Physics
Mesoscopic Physics is a new experimental group in the School of Physics at the University of Sydney. The focus of our research is mesoscopic physics, the behavior of matter on scales below a micron, where quantum mechanical effects become important. We are interested in low temperature experiments that probe quantum objects such as single electron charges or spins, often on nanosecond time scales. Potential applications of this work include quantum information processing and new technology for biomedical sensing and imaging.

Quantum Information Theory
What does quantum physics have to say about information processing? What are the physical limits on transmitting, storing, and processing quantum information? The answers to these questions will have implications for both future technologies and fundamental quantum physics and is the topic of the exciting new interdisciplinary field of Quantum Information Theory. In the Quantum Information Theory group, we explore these questions and more, developing insights into quantum physics and the laws of the universe.
Foundations of Quantum Physics
Quantum foundations concerns the conceptual and mathematical underpinnings of quantum theory. The Quantum group in the School of Physics is embarking on an exciting new research collaboration with Prof Huw Price at the Centre for Time (in Philosophy) and the Perimeter Institute for Theoretical Physics in Canada – the premiere research centre for quantum foundations.
SYDNEY UNIVERSITY PHYSICS EDUCATION RESEARCH (SUPER): Projects: p. 61
Name Room Phone email
Dr Manjula Sharma 226E 9351 2051 m.sharma@physics.usyd.edu.au Dr John O’Byrne 568 9351 3184 j.obyrne@physics.usyd.edu.au Dr Ian Sefton 502 9351 5982 I.Sefton@physics.usyd.edu.au

Physics education research (PER) is a relatively new field in which you learn the intricacies of physics, as well as analyze how physics is learnt and taught. Physics is considered a complex knowledge domain and PER informs a wide range of areas, from multimedia, learning theories to instructional practice. Checkout the SUPER publications to get a feel for the range of areas – http://www.physics.usyd.edu.au/super/SUPERPublications.htm

You will find that you learn about learning, and indeed, do learn a lot of physics while deciphering the complex and intricate processes. The research is discipline specific and is done within the physics department. The listed projects and the SUPER webpage provide a flavour of possible projects. We invite you to bring forward your ideas of what intrigues you - a physics concept, a model, unifying ideas, demonstrations, learning experiences etc.
THEORETICAL PHYSICS:
Projects: p. 62
Name Room Phone email
Dr Qinghuan Luo 455 9351 2934 luo@physics.usyd.edu.au Prof Don Melrose 454 9351 4234 melrose@physics.usyd.edu.au Dr Mike Wheatland 463 9351 5965 wheat@physics.usyd.edu.au
Theoretical physics is concerned with our description of fundamental physical processes.
Projects in theoretical physics can involve mathematical analysis, numerical analysis and computational modelling. Potential projects involve applications to high-energy astrophysics, plasma physics, solar physics, pulsars, and scintillation.
The Theoretical Physics group has close association with the Institute of Astronomy, and some but not all projects offered have an astrophysical flavour.
5.2 Projects for 2009 by research area

Research Projects in Applied and Plasma Physics
Deposition of new transparent conducting oxide materials (multiple projects available) Supervisors: S. Lim and M.M. Bilek
The recent growth of information technology and the need for energy efficiency have significantly increased the demand for optically transparent, electrically conducting coatings. Indium tin oxide (ITO) is currently the most popular transparent conducting oxide (TCO). However, limited reserves of indium mean that ITO cannot continue to meet the growing demand. Furthermore, the range of substrates on which indium tin oxide can be used is limited due to its brittleness and the need for high deposition temperatures. In this wide reaching research program, we aim to synthesize new binary and ternary conductive metal oxide alloys by developing methods to produce good quality TCOs at low temperature. The synthesis methods to be used are cathodic arc and sputtering, both of which allow the manipulation of ion energy and flux with magnetic and electric fields. The effects of energetic ion bombardment on the crystallinity and mobility of charge carriers in the films will be studied. Students will gain experience on state of the art X-ray diffractometers, semiconductor parameter analyser and liquid helium cryostats. Transparency will be assessed using UV-Vis-NIR spectrophotometry and the nature of electrical conductivity will be studied using four point probe and Hall measurements. The stoichiometry of the deposited films will be determined by SNMS (secondary neutral mass spectroscopy) and their structure determined using electron microscopy methods. The effect of new co-doping strategies, in which acceptor-donor complexes modify the band structure, to achieve higher carrier densities by reducing the dopant activation energies, will be studied. A range of projects, both theoretical and experimental are available.
Synthesis of MAX phases using a high powered pulsed plasma (multiple projects available) Supervisors: M.M. Bilek and DR McKenzie
The MAX phases represent a new class of compounds which have unique properties that can be related to their layered (nanolaminate) crystal structure. They are expected to have high thermal and electrical conductivities and to be machineable like metals, but also highly resistant to oxidation and thermal shock like ceramics. The MAX phases are made up of an early transition metal M, an element from the A groups, usually IIIA and IVA, and a third element, X, which is either nitrogen or carbon, in the composition Mn+1AXn, where n is 1, 2 or 3. Difficulties in achieving phase pure samples have hindered property determination to date. We have developed a deposition strategy that enables the accurate composition required to achieve phase pure samples. Recently we have achieved the first synthesis of a pure MAX phase using cathodic arc deposition. In this work program we plan to synthesize new members of the MAX family and to measure their properties. X-ray diffraction, IR spectroscopy and TEM will be used to confirm MAX phase crystallography prior to property characterisation. Property measurement will include anisotropic electrical properties as a function of temperature, sliding coefficient of friction and mechanical properties such as hardness, and thermal stability. Thermal stability is crucial for applications in high efficiency engines and will be assessed using a state of the art X-ray diffractometer capable of collecting high resolution diffraction patterns at high temperatures. Experiments under reactive and nonreactive atmospheres will show oxidation behaviour as well as diffusion of species in the structure and crystallographic phase transitions driven by temperature will be identified. A range of projects are available.
High Power Pulsed Magnetron Sputtering-arc or Glow
Supervisors: M. Lattemann, D.R. McKenzie, M.M.Bilek
High power pulsed magnetron sputtering is a new method for producing a highly ionised flux of material from a solid target for coating applications. The nature of the plasma produced when high power pulses are applied to a sputtering target is the subject of current research in laboratories in Sweden, Germany, USA and in Australia. Further progress depends on understanding whether the discharge is similar to a high current arc or is a new kind of glow discharge operating at a much higher current density than previously known. An arc involves a localised emission site on either the cathode or the anode whereas a glow discharge has a distributed current on the electrodes. A glow discharge is more controlled than an arc and does not produce macroparticles. We will apply plasma diagnostics to decide between the two models of the HIPIMS discharge. High speed high dispersion optical spectroscopy will be applied to determine the ion density and ion energy in the plasma. Langmuir probes will be used to investigate the electron temperature. The data will be interpreted in terms of the two models of the HIPIMS plasma.
Surfaces for attachment of biomolecules for biosensors and protein microarrays (multiple projects available)
Supervisors: M.M. Bilek, D.R. McKenzie, C.G. dos Remedios (Medical Sciences)

The attachment of bioactive proteins to surfaces underpins the development of biosensors and diagnostic arrays for detecting disease. We have developed and patented a plasma technology utilising high energy ions for activating polymer surfaces to attach proteins and retain their activity. We have demonstrated the technology with three enzymes and developed a theory for the chemical and physical mechanisms responsible for their enhanced attachment. In the next phase of the project we seek to test our theory by studying the effects of modifications to the surface chemistry on interactions with a new set of proteins and molecules. The interactions of the proteins with the new surfaces will be examined using a range of methods including infra-red spectroscopy, surface plasmon resonance, ellipsometry, neutron reflectometry and biological activity assays. There are a number of student projects available, all of which will allow the student to learn about the physics governing the response of protein molecules to surfaces and to become familiar with one or more analysis methods. In the course of the project students will interact directly with our research partners in biochemistry, anatomy, CSIRO and ANSTO and learn the research skills required to function effectively in a vibrant, multidisciplinary research environment.

Surfaces for Implantable Medical Devices and Prosthetic Implants: A Collaboration with Industry (Cochlear Ltd, Spinecel Ltd and the Royal Prince Alfred Hospital)
Supervisors: M.M. Bilek, D.R. McKenzie and A. Weiss (School of Molecular and Microbial Biosciences)
NB: due to the commercial nature of this project, students choosing this project will be required to sign an IP agreement.
The demand for implantable medical devices is growing rapidly due to the low availability of transplantable human donor organs coupled with our aging population. This year we have commenced a partnership with two dynamic companies working in this arena. Cochlear is the international leader in auditory implants to for the hearing impaired whilst Spinecel is a supplier of new technologies for bone contacting prosthetic implants, such as replacement hip and knee joints. Both companies are interested in developing surfaces that encourage the in growth and subsequent integration of oesteoblasts (or bone cells) and neurons (nerve cells) to dramatically improve the effectiveness of their products. Cardiologists at the Royal Prince Alfred Hospital are interested in surfaces capable of reducing the incidence of life threatening thrombosis induced by blood contacting implants through protein mediated cellular interactions. These partners are attracted by our newly patented surfaces for linker free covalent attachment of bioactive protein. This project will explore the use of proteins known to recruit cells of the desired type coupled to our protein binding surfaces to promote integration into the relevant biosystem. Techniques that will be used to characterise the surfaces and their protein attachment capability include AFM, surface profilometry, x-ray photoemission spectroscopy, secondary neutral mass spectroscopy, infra-red spectroscopy, contact angle measurement and electron microscopy. In-vitro assays to assess cell attachment and spreading on the protein covered surfaces will be conducted together with colleagues at the School of Molecular and Microbial Biosciences, while in-vivo assessments required for medical industry approval will be conducted by the industry partners. Surface morphology of the surfaces will be investigated as a parameter to optimise the cell-surface interactions.
A Project in Renewable Energy: Protein Attachment for Energy Conversion Supervisors: D.R. McKenzie, M.M. Bilek, Y.Yin, A. Kondyurin and N. Nosworthy
The production of ethanol from agricultural products is becoming a major source of liquid fuels derived from renewable sources to replace oil. However, there are major problems emerging, associated with the diversion of food crops such as corn and sugar cane, into industries supplying fuels for transport. Certain enzymes known as cellulases are capable of breaking down complex cellulose material produced as waste in forestry into sugars that can be processed readily to ethanol. Other enzymes such as hydrogenase can produce hydrogen from organic matter, for use in a future ”hydrogen economy”. These enzymes are currently expensive and can lose their activity when poisoned by products of the reactions they catalyse. This project will investigate the use of plasma activated surfaces to attach the enzymes and preserve their function by designing an appropriate flow process with replaceable functionalised surfaces. The fact that the enzymes are immobilised on a surface enables the process to be more readily controlled and assists in enzyme preservation and management Suitable surfaces will be produced by plasma surface modification of polymers and by depositing a polymer directly from a plasma under energetic ion flux. Such plasma based modification processes have been developed and patented by our group. We have already shown that the surfaces produced covalently attach enzymes such as horseradish peroxidise and preserve their function. The mechanism for the covalent attachment is still under investigation. Our current preferred theory is that free radicals are created on the surface by the plasma process and take part in the binding process. Free radicals can be identified using electron spin resonance (ESR). Students undertaking this project will join a dynamic interdisciplinary team, consisting of physicists, chemists and molecular biologists. The ability of the surfaces to immobilise the enzymes will be studied using ESR as well as surface sensitive techniques such as ellipsometry, quartz crystal microbalance monitoring, surface plasmon resonance, x-ray photoemission spectroscopy and infrared spectroscopy. Retention of the function of the enzymes will be tested in a suitable assay to be developed in the project. The project will also examine the dynamics of the reaction catalysed and devise suitable geometries for a realistic process based on a knowledge of the reaction kinetics.
Ellipsometric Plasmonic Monitoring for Medical Diagnostics
Supervisors: Professors DR McKenzie, MM Bilek
Antibody arrays are a powerful new concept for early disease detection. They rely on the surface attachment of small spots of antibodies which interact specifically with a set of proteins whose relative levels of expression are associated with the onset of the disease to be screened for. We are developing such on chip medical diagnostics by creating surfaces suitable for attachment of antibodies. Crucial to the functioning of such a diagnostic device is the readout mechanism, for detecting the antigens bound to surface attached antibodies.

Ellipsometry uses elliptically polarised light to investigate surfaces through light interactions. Both the phase and the amplitude information available in light are used in ellipsometry. A surface plasmon is an excitation on a metal surface that interacts strongly with light under specific conditions that are influenced by the optical properties of the medium just outside the metal.

In this project, we will use optical theory of thin film multilayers and ellipsometry to test the sensitivity of the surface plasmon resonance phenomenon to the detailed structure of protein rich layers adsorbed on the metal surface or interacting with the proteins attached to it (as in a real device). We will predict the effect of protein attachment density and protein orientation (in the case of proteins that are non spherical) on reflected light. The effect of an electric field on the protein solution will also be predicted and the feasibility of detecting it through ellipsometry will be studied. An electric field applied to a solution containing charged molecules or ions causes a sudden change in concentrations which may be detectable by monitoring the plasmon. The results of the theoretical predictions will be tested using the state of the art ellipsometer in the School and a specially developed prism coupling system. The results of this project will be of direct application to the sensing of protein attachment and protein-protein interactions.
A Super Energy Efficient Vacuum Glazing
Supervisors: Dr Nelson Ng (experiment), Dr Cenk Kocer (simulations) and Prof M Bilek
A highly insulating window pane can be made from two sheets of glass with a sub-millimeter vacuum gap in between. The glass sheets are soldered together at the edges and small stainless steel pillars are used as spacers to maintain the vacuum gap against atmospheric pressure. A product based on this technology, which was developed in the School of Physics in the early 1990’s, is currently being manufactured and sold in Japan. Truly global uptake of this energy saving technology is hampered by the lack of a safety glass version of the product. We are working together with the company that manufactures this product as well as a local glass tempering company to develop a fracture resistant version.

The aim of the experimental and simulation projects would be to gain a deeper understanding of the mechanical processes that influence the ultimate strength of the vacuum glazing, when static and dynamic forces are applied. The breakage of samples under static and dynamic loads will be studied using experimental and theoretical methods that will focus on understanding how energy is conveyed through the complex multicomponent structure. The projects will look closely at the role of internal stresses, material properties, the shape of the pillars, edge seals. Projects are available in experiment or simulations alone, as well as, using a combined approach.
Measuring small surface changes; a study of Laser based optical methods
Supervisors: Cenk Kocer, David McKenzie, Marcela Bilek
For many reasons it is important to have the capability to accurately, and simply, characterize the surface topography of a material. It is well known that small surface undulations significantly affect the properties of a material. Even though the surface changes are often on the nanoscale, the macroscopic properties can be affected strongly. This is particularly the case with brittle materials such as glass. The failure strength and mode of failure, of a glass structure are strongly influenced by the glass surface topography. Clearly, however, characterizing the surface topography of a transparent material is not a trivial task when using optical techniques. In this project a novel laser based optical method is proposed for measuring the surface topography of transparent materials. In particular, the technique will be employed to look at static and dynamic surface variations in glass. The project will consist of not only an experimental component but also a theoretical component to perform numerical simulations of the optics of the experiment.
Vibrational Analysis of a Vacuum Glazing: improving impact resistance
Supervisors: Dr Cenk Kocer, Prof M. Bilek and Prof D.R. McKenzie

With current environmental concerns there has been a growing movement in industry and at home to find ways to increase energy savings. In most homes, and offices, windows are the single largest source of unwanted heat gain and loss. At the School of Physics a highly insulating window pane, called a Vacuum Glazing, was developed in the early 1990’s, and is currently being manufactured and sold in Japan. The window consists of two flat sheets of glass, separated by an array of high strength pillars and hermetically sealed at the edges.

Vacuum glazing provides thermal insulation better than conventional double glazing at only a fraction of the thickness, allowing retrofit installation to single glazed windows. Since there is a highly evacuated space, the atmospheric pressure acting on the surfaces of the glazing is extremely high: about 10,000 Kg m-2. Even though current vacuum glazings are produced to withstand these static surface pressures, the glazing must also exhibit a high resistance to breakage when impacted. In order to understand the deformations induced during impact, and the manner in which impact energies can be dissipated, a vibrational analysis of a vacuum glazing is essential. This project will involve experimental and computational methods to study the vibrational response of a vacuum glazing to an impact. Using this data, design changes will be determined that may lead to a high strength vacuum glazing product.
Indentation of viscoelastic materials: a finite element study
Supervisors: Cenk Kocer, David McKenzie
Indentation testing is a well established and reliable means of determining the hardness, toughness, elastic properties and other material parameters of materials. A hard cylindrical or spherical indenter is pressed onto a material surface and a well known force is applied. The surface deflection as a function of indenter load is used to characterise the elastic and plastic response of a material. Viscoelastic materials are becoming increasingly important in applications that require impact resistance, as in automotive and aerospace applications. Viscoelastic materials show some of the properties of solids in that they recover from distortions and some of the properties of liquids in that their response is time dependent. The use of indentation methods to probe the properties of a viscoelastic material is not trivial and is still in its infancy. In this study, the finite element computational method will be used to simulate the indentation process in materials that show viscoelasticity. Initially, the available viscoelastic material models in the finite element method will be trialled to determine what happens after an indentation is made in the surface. Experimental measurements have been made that show how the profile of the indentation changes with time. Once a model is selected, the indentation process of cyclic loading will be simulated.

Nuclear fusion using Ion Cyclotron Resonance
Supervisor: Joe Khachan
Contact: Joe Khachan, 363, j.khachan@physics.usyd.edu.au, 9351 2713

The ultimate energy source needs to be reliable, abundantly available for at least millions of years, and must be environmentally clean. Nuclear fusion of light elements (i.e. hydrogen, deuterium etc.), which powers the Sun and other stars fulfils all of these criteria. A litre of ordinary drinking water carries enough deuterium to power an average Australian home for a year. In this project, we will be exploring the use of ion cyclotron resonance to produce fusion on a small scale. It is not anticipated that this project will produce a net energy gain, but it is expected to produce fusion. If you are interested in this future energy industry, then this is an entry point into the physics of fusion plasmas. The project can be both experimental and theoretical depending on your natural inclination. The broader picture of our group is to produce a net energy gain from fusion on a small scale. This project fits into this larger outlook.

Research Projects in the Institute of Astronomy

Asteroseismology: probing inside stars using stellar oscillations
Supervisors: Tim Bedding, Laszlo Kiss and Dennis Stello
Contact: Tim Bedding, bedding@physics.usyd.edu.au, 9351 2680

Asteroseismology involves using the oscillation frequencies of a star to measure its internal properties. Measuring stellar oscillations is a beautiful physics experiment: a star is a gaseous sphere and will oscillate in many different modes when suitably excited. The frequencies of these oscillations depend on the sound speed inside the star, which in turn depends on density, temperature, gas motion and other properties of the stellar interior. This analysis, called asteroseismology, yields information such as composition, age, mixing and internal rotation that cannot be obtained in any other way and is completely analogous to the seismological study of the interior of the Earth.

Many stars, including the Sun, are observed to oscillate. Asteroseismology is a new and rapidly developing field and there are several possible Honours projects, depending on the preference of the student. These range from using observations of red giants taken over many decades, to obtaining high-precision Doppler measurements of sun-like stars with large telescopes such as the AAT and the VLT.

The environments of massive galaxies
Supervisor: Julia Bryant, Helen Johnston, Dick Hunstead
Contact: rwh@physics.usyd.edu.au

Radio galaxies have been shown to be the most massive galaxies at every epoch. Current models of galaxy formation cannot readily account for the rapid evolution of these galaxies in the early universe. The environments in which they form play a vital role in accelerating their evolution, and there is now direct evidence that these galaxies live in very dense environments. In this project we have the opportunity to study the environments of powerful radio galaxies at both high redshift and in the nearby universe. By matching deep radio images of a region in the southern sky obtained with the Australia Telescope Compact Array with near-infrared K-band images obtained with the Anglo-Australian Telescope, we have identified several hundred galaxies. The project will involve determining the distribution of possible companion galaxies and looking for connected structures and clustering on a large scale. This is an international project involving scientists from India and Australia.

Using deep true-colour images to find high-redshift clusters
Supervisor: Julia Bryant, Dick Hunstead, Helen Johnston
Contact: rwh@physics.usyd.edu.au

Colour images in astronomy have long been used to identify different stellar populations in our galaxy and in nearby galaxies. In the more distant universe they have been extremely useful in picking out the highest redshift galaxies (e.g., the Hubble deep fields) and locating galaxy clusters and other large-scale structures. We have two sets of deep images at optical and near-infrared wavelengths obtained with one of the twin 6.5-m Magellan telescopes at Las Campanas Observatory in Chile. Each image set is centred on a known high-redshift (z > 2) galaxy first detected through its powerful radio emission. The project will involve combining the multiwavelength images to form a colour composite, and estimating photometric redshifts of surrounding galaxies which will then be used to search for clusters and other structures which may be associated with the radio galaxy.

Measuring the structure of quasar emission regions
Supervisor: Dr Scott Croom
Contact: Scott Croom, 561A, scroom@physics.usyd.edu.au, 9036 5311

The standard model describing active galactic nuclei (AGN) has fast moving gas orbiting the central black hole at radii of light days to months. This is the so-called “broad line region” from which the characteristic broad emission lines in quasar spectra are emitted. The detailed structure of these gas clouds is largely unknown. The aim of this project is to use time variations in the spectra of quasars to place constraints on the physical structure of the broad line region. The student will examine a large database of quasar spectra taken over a period of approximately a decade and extract multiple repeat observations to test for variations in the emission lines. Any such line variations found will be compared to the most recent models of the structure of the broad line region.
Do galaxy mergers make quasars?
Supervisor: Dr Scott Croom
Contact: Scott Croom, 561A, scroom@physics.usyd.edu.au, 9036 5311

We now understand that most massive galaxies in the Universe contain a super massive black hole at their centre, with masses typically 10^6− 10^9 times that of the Sun. These black holes are built up by rapid accretion of gas. For a brief period of time, during this accretion phase the hot gas radiates at high luminosity, giving rise to quasars. But how does the gas get funneled down to a black hole? The most likely cause is that the disturbances caused by major mergers of galaxies can cause gas to feed a super massive black hole.

In this project the student will work with ultra-deep optical (from the Japanese Subaru 8m Telescope) imaging data to find faint high redshift galaxies that are close to accreting quasars. These quasars have been selected using the infrared Spitzer Space Telescope, and so even include objects heavily obscured by dust (more likely in the early stage of a merger). The aim is to see whether these environments are conducive to mergers (i.e., they have a relative high density of galaxies). The deep imaging data can also be used to derive galaxy colours, which are used to test for recent starburst activity in the galaxies nearby the quasars.

Are the most luminous black holes in the biggest galaxies?
Supervisor: Dr Scott Croom
Contact: Scott Croom, 561A, scroom@physics.usyd.edu.au, 9036 5311

Quasars are the most luminous objects in the Universe. They are powered by accretion of gas onto super-massive black holes, with typical masses 10^6− 10^9 times that of the Sun. Most models of quasar formation suggest that the most luminous of quasars should have the most massive black holes, and so sit within the most massive galaxies. To date, there is little direct evidence of this.

The aim of this project is to make a statistical measure of the masses of quasar hosts via clustering analysis. The is a direct theoretical link between the clustering of galaxies and their mass - with the most massive galaxies being the most strongly clustered. The student will apply new techniques such as mark-correlations to determine the luminosity dependence of quasar clustering and so make direct tests of quasar formation models. Double Trouble: Multiple Faraday Rotation Components in Distant Galaxies Supervisors: Prof. Bryan Gaensler (U. Sydney), Dr. Ilana Feain (CSIRO ATNF)
Contact: Prof. Bryan Gaensler, 556, bgaensler@usyd.edu.au, 9351 6053

A remarkable discovery made by 20th century astronomers was that stars, planets, galaxies, and even diffuse interstellar gas, are all magnetic. These cosmic magnetic fields play a vital role in controlling how stars and galaxies form, age and evolve. However, despite the ubiquity of astrophysical magnets, we do not understand what creates them, or how they have maintained their strength over billions of years. And unfortunately, magnetic fields are invisible even to the largest telescopes.

Unique insights into magnetism in the Universe can come from Faraday rotation, in which a polarised radio signal from a distant background galaxy has its angle of polarisation rotated when it passes through a foreground cloud of magnetised gas. Over the last few years, we have been using Australian radio telescopes to measure the Faraday rotation for thousands of distant galaxies, so that we can map out the magnetism in foreground gas clouds in the Milky Way. However, we have found that in about 10% of cases, the polarised radio wave has been rotated twice: once in the galaxy producing the radio emission, and again when the polarised radio signal passes through the Milky Way. And the magnetic field strength implied by the first rotation is often extremely high. In this project, a student will define a sample of radio galaxies that show two separate Faraday components, and will use astronomical databases and archival observations to measure properties of these sources such as galaxy type, redshift, infrared luminosity and spectral index. With these data, we can determine what produces the additional Faraday rotation component seen in these sources, and can calculate the geometry and strength of the magnetic fields in these unusual objects.

Is the Magellanic Bridge Magnetic?
Supervisors: Prof. Bryan Gaensler, Dr. Greg Madsen
Contact: Prof. Bryan Gaensler, 556, bgaensler@usyd.edu.au, 9351 6053

The two nearest galaxies to us, the Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC), are connected by a stream of gas 50 000 light years long. This feature, known as the “Magellanic Bridge”, is thought to correspond to gas torn off the LMC and SMC during a close encounter between the two galaxies approximately 200 million years ago. Remarkably, the Magellanic Bridge contains many stars that belong neither to the LMC nor SMC, but which were born in the Bridge itself.

This isolated environment provides a unique laboratory. We know that in a typical galaxy, stars need magnetic fields to form, and we know that supernova explosions from these stars then help to arrange and amplify these magnetic fields. But is there a magnetic field in the Magellanic Bridge? In this project, a student will search for Faraday rotation in the polarised radio emission from radio galaxies behind the Bridge, and will thus carry out the first ever search for magnetism in this unusual region. The results of this experiment will provide vital clues as to the role of magnetism in forming stars, and to the role of stars in making magnetic fields.

Revealing the Magnetic Field of the Spiral Galaxy NGC 1310
Supervisor: Prof. Bryan Gaensler
Contact: Prof. Bryan Gaensler, 556, bgaensler@usyd.edu.au, 9351 6053

The Milky Way and many other nearby spiral galaxies all show well-organised, large-scale magnetic fields. The existence of magnetism on these large scales points to a powerful and ubiquitous process which organises random motions into highly-ordered structures. The dynamo mechanism (in which small-scale turbulent magnetic fields are amplified and ordered by cyclonic motions and differential rotation) is the favoured explanation to account for this structure. However, dynamos are not fully understood and still face theoretical problems.

It is difficult to study magnetic fields in most other galaxies, because these sources are millions of light years away, and their emission is faint. In this regard the spiral galaxy NGC 1310 provides a unique opportunity, because it sits in front of a bright lobe of polarised radio emission expelled by the supermassive black hole known as Fornax A. In this project, a student will analyse radio telescope data on the lobe of Fornax A, and will use the effects of Faraday rotation through NGC 1310 to make the most detailed map ever made of magnetic fields in a distant galaxy. This will result in the first study that coherently links small-scale turbulence and large-scale magnetic fields in the same galaxy.

Magnetic Turbulence in the Large Magellanic Cloud
Supervisor: Prof. Bryan Gaensler
Contact: Prof. Bryan Gaensler, 556, bgaensler@usyd.edu.au, 9351 6053

Turbulence is the universal process through which bulk flows are converted into heat via viscous eddies and random motions. In the everyday world, turbulence appears in solar flares, weather patterns, aerodynamics and human blood flow. In the Milky Way, turbulence manifests itself through random fluctuations in gas density and magnetic field strength on scales of light years, but the origin of this turbulence is unknown.

Recent measurements of radio polarisation have revealed similar turbulent behaviour in the nearest galaxy to our own, the Large Magellanic Cloud (LMC). This galaxy provides a unique opportunity to study interstellar turbulence in a region at known distance and of low optical extinction. In this project, a student will analyse high-resolution radio observations of galaxies behind the LMC. Using spatially resolved Faraday rotation seen against these sources, we can directly measure the scale and strength of turbulent fluctuations in interstellar gas, and can separate out the contributions due to density and to magnetic fields.

What Does the Universe Look like Through Polaroid Sunglasses?
Supervisors: Prof. Bryan Gaensler (U. Sydney), Dr. Ilana Feain (CSIRO ATNF)
Contact: Prof. Bryan Gaensler, 556, bgaensler@usyd.edu.au, 9351 6053

The overall Universe is fairly isotropic and homogeneous. However, the locations of individual galaxies are not random, but are distributed in a way that shows remarkable structure on very large scales. Some parts of the Universe are almost completely devoid of galaxies, while in other regions galaxies are heavily clustered. This uneven distribution is a direct fossil record of conditions in the early Universe, and is thus a vital diagnostic for understanding the formation of galaxies billions of years ago.

Galaxy catalogues have already revealed a great deal about the large-scale structure of the Universe. However, one piece of information that has not yet been adequately exploited is that some galaxies are strong sources of polarised radio emission (indicating the presence of strong, ordered, magnetic fields), while others are not. Here we thus ask a new question: what does large-scale structure in the Universe look like with polaroid sunglasses on? In this project, a student will analyse existing databases of radio galaxies, and will compute angular correlation functions for both polarised and unpolarised sources drawn from this sample. The results will provide the first ever measurement of large-scale structure in polarisation, and will reveal whether polarised galaxies are distributed in a different way from the overall underlying population. With these data, we can establish whether only certain types of galaxies are polarised, or whether polarisation is a statistical effect that depends on, e.g., viewing angle or luminosity.
How are elliptical galaxies formed?
Supervisors: Prof. Matthew Colless (AAO), Dr. Heath Jones (AAO) and Prof. Elaine Sadler (USyd) Contact: Prof. Elaine Sadler (Room 555)
Email: ems@physics.usyd.edu.au , colless@aao.gov.au & heath@aao.gov.au
Phone: 9351 2622

Astronomers already know a lot about elliptical galaxies, as they are relatively common and straightforward to study. The stars in elliptical galaxies are dis- tributed smoothly and, unlike spiral galaxies, they contain almost no new stars. We also know that these stellar populations are dominated by old, low-mass stars that have been around for almost as long as the universe itself. And we know that ellipticals are found more commonly within the rich clusters of galaxies than in more typical regions of the universe. One of the most remarkable characteristics of elliptical galaxies is that they obey a special relationship (called the Fundamental Plane) between galaxy size, brightness and internal stellar velocity - the origin of this relationship remains something of a mystery, but appears to be linked to the way they are formed and the distribution of dark matter.

Given all this, its easy to see why elliptical galaxies play a central role in guiding our understanding of how galaxies form; the hard part is guring out how all these facts t together into a consistent picture of galaxy formation. The aim of this project is to examine the properties of a very large sample of elliptical galaxies from the recently-completed 6dF Galaxy Survey in order to understand how they form and evolve. The 6dFGS is one of the largest existing datasets for studying galaxy properties, including distances and spectra for more than 120000 galaxies, collected using the AAOs UK Schmidt Telescope over the past 7 years.

From these data we can infer several key galaxy properties such as the age, mass and heavy-element fraction (called metallicity) of the stellar population, and the ratio of luminous matter to dark matter in the galaxy. We can then investigate how age and metallicity a?ect the Fundamental Plane. And be- cause the thousands of galaxies in the 6dFGS delineate galaxy clusters, voids, laments, and large-scale structures in general, we can study trends with local environment in the stellar populations and dynamics of elliptical galaxies. Key questions we want to address are: Exactly how old are the oldest galax- ies, and when do they form their heavy elements? How and why does galaxy formation vary with environment? What is the origin of the Fundamental Plane, and how does it relate to the distribution of dark matter around galaxies? This project is suitable for a student with interests in observational cos- mology and galaxy formation. Data are in hand for immediate use, and opportunities exist to be involved in follow-up observing and conference travel to disseminate results.

Astrophotonics: exploring the behaviour of the photonic lantern
Supervisors: Prof Joss Bland-Hawthorn, Dr John O’Byrne
Contact: John O’Byrne, 568, j.obyrne@physics.usyd.edu.au, 9351 2621

We have been exploring the use of photonic devices, originally developed for telecommunications, to see if there are important applications in astronomy. But telecomm fibres only work in “single mode” whereas astronomical fibres (that are much thicker in order to allow for more light to pass down the fibre) carry many modes because light has many more ways to propagate down the fibre. In order to use exciting single mode devices in conjunction with multimode fibres, we had to invent a remarkable new device called a “photonic lantern.” Here a multimode fibre goes through a taper and splits into a large number of single mode fibres. Just why all of the multimode light finds its way into the single mode fibres is not understood. The photonic lantern has interesting properties that we propose to explore in the lab. Quite apart from exciting new uses in astrophysics, there are possible applications in remote sensing and communications.

Astrophotonics: how to make the night sky go dark
Supervisors: Prof Joss Bland-Hawthorn, Dr John O’Byrne
Contact: Simon Ellis, 323-4, sce@physics.usyd.edu.au, 9351 2621

We are close to completing a revolutionary new technology that allows light from the night sky to pass through an optical fibre before being filtered in a special way. The infrared night sky is perpetually bright, unlike the visible night sky, due to hundreds of bright lines from the atmosphere. Our new filters remove these lines in order render the infrared sky completely dark. This is an age-old problem for astronomers that has only now been solved by our group. In this project, we will investigate the stability and performance of this fibre filter in the lab and at the telescope.

The first miniature spectrograph for astronomy
Supervisors: Prof Joss Bland-Hawthorn, Dr Gordon Robertson
Contact: Gordon Robertson, 562, g.robertson@physics.usyd.edu.au, 9351 2621

Astronomical telescopes are getting larger and larger which means that the cost of their instruments (that analyze the light) are getting prohibitively more expensive. In fact, the cost of a single instrument may even reach $100 M. This is a severe problem with no obvious solution. Recently, we suggested a radical new approach to the problem which is to feed thousands of optical fibres into thousands of individual miniature spectrographs rather than one huge spectrograph. The first of these devices was manufactured this year but has yet to be tested in detail. In this project, we will test and play with the device, and investigate ways to improve the design. If we can demonstrate that it has high efficiency and good behaviour, this will revolutionize our approach to building new astronomical instruments.

The birth of the Local Group
Supervisor: Prof Joss Bland-Hawthorn
Contact: Joss Bland-Hawthorn, jbh@physics.usyd.edu.au, 9351 2621

The Local Group seems very typical of small assemblies of galaxies in the Local Universe. Our own Galaxy is encircled by a large family of dwarf galaxies of which the LMC and the SMC are the most massive. Recent evidence suggests that systems with the mass of the Local Group accrete galaxies in smaller groups rather than individually. If so, at least some of the Galaxy’s dwarfs may have fallen in with the LMC and SMC, such that these were born together in the nearby universe. We will investigate infalling galaxy configurations to see if the LMC-SMC binary pair was once orbitted by one or more low mass galaxies. We will compare our results to the local dwarf data, and we will investigate whether this model can account for recently discovered stellar streams and hypervelocity stars deep within the Galaxy.

Where is the missing dark matter?
Supervisor: Prof Joss Bland-Hawthorn
Contact: Joss Bland-Hawthorn, jbh@physics.usyd.edu.au, 9351 2621

It is now well established that most of the matter in the Universe is “dark” and of a form that is completely mysterious. Most of the dark matter appears to reside in large haloes that surround galaxies. Several groups have used supercomputers to simulate how the Universe evolves in the presence of dark matter, and this led to an extraordinary discovery. There should be about a thousand small dark haloes in the vicinity of our Galaxy. So where are they and how would we detect them? In this entirely theoretical project, I propose to explore a new idea. If enough gas falls into these dark haloes, stars form and we end up with a galaxy. But there is no obvious reason why lots of gas should always find its way into dark haloes; maybe only trace amounts reside in the majority of them. If this is true, we can calculate the physical state of the low density gas to establish what the likely “dark halo” signature might be. This signature could be detectable in the the spectra of distant quasars. As the light from the quasar passes through the dark halo, the diffuse gas absorbs the light at specific frequencies. We will search for the possible existence of nearby dark haloes by looking for the unique signature in on-line archives of quasar spectra.

Where are the stars that were born with the Sun?
Supervisor: Prof Joss Bland-Hawthorn, Torgny Karlsson
Contact: Torgny Karlsson, torgny@physics.usyd.edu.au, 9351 2621

Our Sun was born 4.57 billion years ago in a gas cloud that presumably encircled the Galaxy before collapsing to form stars. It is widely believed that the “Solar Family” may have been made up of 10,000 members, most of them dwarf stars like the Sun. In principle, we can identify members of this family from unique chemical signatures (cf. DNA) that were imprinted into the stellar atmospheres at the time of their birth. But where are they now? Since their birth, these stars have orbited the centre of the Galaxy as many as twenty times. In this project, we will build an accurate dynamical model of the Galaxy, and follow the orbits of many stars born at the same site. We will then explore what it would take to find these stars with modern astronomical instruments.

Galactic winds: are these caused by black holes or supernovae?
Supervisors: Prof Joss Bland-Hawthorn, Dr Zdenka Kuncic
Contact: Joss Bland-Hawthorn, jbh@physics.usyd.edu.au, 9351 2621

Some galaxies exhibit spectacular behaviour in the form of a powerful wind from the central regions. These winds are thought to be produced by the collective behaviour of many thousands of supernovae, although in some cases, a central black hole is also thought to be responsible. An important new survey of these galaxies has begun using the Anglo-Australian Telescope, delivering 3D data on the fast moving gas in these winds. The goal of this project is to extract velocity and mass estimates from the data, and then to derive 3D models of the observations in order to assess just how powerful these winds are, and hence determine whether supernovae or a supermassive black hole is mostly responsible.
Understanding Ionised Gas in High-Velocity Clouds
Supervisor: Dr. Greg Madsen
Contact: Dr. Greg Madsen, 559A, g.madsen@physics.usyd.edu.au, 9036 5106

The space between the stars, or interstellar medium, is filled with vast amounts of gas and dust that fuels the birth of new stars. Most of the gas resides in a thin plane that rotates around a massive black hole at the centre of our Milky Way Galaxy. However, there are some gas clouds, called high-velocity clouds, that do not move with the rest of the gas. The nature and origin of these clouds remain widely debated today. They may be reservoirs of fresh hydrogen falling into our Galaxy for the first time, or may have been ejected by stellar explosions in the Galactic disk. The clouds are a key part of building a picture of how our Galaxy formed and how it will evolve. In this project, you will search for emission lines from ionised gas in high-velocity clouds. You will combine the observations with photoionisation simulations to derive the physical conditions in the clouds, yielding important clues about their composition and origin.

Where are the missing radio supernova remnants?
Supervisor: Dr Tara Murphy, Prof Anne Green
Contact: Tara Murphy, tara@physics.usyd.edu.au

A supernova is a cataclysmic event that occurs at the end of the stellar life-cycle. The initial explosion can be as bright as the entire galaxy that the star resides in and it creates a shock that travels out sweeping up interstellar matter. The result is a radio supernova remnant, which can still be detected thousands of years after the star had died. Statistical studies of supernova rates in other galaxies suggest that there should be many more supernova remnants in our own Galaxy than we have currently detected. This is well established as the ’missing supernova’ problem. Is there something wrong with our understanding of supernova rates? Or are there many more supernova remnants in our Galaxy which are as yet undiscovered?

One possibility is that there is a population of young, compact supernova remnants that have escaped our detection. In this project you will carry out a comprehensive search for young supernova remnants in our Galaxy. This project will make use of radio data from the recently completed Molonglo Galactic Plane Survey, as well as infrared data from the Midcourse Space Experiment (MSX) telescope. The aim of the project is to solve the missing supernova problem.

Radial Abundance Gradients in Disk Galaxies
Supervisors: Prof. Joss Bland-Hawthorn and Dr. Stuart Ryder (AAO)
Contact: Prof. Joss Bland-Hawthorn (Rooms 323-4), jbh@physics.usyd.edu.au & sdr@aao.gov.au, 9351 2621

Oxygen and iron produced in the cores of stars and released in supernova explosions provide fossil records of a galaxy’s evolution state a few million years, and a billion years ago, respectively. We have used the Gemini South 8m telescope and its multi-object spectrograph to obtain data which reveals how the amount of oxygen produced by massive stars changes with distance from the centres of 6 spiral galaxies. Your role will be to process these data and measure the oxygen gradients, which by comparing with existing data on iron gradients in these same galaxies will reveal the star formation history of each one, and help us understand how these galaxies got to be the way they are.

Modelling of the evolution of radio galaxies
Supervisors: Elaine Sadler, Qinghuan Luo, & Mike Wheatland
Contact: Elaine Sadler, 555, ems@physics.usyd.edu.au, 9351 2622

Radio galaxies are generally classified as FR I and FR II, corresponding to low- and high-luminosity galaxies, respectively. The well-accepted model for radio galaxies is a pair of relativistic jets emanating from a central black hole. The FR I and FR II jets have very different morphologies, with the former characterized by the bright regions near the core and the latter by hot spots at the end of the jets. The radio emission is believed to be due to synchrotron radiation by relativistic particles accelerated in the jets. The radio sources are thought to evolve as emitting particles lose energy as the jets propagate away from their cores. How these two classes of sources evolve is a central issue in the study of radio galaxies. Generally, the luminosity of radio sources decreases as their projected linear size increases. Thus, the evolution of radio sources can be characterized by the power-size track. This project will involve analytical modeling of radio emission from relativistic jets, focusing on prediction of radio power as a function of the source size. The project will also involve numerical simulation of power-size tracks for both FR I and FR II sources and tests of the model against observations. Spectroscopic studies of radio galaxies and quasars
Supervisors: Elaine Sadler, Scott Croom, Helen Johnston
Contact: Elaine Sadler, 555, ems@physics.usyd.edu.au, 9351 2622

Radio galaxies and quasars are believed to be two manifestations of the same physical process: the accretion of gas onto a supermassive black hole at the centre of a galaxy. Optical spectra of these objects can help us learn how they are related, and what events might trigger such an energetic outburst from a galaxy’s centre. We will offer one or more projects in this general area, and would be happy to talk to interested students.

Galactic Paleontology with Metal Poor Stars
Supervisors: A/Prof Peter Tuthill, Prof Tim Bedding, Dr Mike Ireland
Contact: Peter Tuthill, 566, p.tuthill@physics.usyd.edu.au, 9351 3679

Ultra metal-poor stars are the living fossils of the stellar kingdom. Although elements heavier than Helium only make up a tiny fraction of any star, they have a profound effect on the stellar structure. Consequently stars born when the universe was substantially younger, before heavy elements were formed, should stand out from the crowd exhibiting dramatically different physical and thermal structure – or so the theoretical models tell us. Because these fossil stars are rare and far from Earth, nobody has ever been able to examine one in detail. Until now. Your job in this project will put these stars under the microscope using the most powerful imaging arrays ever built: The Sydney University Stellar Interferometer and the CHARA array in Southern California. In making the first accurate measurements of the basic properties of metal-poor stars, you will determine whether these exotic objects are indeed as weird as theorists predict. The project then takes direct aim at one of the key questions in cosmology: the lithium abundance of very old stars is significantly lower than Big-Bang nucleosynthesis predicts. Where is the missing Lithium hiding, or is this a chink in the armour for Big-Bang cosmology?

Getting to know the Neighbors: High precision astrophysics in the Pleiades and Hyades Supervisors: Dr Michael Ireland, A/Prof Peter Tuthill
Contact: Michael Ireland, 554, m.ireland@physics.usyd.edu.au, 9036 6518

Precision measurement lies at the heart of physics, yet the distance scale to some of the nearest star clusters (and thence outwards to the universe) has been notoriously difficult to pin down. In this project, you will bring the extraordinary new power of optical interferometry with the CHARA array in California to finally nail this problem. By observing binary star systems at unprecedented resolution, you will match the precise orbital data with radial velocities and therefore obtain a completely model-independent, high precision distance to the crucial Pleiades and Hyades star clusters. The controversy in the distances to these clusters, which are key laboratories for a range of stellar physics, clouds our understanding of basic stellar evolution and even the cosmological distance scale itself.

Detecting close Exoplanets in young southern stars
Supervisors: A/Prof Peter Tuthill, Dr Michael Ireland
Contact: Peter Tuthill, 566, p.tuthill@physics.usyd.edu.au, 9351 3679

Methods of detecting planets by direct imaging have produced only a small handful of controversial discoveries (as opposed to the hundreds of planets found with indirect methods such as radial velocity searches). One of the main reasons for this is that conventional technology, such as an Adaptive Optics Coronagraph, is only sensitive to planets at large separations from their host star: much larger than seen in our own solar system for example. With this project, you will use a new high-resolution imaging technique which focuses on imaging planets where they are expected to be, in close Jupiter or Saturn-like orbits around young host stars in the constellation of Hydra. This project has been awarded 2.5 nights of observing time at the European VLT telescope in Chile. No other technique has had the power to probe the rich southern skies for planets to this level of precision before, making this an area ripe for new discoveries.

Building a Robotic Eye for SUSI: Automated Sensitive Infrared All-Sky Monitoring Supervisors: Dr Michael Ireland
Dr Peter Tuthill
Contact: Michael Ireland, 554, m.ireland@physics.usyd.edu.au, 9036 6518

The Astrophysical Imaging group are robotizing the SUSI array in Narrabri, northwestern NSW. The first steps towards remote operation have already been made, with full automation of the array planned, making it possible to undertake larger astrophysics projects focusing on associated groups of stars rather than individual stars. Although SUSI has always been designed to operate robotically for periods of time, with many dozens of sensors and actuators feeding into a distributed computer network, a live astronomer has always been required to determine if the sky is clear, and to choose what target to observe. In this project, you will develop an all-sky monitoring system that analyzes in real time the apparent brightness of 100 of the brightest stars and makes a decision on whether to open SUSI’s siderostats. Data gathered by this continuously operating camera will also be used to measure the light curve of the bright but neglected M giant star gamma Crucis, placing it clearly within the context of the well-studied M giants in the large Magellanic cloud.

Galactic big game hunting: hot massive stars and supergiants
Supervisors: Dr Gordon Robertson, A/Prof Peter Tuthill, Dr Mike Ireland
Contact: Gordon Robertson, 566, G.Robertson@physics.usyd.edu.au, 9351 2825

In the stellar eco-system, the hot massive luminous stars at the top dominate the galaxy. Exceeding our own sun by factors of five in temperature, fifty in mass, and fifty-thousand in luminosity, these T-Rex’s of the stellar kingdom dominate many aspects of the physics of the galaxy, despite being outnumbered thousands to one by more normal stars. When we look at a distant galaxy, the light we see mostly comes from a handful of these overachievers, outshining the teeming multitudes of low-mass stars. Massive stars exhibit a range of fascinating physics not seen elsewhere, driving intense stellar winds and ending their lives in cataclysmic supernova explosions. However these rare and exotic stars have proved very difficult to study because there are none close enough with well-characterized basic properties to get a strong handle on the physics. Your job in this project will be to make some of the first precise mass measurements of a range of high-mass stars. You will use data from the SUSI array operated by the School of Physics, and the CHARA array in Southern California to image these stars at unprecedented scales of resolution.

The Riddle of the Red Square
Supervisors: Dr Peter Tuthill
Dr Michael Ireland
Contact: Peter Tuthill, Annexe 566, p.tuthill@physics.usyd.edu.au, 9351 3679

The “Red Square” is a spectacular, newly-discovered bipolar nebula (Tuthill et al, Science 2007). Using cuttingedge imaging techniques such as Adaptive Optics and Optical Interferometry implemented at some of the worlds largest observatories (e.g. Keck, Gemini), we have revealed beautiful and startlingly detailed structures. A striking set of rungs crossing the nebula imply the existence of a highly regular series of nested bicones: possibly a relic of previous episodes of eruption or instability in the host star MWC 922 at the heart of the system. What is particularly compelling about this object is the correspondence between the sharp rung structures we see in The Red Square, and the beautiful polar rings now exhibited by the only naked-eye supernova since the invention of the telescope: SN 1987A. The origin of these mysterious rings stands out as one of the foremost unsolved problems in Supernova astronomy, and in the Red Square, we may have found the best example of a candidate progenitor for these structures. For this project, you will unravel the physics of this fascinating target and help design new observing programs for the Keck telescopes (Hawaii) and VLT telescopes (Chile). In revealing the true nature of the enigmatic star MWC 922, we hope to solidify the links between this new nebula and the relic structures around SN 1987A. More information on this object can be found on the web page www.physics.usyd.edu.au/∼gekko
Honours projects – Biophysics 32

Research Projects in Biophysics

Simulating protein unfolding at high temperatures
Supervisor: Serdar Kuyucak
Contact: Serdar Kuyucak, 9036 5306, serdar@physics.usyd.edu.au

Proteins are produced in a string form in cells and fold to their 3-dimensional native states within seconds. Understanding how this happens is one the most important problems in biophysics today. While it is still beyond our reach to simulate the folding process in the native environment of a cell, we can learn from the reverse process of unfolding by speeding it up using higher temperatures than the body temperature. The project involves molecular dynamics simulations of some functionally important proteins at several different temperatures and analysing their structural properties to assess the degree of unfolding. Applied Physics group carries out experimental studies of protein unfolding at high temperatures. So it may be possible to combine the simulation studies with experimental ones.

Unfolding proteins via steering
Supervisor: Serdar Kuyucak
Contact: Serdar Kuyucak, 9036 5306, serdar@physics.usyd.edu.au

A second way to speed up unfolding of proteins (see the above project) is to fix one end of the polypeptide chain and apply a force on the other. This is realized in labs using optical tweezers and atomic force microscopy. This process can also be simulated on computers using steered molecular dynamics (SMD) with harmonic pulling forces. The work done on the protein, and hence the free energy change during unfolding can be calculated using Jarzysnki’s equality. The project involves molecular dynamics simulations of some simple proteins subjected to harmonic pulling forces, and calculating the free energy change during unfolding, which will be contrasted with the structural changes in the protein. An interesting application of this method is studying stretchiness of fibrin via SMD. Fibrin is a protein that helps blood clotting. Recent atomic force microscopy experiments suggest that its stretchiness, which is crucial for blood clotting, may arise from its ease of unfolding. SMD simulations of fibrin would provide a quantitative understanding of the relationship between its stretchiness and unfolding.

Developing drugs from toxins
Supervisor: Serdar Kuyucak
Contact: Serdar Kuyucak, 9036 5306, serdar@physics.usyd.edu.au

Many toxins bind to ion channels affecting their normal operation. Because of their high affinity and specificity, toxins provide ideal leads for developing drugs that target diseases caused by dysfunctional ion channels. At present this search is mostly carried out on a trial and error basis, which is not very efficient. A better understanding of the toxin-channel interactions would lead to a more rational design of drugs from toxins. In this project you will study the binding of conotoxins to potassium channels using simulation methods such as molecular dynamics and docking. Conotoxins are peptides obtained from the venom of marine snails, and some of them have a high affinity for potassium channels. The aim of the project is to find the key residues involved in the binding and study their mutations to see if more potent versions of conotoxins with higher affinity can be developed.

Ion permeation and selectivity in carbon nanotubes
Supervisor: Serdar Kuyucak
Contact: Serdar Kuyucak, 9036 5306, serdar@physics.usyd.edu.au

Carbon nanotubes have many potential applications in biotechnology, medicine, electronics and materials science. An interesting question that may have important ramifications in biotechnology and medicine is whether they can be made to function like ion channels. The project will investigate the permeation properties of carbon nanotubes using molecular dynamics simulations. Steered MD simulations and/or umbrella sampling method will be used to calculate the free energy profiles of ions across a nanotube. Issues to be addressed include: dependence of ion conduction rate on the radius and length of the nanotube, and modification of the nanotube structure by implanting charged residues so as to make it selective to a particular type of ion.

Research Projects in Complex Systems
For convenience, Complex Systems projects are grouped according to the main areas of research listed in the Overview of Research Areas above.
Brain Dynamics and Computational Neuroscience

Sleep Dynamics
Supervisor: Prof. Peter Robinson, Cosupervisors: Assoc. Prof. Naomi Rogers, Faculty of Medicine; Dr Jong Won Kim
Contact: Prof P. A. Robinson, Rm 384 (A29), 9351 3779, robinson@physics.usyd.edu.au

No-one knows exactly why we sleep. In part, sleep onset is governed by a balance between driving by the day-night (circadian) cycle, and the need to remove metabolic byproducts that have built up during the day. This project will extend and test a nonlinear model we have developed for these processes and their action on the brain in order to better understand the dynamics of the sleep cycle, and its disorders, including effects like jetlag, sleep deprivation, alertness prediction and monitoring, and chaotic sleep dynamics.

Network Dynamics and Stability
Supervisor: Prof P. A. Robinson
Contact: Prof P. A. Robinson, Rm 384 (A29), 9351 3779, robinson@physics.usyd.edu.au

Various levels of the brain are interconnected in a hierarchical manner, with tightly interconnected local regions more loosely connected to one another into larger assemblies, which are in turn more loosely connected still. Our initial work shows that this pattern of connectivity enables improved brain stability, more “agile” adjustment to changing inputs, and more efficient communication between regions. This project will involve analyzing the structural and dynamic interconnections of brain regions using models that we have developed, studying stability of synchronization of neural oscillators when hierarchically connected, and determining the consequences for brain dynamics. Comparisons with recently emerging experimental work on brain networks will be pursued, as will theoretical connections with neural field theory.

Neurochronometry
Supervisors: Prof. Peter Robinson and Dr Chris Rennie
Contact: Prof P. A. Robinson, Rm 384 (A29), 9351 3779, robinson@physics.usyd.edu.au

The brain has a prominent 10 Hz resonance in its electrical activity. Despite being discovered in the 1920s, the function of this alpha resonance is still controversial. Recent work has shown that it is produced by resonances in loops connecting the cerebral cortex to deeper structures in the brain. Some findings also relate it to information processing speed and other cognitive functions. This project will use data from the Brain Resource International Database (of multiple brain measures on over 6000 subjects) to test some of these hypotheses with high statistical power and using nonlinear diagnostics, then relate them to quantitative brain-dynamic theory for the first time.

Bursting Neurons
Supervisor: Prof. Peter Robinson
Contact: Prof. P. A. Robinson Rm 384 (A29), 9351 3779, robinson@physics.usyd.edu.au

Many neurons fire in response to applied currents in ways that do not depend on their history. However, others have calcium-mediated ion channels that pass only transient currents in response to stimulation, then inactivate. These channels must then be deinactivated before they can respond again. This behavior is involved in some bursts and oscillations seen in the brain, including during epileptic seizures and deep sleep. The aim of this project is to incorporate T channels into neural field theory to enable their contribution to large-scale brain dynamics to be studied systematically. This will involve developing a suitably parametrized model of the calcium currents, starting from basic biophysical equations for these ion channels.

Prediction of Epileptic Seizure using EEG signals
Supervisors: Dr J. W. Kim and Prof P. A. Robinson
Contact: Dr J. W. Kim, Rm 386 (A29), 9351 3779, jwkim@physics.usyd.edu.au

Epileptic seizure is characterized by synchronized, paroxysmal, and excessive discharges of neural population, which affects up to 5% of people at some stage of their life span. Prediction of seizure, before it is fully developed, is very important to secure safety of patients and control of seizure. Electroencephalography (EEG) is often used to diagnose and/or characterize seizures. Recently, several tools have been suggested to predict seizures. Despite their many successes, they still need improvement for use in clinical situations. We will thus study and explore seizure EEGs to obtain efficient seizure prediction. Successful results are aimed to present at the International Workshop on Epileptic Seizure Prediction scheduled in 2009 (https://epilepsy.unifreiburg.de/prediction-contest).

Synchronization of Neurons in Brain
Supervisors: Dr J. W. Kim and Prof P. A. Robinson
Contact: Dr J. W. Kim, Rm 386 (A29), 9351 3779, jwkim@physics.usyd.edu.au

Synchrony of neurons in brain has been studied to explore brain diseases such as Parkinson’s and epilepsy, which generally show excessively synchronized behaviors. For example, P.A. Tass modeled the neurons as phase oscillators and suggested several methods to therapeutically desynchronize the neurons. Although he qualitatively described many phenomena successfully, his method still needs some improvement. We thus propose a new method that replaces Tass’s abstract phase-oscillator variables by dynamical variables that can be physiologically measured. We will use a physiology-based brain model to describe the dynamics of these variables. Conditions for abnormal synchrony will be investigated and related to electroencephalography measurements.

Imaging the functioning brain: Temporal delay in BOLD response
Supervisors: Dr Peter Drysdale and Prof P. A. Robinson
Contact: Dr Peter Drysdale, Rm 385, peter@physics.usyd.edu.au

In order to understand the functioning of the brain it is important to be able to measure and image its neural activity changes. Such an imaging technique should be noninvasive: i.e., not involve having to cut into the skull. Active neurons are known to have increased oxygen consumption, and thus regions of increased brain activity show local deoxygenation of their blood supply. In an MRI scanner it is possible to measure this local deoxygenation via the so called Blood Oxygen Level Dependent (BOLD) MRI signal. Thus BOLD measurement is an indirect probe of neural activity and the brain’s functioning. BOLD imaging is very widely used by neuroscientists to understand brain function due to its fine spatial resolution. However, to properly understand the significance of BOLD measurements it is necessary to link the measured BOLD signal to the underlying activity of neurons. This is an area of extremely active research as models of this link between neural activity and BOLD response are necessary to allow better interpretation of studies of brain function based on BOLD imaging.

Recently, we have analyzed a widely used temporal BOLD response model (the Friston-Obata model) and have been developing the first detailed spatial/temporal BOLD response model. Other researchers have proposed an additional time delayed BOLD response to account for inadequancies in the Friston-Obata model. The aim of this project is to explore and analyze numerically and analytically the delayed BOLD response and to estimate bounds for the size of delay effects from existing published experimental data. An extension of the project to include proposing delay terms for the spatial/temporal BOLD response model may be possible if time premits.

How does the brain compute? Distributed dynamical computation in neural circuits Supervisors: Dr Pulin Gong, Prof. Peter Robinson
Contact: Dr Pulin Gong, 374, 9036 9368, email: P.Gong@physics.usyd.edu.au

One of the most fundamental problems about the brain is how it computes. To answer this question, recently we have presented a concept of emergent, distributed dynamical computation in which computation is carried out by interacting, moving brain activity patterns such as waves. The concept can merge dynamics and computation aspects of the brain, which used to have great gaps between each other. The project will involve making further links between dynamics and computation, including studying our current models and models of complex systems.

The dynamical origin of event related potential (ERP)
Supervisors: Dr Pulin Gong, Prof. Peter Robinson, Dr Andrey Nikolaev (RIKEN, Brain Science Institute, Japan), Prof Cees van Leeuwen (RIKEN, Brain Science Institute, Japan)
Contact: Dr Pulin Gong, 374, 9036 9368, email: P.Gong@physics.usyd.edu.au

The origin of event related potentials is being hotly debated between two different views: evoked activity origin and induced activity origin. We will study the origin of ERP from the perspective that the brain may be a kind of non-equilibrium pattern-forming systems. Indeed, the collective patterns such as traveling waves and spiral waves have been found in spontaneous oscillations with 10 Hz. We will study how such spontaneous activity patterns can interact with evoked moving activity patterns with different frequencies, therefore resulting in collective phase shifts. The results of this project will provide a deeper understanding about the mechanism of ERP generation.
Co-evolution of dynamics and structures of complex networks
Supervisors: Dr Pulin Gong, Prof. Peter Robinson
Contact: Dr Pulin Gong, 374, 9036 9368, email: P.Gong@physics.usyd.edu.au

Many networks including natural networks and human-made ones have small world, scale-free structures. We have presented a model with dynamical units to interpret how systems with dynamical behaviors can selforganize to such complex networks. In this project, we will study the physics of the dynamical evolution process, and determine how dynamics can evolve to a kind of edge of chaos behavior, meanwhile the structures reaches small-world networks. We will be particularly interested in the underlying physics such as phase transition and dynamical percolation of the evolving process.

Undecidable dynamics of complex systems and its application in the brain
Supervisors: Dr Pulin Gong, Prof. Peter Robinson
Contact: Dr Pulin Gong, 374, 9036 9368, email: P.Gong@physics.usyd.edu.au

Undecidable dynamics is a kind of dynamics that is more complex than chaos, and it has some interesting properties such as the power-law separations of different trajectories over time. The dynamics has been found in Turing machine that is able to do universal computation. However, it has been rarely studied in the field of dynamical systems. We will study the other aspects of undecidable dynamics by treating Turing machine as a dynamical system. Moreover, the project will reveal the possible general relationship between undecidable dynamics and universality properties of complex systems. The results of this project will be applied to brain dynamics.

Scanning space by time: dynamics of eye movements
Supervisors: Dr Pulin Gong, Prof. Peter Robinson, Dr. Chie Nakatani (RIKEN, Brain Science Institute, Japan), Prof. Cees van Leeuwen (RIKEN, Brain Science Institute, Japan)
Contact: Dr Pulin Gong, 374, 9036 9368, email: P.Gong@physics.usyd.edu.au

When we see an image, our eyes rapidly shift from one part to another, leading to dynamical visual streams which enter our brain. The project will use natural scenes as stimuli to see how our eye movements scan them. Our initial results show that instead of being a fully random process, eye movements are a kind of Levy flight process with long-range temporal coherence. This project will involve data analysis and modeling of Levy flight aspects of viewing natural scenes, studying what the functional implications of such process and whether it is optimal for visual searching.

Plasma Theory and Applications
Complex Plasmas
Plasma screening of a charged dust particle near electrode
Supervisors: Dr. Roman Kompaneets and Prof. Sergey Vladimirov
Contact: Prof. Sergey Vladimirov, Rm 382, 9351 5770, S.Vladimirov@physics.usyd.edu.au

The dynamics and self-organization of charged dust particles embedded in a plasma (e.g., formation of dust crystals) is primarily governed by their mutual electrostatic interaction. This interaction is not simply the Coulomb interaction — in fact, the Coulomb potential of a dust particle embedded in a plasma is screened by free ions and electrons. In an isotropic plasma, the resulting screened potential is generally of the Debye form. However, in most laboratory complex plasmas experiments the charged dust particles are levitated in the near-electrode region where the plasma is strongly anisotropic due to the presence of a suprathermal ion flow towards the electrode. In this case, the isotropic Debye potential is not applicable. This project aims to theoretically investigate what the screened potential is in this most frequently encountered case. The theoretical results could be compared with existing direct measurements.

Ionization instabilities in complex plasmas
Supervisors: Dr. Roman Kompaneets and Prof. Sergey Vladimirov
Contact: Prof. Sergey Vladimirov, Rm 382, 9351 5770, S.Vladimirov@physics.usyd.edu.au

Complex plasmas are open systems because dust particles collect free ions and electrons created by ionization. One of the fundamental questions addressing the role of the openness of complex plasmas in different self-organization processes (formation of clumps, voids, vortices, etc.) is whether and when a balance between plasma creation due to ionization and plasma loss due to absorption on dust particles can occur and be stable. This project aims to theoretically address this question within the framework of the fluid approach. Ion-acoustic surface modes in the near-electrode region
Supervisors: Dr. Roman Kompaneets and Prof. Sergey Vladimirov
Contact: Prof. Sergey Vladimirov, Rm 382, 9351 5770, S.Vladimirov@physics.usyd.edu.au

Laboratory and industrial plasmas are usually bounded by walls/electrodes. The near-electrode region is usually characterized by plasma non-neutrality and suprathermal ion flow towards the electrode. This project aims to theoretically investigate the properties of ion-acoustic plasma surface modes propagating along the electrode in the near-electrode region. Apart from being of fundamental interest to plasma physics, this project may have important applications. For example, the problem of stability of the near-electrode region with respect to generation of ion-acoustic surface modes is important for various plasma technologies (e.g., plasma processing, sputtering and deposition technologies) because the instability can affect significantly the properties of ions flowing through the near-electrode region towards the electrode/sample.

Stability of mobility-limited ion flow in a weakly-ionized plasma
Supervisors: Dr. Roman Kompaneets and Prof. Sergey Vladimirov
Contact: Prof. Sergey Vladimirov, Rm 382, 9351 5770, S.Vladimirov@physics.usyd.edu.au

A mobility-limited ion flow in a weakly-ionized plasma is a flow of the ion component with respect to the neutral background, which is driven by an external electric field and whose velocity is determined by the balance of the electric field force and neutral friction. Such flows are ubiquitous in laboratory and industrial plasmas. The presence of such a flow modifies significantly the properties of the ion-acoustic collective plasma modes and, in particular, may cause instability. This project aims to theoretically investigate, on the basis of the kinetic approach, how the ion-acoustic modes are changed and when the instability occurs.

Group theory for Coulomb clusters in a complex plasma
Supervisors: Prof. Sergey Vladimirov, Dr Alex Samarian
Contact: Prof. Sergey Vladimirov, 9351 5770, S.Vladimirov@physics.usyd.edu.au

Finite Coulomb clusters are systems consisting of a small number of charged particles confined by an external field. Experimentally, Coulomb clusters have been successfully realised in systems where a finite number of electrons and ions have been localised in traps, created by artificial confining potentials. Examples are the radiofrequency trapping of electrons and ions in a plasma, heavy ion storage rings, electrons on a liquid helium surface, and electrons in quantum dots. Novel types of finite Coulomb clusters can be formed in complex plasma. In this case Coulomb clusters can be think of as a collection of very, very small dust particles, which are a hundredth of a millimeter in diameter, trapped by a parabolic electric potential well. Because of their unique physical properties due to their small size, along with the relative ease in the analysis of the individual particles, Coulomb clusters have been a hot topic of theoretical and experimental studies in complex plasma physics. Currently there is a strong interest in the structure and symmetries of these Coulomb clusters. And if successful, this knowledge can be used in a wide range of applications from everyday life to specific industry needs in the future. Project involves analysing and modelling of Coulomb clusters as well as cluster modes of particle oscillations on the basis of the group theory.

Anomalous diffusion and dynamic chaos of charged particles in low-dimensional structures Supervisors: Dr Alex Samarian, Prof. Sergey Vladimirov
Contact: Dr Alex Samarian, 9351 5959, A.Samarian@physics.usyd.edu.au

For various complex systems, such as colloidal suspensions, complex quasi-2D plasmas, sandpile models, turbulent flows, etc., the diffusion exhibits anomalous character associated with nontrivial topology of the phase space of the system and spatiotemporal correlations. The main manifestation of the anomalous diffusion is in the nonlinear time dependence of the mean square displacement, in contrast to the linear character for the normal diffusion process. Complex plasmas provide a natural example of a system of strongly interacting particles with an often anomalous character of the dust particle diffusion. This project is to investigate, by experiment and modelling, the character of the diffusion in complex plasma structures consisting of finite number of particles. Preliminary studies indicate that the character is anomalous exhibiting such peculiarities as Levy flights. Topology of phase portraits will be analysed to reveal the nature of the developed dynamic chaos and its important characteristics, the diffusion, in low-dimensional structures of charged particles.

Fractional and non-Hamiltonian dynamics of particles in a plasma
Supervisors: Prof. Sergey Vladimirov, Dr Alex Samarian
Contact: Prof. Sergey Vladimirov, 9351 5770, S.Vladimirov@physics.usyd.edu.au

A nonlinear dynamic system near the point of marginal stability exhibits a range of intriguing phenomena such as critical behaviour and developed dynamical chaos. Fractional derivatives have been shown to provide an accurate description of the chaotic dynamics which gives rise to fractal phase space volumes such as the wellstudied stochastic layer in a periodically forced systems. Fractional dynamics has proven to be a useful tool for understanding the complexity associated with the most fundamental interactions in quantum field theory. A reformulation of Hamiltonian dynamics using fractional derivatives encompasses a wider class of systems than the conventional Hamiltonian. The project involves analytical study complemented by numerical simulations. The set to be investigated includes nonlinear equations of motion of a charged plasma particles. The values of the parameters describing chaotic dynamics of particles are expected to be obtained. The developed theory is expected to provide insights to the nature of non-Hamiltonian phenomena, the topic of the recent forefront research.

Hall instability in a magnetized dusty plasma
Supervisors: Prof. Sergey Vladimirov, Dr Birendra Pandey
Contact: Prof. Sergey Vladimirov, 9351 5770, S.Vladimirov@physics.usyd.edu.au

The simplest case of a magnetized complex (dusty) plasma, in which the ion and electron inertia can be ignored and dust can be considered stationary, is subject to the Hall instability in the presence of plasma inhomogeneities. Since the Hall drift is non-dissipative in nature, such an instability will cause the transfer of energy from the large scale to the small scale until finally dissipation takes over. This instability has been proposed as a viable mechanism for the magnetic energy redistribution in the neutron star crusts. However, unlike the neutron star where convective motion is presumably absent in the crystallized crust, in a dusty plasma the convection of the plasma fluid can be neglected in the zero inertia limit. If the grain charge fluctuates due to the presence of the density inhomogeneities, then the Hall instability is considerably modified. This will affect the growth rate of the instability. It is not known whether the charge fluctuation will cause the increase or decrease in the growth of the fluctuations. Clearly, charge dynamics will have important implications for the onset and saturation of turbulence in a complex dusty medium. The obtained knowledge can be used in a wide range of space and astrophysical applications such as dust molecular clouds, star forming regions, etc.
Plasma Nanoscience, Nanotechnology, Surface Science and Plasma Applications
Self-assembled nanodevices: how to match the US$1 Trillion demand and sub-10 nm supply Supervisor: Hon. Prof Kostya (Ken) Ostrikov, Co-supervisor: Dr Igor Levchenko; project may involve other staff and external collaborators nominated by the supervisors.
Contact: Hon. Prof Kostya (Ken) Ostrikov, email: K.Ostrikov@physics.usyd.edu.au

The global present-day demand of the society driven by a synergy of Information Technology, Biotechnology, and Nanotechnology (a “Golden Triangle” of the New Industrial Revolution) for better, faster, and cheaper computers demands that by the year 2012, which is just a few years away from now, global sales in semiconductor-based integrated circuitry products reach US$ 1 Trillion. This requirement can only be met if the cost per electronic function drops with a steady rate and reaches tiny fractions of a cent keeping the cost of a microchip about the same. In other words, the society requests unprecedented compactification of ever-shrinking in size (down to 10 nm and below) logic elements, which cannot be achieved by any existing means used by present-day semiconductor industry. The only way to solve this global problem is to create the as yet elusive self-organized nanodevices. This project is to explore, via advanced numerical simulations, various possibilities of creation of elements of such nanodevices on plasma exposed surfaces.

Third generation photovoltaics: quantum dots put the ‘new’ in re‘new’wable energy Supervisor: Hon. Prof Kostya (Ken) Ostrikov, Co-supervisors: Dr Joe Khachan; project may involve other staff and external collaborators nominated by the supervisors
Contact: Hon. Prof Kostya (Ken) Ostrikov, email: K.Ostrikov@physics.usyd.edu.au

Third generation photovoltaic devices have been the subject of intense research efforts due to increasing interest in cost effective, renewable green energy. One of the main hurdles in the widespread utilization of solar energy is the inefficiency of typical commercially available solar cells. The incorporation of nanostructured materials such as quantum dots in these devices results in increased efficiency, for example, silicon tandem solar cells and intermediate band solar cells (IBSC) incorporating quantum dots have limiting efficiencies higher than 50% as opposed to conventional commercially available solar cell efficiencies of approx. 10%. There are a number of requirements for quantum dots intended for solar cell application; namely the uniformity of dot size (ultrasmall), periodic spacing, and the ability to be fabricated in dense patterns. Additionally in some applications it is advantageous to use wide-bandgap materials, such as GaxAs1−x or SixC1−x which are comprised of more than one element. The existing techniques fail to satisfy all these conditions as well as being able to precisely control the formation of binary (or more complicated) materials, where densities and sizes of nanocrystals as well as elemental ratios x are the primary controls of photoluminescent properties. This project aims to find and justify appropriate plasma process conditions when the nanostructured films can be grown to satisfy some of the above major requirements. It can be tailored to a person with either experimental or theoretical/computational preferences or a combination thereof.

Nanoislanded metal catalyst films via plasma-enhanced magnetron sputtering Supervisors: Hon. Prof Kostya (Ken) Ostrikov, Co-supervisors: Dr Joe Khachan; project may involve other staff and external collaborators nominated by the supervisors
Contact: Hon. Prof Kostya (Ken) Ostrikov, email: K.Ostrikov@physics.usyd.edu.au

The unique electronic and mechanical properties of carbon nanotubes (CNTs) are related to their diameter and chirality. Given that high aspect ratio nanostructures as CNTs constitute the building blocks of many nanoelectronic devices, including as nonvolatile random access memories, field-effect transistors and nanotube circuits in logic gates, there is a pressing demand for a robust and reliable method to control CNT structure. In most existing fabrication techniques such as chemical vapor deposition (CVD) and plasma-enhanced CVD (PECVD), transition metal catalyst nanoparticles (NPs) are required in order to initiate CNT growth. There is a correlation between the size of catalyst particles and the resulting diameter of the single-walled carbon nanotubes (SWCNTs). Such NPs are commonly formed by thermal fragmentation of a pre-deposited ultrathin continuous film, which unfortunately shows poor controllability of nanoisland size. This project is to demonstrate that by using plasma-assisted pulsed magnetron sputtering and varying arrangement of the sputtering targets and the substrate positioning and other parameters, it is possible to generate arrays of metal nanoislands that satisfy the main requirements for the nanotube growth. The ultimate aim of this project is to develop a method of preparing metal nanoparticles with a narrow range of preset, ultra-small diameters with high surface coverages, suitable for a variety of applications, not limited to carbon nanotube growth.

Plasma-aided nanoassembly: one step closer via numerical simulation, experiments or a combination thereof
Supervisor: Hon. Prof Kostya (Ken) Ostrikov Co-supervisors: Dr Igor Levchenko; Prof A. B. Murphy (CSIRO Industrial Physics); project may involve other staff and external collaborators nominated by the supervisors Contact: Hon. Prof. Prof Kostya (Ken) Ostrikov, email: K.Ostrikov@physics.usyd.edu.au

The aim of this project is to develop the physical principles of nano-scale assembly processes in laboratory, space and astrophysical plasmas. There is a pressing demand to develop novel approaches for tailoring the plasma-grown building blocks in various self-organization processes at nanoscales. Examples of applications of such approaches include but are not limited to plasma-aided nanofabrication of nanodevices, nanostructured films, nanoassemblies with intricate architecture and exotic properties, deposition of ordered nanoparticle arrays on nanopatterned solids, and origin and self-organization of dusty matter in the Universe. The project will contribute to elucidation of fundamentals of the multi-scale dynamic processes in various plasma-solid systems in laboratory and space. This will ultimately lead to the improvement of the existing and the emergence of new techniques for plasma-aided fabrication of new nano- and biomaterials and electronic/photonic devices, as well as global understanding of nanoassembly processes in the Universe. The expected outcomes are highly relevant for the nano-materials and optoelectronic technologies, rapidly emerging areas of high-tech industries worldwide.

Origin of symmetry and self-organization in sub-nano large-scale patterns
Supervisors: Dr Igor Levchenko; Hon. Prof Kostya (Ken) Ostrikov; project may involve other staff and external collaborators nominated by the supervisors
Contact: Hon. Prof Kostya (Ken) Ostrikov, email: K.Ostrikov@physics.usyd.edu.au

The behavior of ultra-nanosized objects, that consist of just several atoms, determine in a great extend the further development of the whole ensemble; that is why it is so important to set a proper control and direct the system to the “proper” way at the ultra-nano stage. This project is aimed to the development of the model and simulation code able to describe the origin of order and symmetry in the ensembles of sub-nano Quantum Dots Nuclei (QDN) consisting of 10..100 atoms. At this stage, the QDNs still can move about the surface, yet not so fast as the adatoms. The QDNs stage should be modeled in terms of “affected diffusion”, i.e. QDNs diffusion that causes origination of the long-scale order. The diffusion mobility of the QDNs is relatively large, this outlines a set of physical phenomena involved: stochastic diffusion of sub-nano QDNs consisting of 5..20 atoms, interchange of energy between the sub-nano QDNs via evaporating/attaching adatoms, diffusion of sub-nano QDNs by the surface strain, diffusion of sub-nano QDNs by non-uniform growth in the adatom field. We plan to find several triggering keys that enables as to start an effective self-ordering process in the QDN ensemble, and get eventually a perfect self-ordered pattern.

Self-organized large-scale Quantum Dot patterns
Supervisors: Hon. Prof Kostya (Ken) Ostrikov, Dr Igor Levchenko; project may involve other staff and external collaborators nominated by the supervisors
Contact: Hon. Prof Kostya (Ken) Ostrikov, email: K.Ostrikov@physics.usyd.edu.au
The project is aimed to the development of the model and simulation code able to describe the development of order and symmetry in the large (10^10 nano-objects) ensemble of Quantum Dots (QDs) which consist of 100...10000 atoms. At this stage of the ordering, the QDs cannot move directly about the surface, and their displacement is caused by the following phenomena: displacement by the surface strain, displacement by nonuniform growth in the non-uniform adatom field, displacement by reshaping under affect of surface strain, and displacement by the reshaping under affect of electric field. We are planning to find, by the large-scale numerical simulation, the conditions for the effective self-assembly that is a versatile present-day nanotool. Specifically, we plan to investigate an influence of the key parameters on the self-ordering process, determine the range of the effectiveness, and eventually build an “own” self-ordered pattern. This project can be ideally suited for someone particularly interested in visualizing and animating physical phenomena.

Plasma-assisted fabrication of nanostructured hydroxyapatite bioceramics for applications in orthopaedics and dentistry
Supervisor: Hon. Prof Kostya (Ken) Ostrikov, Co-supervisor: Dr Igor Levchenko; project may involve other staff and external collaborators nominated by the supervisors
Contact: Hon. Prof Kostya (Ken) Ostrikov, email: K.Ostrikov@physics.usyd.edu.au

Hydroxyapatite (HA) coatings find numerous applications in orthopaedics and dentistry owing to their excellent ability to promote stronger implant fixation and faster bone tissue ingrowth and remodelling. Thermal plasma spray and other plasma-assisted techniques have recently been used to synthesize various calcium phosphatebased bioceramics. However, the existing techniques fall short to meet the coating requirements imposed by biomedical industry. Recently, an advanced plasma-assisted concurrent sputtering deposition technique of high-performance biocompatible HA coatings on Ti6Al4V implant alloy has been proposed and tested. The plasma-assisted Rf magnetron co-sputtering deposition method allows one to simultaneously achieve most of the desired attributes of the biomimetic material and overcome the problems peculiar to other existing methods. The project will reveal the optimal conditions when the plasma-generated reactive species can be deposited on the surface and thus take part in the bioceramic fabrication process.

Controlled synthesis of ion-focusing nanostructures: improving predictability Supervisors: Hon. Prof Kostya (Ken) Ostrikov, Dr Igor Levchenko; project may involve other staff and external collaborators nominated by the supervisors
Contact: Hon. Prof Kostya (Ken) Ostrikov, email: K.Ostrikov@physics.usyd.edu.au

Plasma-aided nanofabrication is an emerging research area at the cutting edge of the physics of plasmas and gas discharges, nanoscience and nanotechnology, materials science and engineering, and structural chemistry [Rev. Mod. Phys. 77, 489-511 (2005)]. The existing approaches to fabricating exotic nanostructures and functional nanofilms are mostly process-specific and suffer from cost-inefficient “trial and error practices. One of the reasons is that the ability to control in the plasma phase the generation, transport, deposition, and structural incorporation of the building units of such films and structures, still remains elusive. This project will challenge one of the previously intractable problems of how to manipulate the ionic building units in the non-neutral layer of space charge that separates the plasma and solid surfaces. The major aim of this project is to explore, by means of advanced computer simulation, the microscopic topology of ion fluxes in the vicinity of selected functional nanostructures and the arrangement of adsorbed species into nanopatterns on solid surfaces.

Organic-nanoinorganic composites for new-generation photovoltaic solar cells Supervisors: Dr Igor Levchenko, Hon. Prof Kostya (Ken) Ostrikov; project may involve other staff and external collaborators nominated by the supervisors
Contact: Hon. Prof Kostya (Ken) Ostrikov, email: K.Ostrikov@physics.usyd.edu.au

Photovoltaic nanodevices are of paramount importance worldwide as simple and viable sources of cheap green energy. However, after several tens of years of intense research in the area, we still do not have sufficiently cost-effective and powerful solar cells Polymer/nanotube based solar cells can be a possible solution for the energy problem. These devices demonstrate excellent characteristics; however, methods of their fabrication are still intricate and not reliable. In one traditional technique, carbon nanotubes are produced by an arc discharge, then collected, sorted, purified, functionalized, immersed into polymer matrix, distributed; many more processes involving complex manual manipulations are involved to produce a very dense and perfectly aligned nanotube array in the polymer matrix. In this project, we propose to the student to develop and investigate by an advanced numerical simulation a novel process of polymer/nanotube photovoltaic cell production. A new breakthrough technology should be capable of producing a composite nanotube-based solar cell by a single continuous process which will involve fabrication of ordered arrays of self-assembled single-walled carbon nanotubes, their treatment, activation, functionalization, and making polymer matrix by plasma deposition. The project is ideally suited for a student particularly interested in conducting research in arguably the hottest area of modern nanotechnology.

Nanoscale self-organization in plasmas or uncovering the Nature’s mastery
Supervisors: Hon. Prof Kostya (Ken) Ostrikov, Dr Igor Levchenko; project may involve other staff and external collaborators nominated by the supervisors
Contact: Hon. Prof Kostya (Ken) Ostrikov, email: K.Ostrikov@physics.usyd.edu.au

The two major existing approaches to nanoassembly are based on nanomanipulation of individual building units by external means, such as a sharp tip of a Scanning Tunneling Microscope or via self-assembly of subnanometre building units (such as atoms and simple molecules) into nanometre patterns (self-organization). It is commonly known that 99% of the matter in the Universe is in the plasma state. On the other hand, we are not aware of any extraterrestrial intelligence-driven ”manipulator arms” that assemble solid matter in the Universe, which leaves the only one viable, the self-organization, pathway. The project is to reveal, via numerical modeling, how the Nature’s mastery works in the self-assembly of nanometre-sized dust particles in the Universe and of exotic nanoassemblies in laboratory plasmas.
Space Plasma Physics
Stochastic Depolarization
Supervisors: Prof. Peter Robinson, Prof. Iver Cairns, and Dr Yuriy Tyshetskiy
Contacts: Prof P. Robinson,384, 9351 3779, p.robinson@physics.usyd.edu.au

Random wave growth in turbulent plasmas generates waves that scatter off turbulent fluctuations and must random-walk out of their source region. This leads to extended emission tails that persist long after wave generation ceases. Another expected effect is that each scattering should partly depolarize the radiation. This project will calculate this effect and compare it with polarization observations. The results are expected to give better insight into how radio emissions escape their sources to reach space- and ground-based detectors.

Electromagnetic Strong Turbulence
Supervisors: Prof. Peter Robinson and Prof. Iver Cairns
Contact: Prof. Peter Robinson, 384, 9351 3779, p.robinson@physics.usyd.edu.au

When plasma wave intensities become large, they change the properties of the plasma itself, leading to selffocusing of intense wave packets, which can then collapse to short scales, before dissipating. If such waves are pumped by an energy source, a statistically steady state of strong plasma turbulence can develop, comprising intense packets amid a sea of low level incoherent waves. Turbulence consisting of electrostatic waves has been studied for over 20 years, but electromagnetic strong turbulence (EMST) is little understood. This project would involve exploring the properties of EMST using both analytic techniques and numerical simulations. We have recently developed computer codes to do the first ever 3D simulations of large-scale electromagnetic turbulence, in collaboration with Dr Olaf Skjaeraasen of Oslo, so completely new regimes can be explored for the first time.

Interpretation and Observation of Solar Radio Emissions
Supervisors: Dr Vasili Lobzin and Profs Iver Cairns and Peter Robinson
Contacts: Vasili Lobzin or Iver Cairns, 385 and 383, v.lobzin or i.cairns@physics.usyd.edu.au

Recently we have performed breakthrough analyses of type II and III solar radio data, allowing the first direct determinations of the density profile in the solar corona. This project will extend these analyses to investigate the fine structures and burstiness of type II emission using novel analyses, to extract the magnetic field profile and decorrelation length of the magnetic field, and then to compare the observational results with theoretical ideas. The project will involve data from Australian, German, and Russian radiotelescopes.

Using modern methods of image processing for automatic recognition of solar radio bursts Supervisors: Dr Vasili Lobzin, Prof Iver Cairns, Prof Peter Robinson
Contact: Dr Vasili Lobzin, 385, 9351 3810, v.lobzin@physics.usyd.edu.au

Space Weather means changes in the space environment, beginning from the Sun surface to the Earth and further beyond the Earths orbit. Studying Space Weather has already become very important both from scientific and economical point of view. Major space weather events can be rather harmful both to spacecraft and state of human health. They can also disrupt electric power systems, GPS etc. On the other hand, they cause the beautiful auroral lights often seen at the high latitudes. The near-Earth environment changes due to energetic events on the Sun (solar flares etc.), which are usually accompanied by big enhancements in the solar radio emission solar radio bursts. These bursts can be detected by radio spectrographs, analyzed in real time, and used to call an alert. Dynamic spectra can be considered as two-dimensional signals — intensity versus frequency and time — or gray-scale images. This allows one to use the methods of image processing for analysis and interpretation of the spectra. The aim of the project is to develop and implement methods suitable for automatic recognition and classification of solar radio bursts, as well as for detailed manual analysis of events of particular interest. The data are provided by Learmonth (WA) and Culgoora (NSW) Solar Radio Spectrographs. In close collaboration with experimental teams, the student will be able to perform interesting and practically important space physics research. Some additional useful information can be found at the site of Australian IPS radio and space services (http://www.ips.gov.au, http://www.ips.gov.au/Educational).

Mode Conversion of Auroral Waves
Supervisors: Profs Iver Cairns, Peter Robinson, Jim LaBelle (Dartmouth College, USA), and Craig Kletzing (University of Iowa, USA) and Dr Eun-Hwa Kim (Princeton Plasma Physics Laboratory, USA) Contact: Iver Cairns, 383, 9351 3961, i.cairns@physics.usyd.edu.au

The auroral regions of Earth’s ionosphere contain strong waves driven by the energetic electrons that stimulate the visible aurora. These regions are also strongly magnetized. Profs LaBelle and Kletzing have data from recent NASA-funded rocket flights that cast doubt on the standard model for generation of Langmuir and whistler waves in these regions. This project involves new computer simulations of the linear mode conversion of whistlers into Langmuir waves, and vice versa, at density gradients. It will use an existing numerical simulation code to perform the first simulations of these processes in the strongly magnetized limit, studying the conditions for which mode conversion occurs and its efficiency and characteristics. The results will be compared with the rocket data.

Mode Conversion of Wavepackets of Langmuir waves
Supervisors: Profs Iver Cairns and Peter Robinson and Dr Eun-Hwa Kim (Princeton Plasma Physics Laboratory, USA)
Contact: Iver Cairns, 383, 9351 3961, i.cairns or p.robinson @physics.usyd.edu.au

Theories for solar and interplanetary radio emissions depend sensitively on the radio emission processes assumed. Recently we have made excellent progress on the linear mode conversion of Langmuir waves into radio emission at density gradients in weakly magnetized plasmas. However, this research uses simulations of continuous wave trains whereas real observations show that the Langmuir waves consist of irregular bursts and wavepackets. The frequency spectrum, efficiency, and timing of the radiation are expected to depend significantly on the incoming waves being wavepackets rather than continuous wavetrains. This project involves using an existing simulation code to perform the first studies of mode conversion of Langmuir wavepackets. Predictions will be developed for several solar and interplanetary applications, and the results compared with the predictions for continuous wavetrains and previous work.

New science from NASA’s STEREO spacecraft
Supervisors: Profs Iver Cairns and Peter Robinson
Contact: Iver Cairns, 383, 9351 3961, i.cairns or p.robinson @physics.usyd.edu.au

NASA’s two STEREO spacecraft observe radio emissions generated in the solar corona and interplanetary medium, as well as in situ plasma waves. Multiple unanswered questions exist concerning type II and III radio bursts and the generation of Langmuir and ion sound waves. We have direct access to the STEREO wave data, including a new class of instrument (LWS) whose data have not yet been analyzed. A number of projects are available to address these questions and datasets, ranging from more observational to more theoretical. They include: (1) The first analyses of LWS data for interplanetary plasma waves and comparisons with the Stochastic Growth Theory developed at U. Sydney. (2) Detailed analyses of the statistics and spectral properties of Langmuir wavepackets in type III sources and comparisons with simulations and theory. (3) First calculations of the correlation functions of plaasma waves in the solar wind, with associated estimations of their damping rates and growth mechanisms.

Nonlinear processes in non-Maxwellian plasmas
Supervisors: Prof Iver Cairns and Dr Bo Li
Contact: Iver Cairns, 383, 9351 3961, i.cairns or boli @physics.usyd.edu.au

Most solar and interplanetary radio emissions are interpreted in terms of electron beams that produce electrostatic Langmuir waves and electromagnetic radiation near the electron plasma frequency and twice that frequency. The radiation is produced by nonlinear coupling of the Langmuir waves. Existing theory assumes that the plasma electrons and ions have Maxwellian distribution functions. However, observations show that the electron distributions are strongly non-Maxwellian and several arguments suggest that non-Maxwellian effects will significantly modify the rates at which the nonlinear processes proceed. This theoretical project involves calculating the nonlinear rates for non-Maxwellian electron distributions and then incorporating the results into our world-leading simulations of type II and III solar radio bursts.

Planetary Continuum Radiation
Supervisors: Profs Iver Cairns and Peter Robinson
Contact: Iver Cairns, 383, 9351 3961, i.cairns or p.robinson @physics.usyd.edu.au

All planets with magnetospheres in our solar system produce strong amounts of “continuum” radiation. No well accepted theory for this radiation exists. Two ideas have been proposed, both involving strong upper hybrid waves found near the magnetic equator in planetary magnetospheres. The first involves nonlinear wave-wave processes and the second linear mode conversion at density irregularities. This project involves development of the first semi-quantitative theory for continuum radiation. It involves re-assessing the efficiencies of known nonlinear processes (analytic theory) and linear mode conversion (computer simulations), and then combinining stochastic growth theory for the upper hybrid waves with the radiation efficiencies (analytic theory). Comparisons with spacecraft data will be pursued.

Wave growth below the electron plasma frequency
Supervisors: Prof. Iver Cairns and Dr Vasili Lobzin
Contact: Iver Cairns, 383, 9351 3961, i.cairns or v.lobzin @physics.usyd.edu.au
Electron beams drive Langmuir waves just above the electron plasma
frequency. Observations also often show waves well above and below the plasma frequency that cannot be in the Langmuir mode. A recent theory suggests that this wave growth can be due to electrons with a loss cone distribution rather than a beam distribution. Observations and recent simulations show loss cone and other localized features on the electron distribution that might drive waves. This project involves analytic and numerical calculations of the wave dispersion equation for electron distributions with loss cone, beam, and ring-beam distributions in order to understand wave growth below the plasma frequency, and to test the previous theory. The numerical calculations will use an existing code for solving the dispersion equation. Comparisons with spacecraft data may also be performed.

When are shocks unsteady and subject to reformation?
Supervisors: Prof. Iver Cairns, Dr Vasili Lobzin, and Dr Xingqiu Yuan (NRC Canada)
Contact: Iver Cairns, 383, 9351 3961, i.cairns or v.lobzin @physics.usyd.edu.au

Computer simulations sometimes show that one- and two-dimensional shock waves are unsteady, disappearing and reforming on a time scale close to the ion cyclotron period. Recent space observations provide support for reformation. However, the characteristic temporal and spatial scales of reformation are not known as functions of the shock’s Mach numbers and the magnetic field orientation. Nor are the magnitudes of the overshoots in the magnetic field and electric potential at the shock. Furthermore, while growth of waves via instabilities may cause shocks to become unstable, the relevant waves and instabilities are not known, This project will use existing simulation codes to study the properties of reforming shocks as functions of the shock Mach numbers and magnetic field orientation. Plasma waves related to the reformation will be identified and characterized. The results will be compared with published analytic theories, extended as required. An existing code that solves the wave dispersion equation may also be used to investigate the instabilities driving waves. This project will suit those wanting experience with computer simulations and theory.

Electron beams: efficient energy sources for solar radio emissions?
Supervisor: Dr Bo Li, Prof. Iver Cairns, Prof. Peter Robinson,
Contact: Dr Bo Li, 381, 9036 5109, boli@physics.usyd.edu.au

Solar radio emissions are usually driven by energetic electron beams associated with solar activity, like solar flares and coronal mass ejections. Generally, these electrons have speeds about one-tenth of light speed. The aim of this project is to study energy transfer from an electron beam to electromagnetic radiation in solar radio emissions. The project involves using existing state-of-the-art simulations to unravel the efficiency of electron beams as an energy source, i.e., to study conversion efficiency of electron beam energy into electromagnetic radiation energy. The energy input from the Sun into electrons and the radio energy output will be calculated. In addition, a new radiation process (linear mode conversion at density irregularities) will be parametrized from existing calculations and then incorporated into the simulations. The results from the simulations will be compared with data from spacecraft and ground-based instruments and with theoretical predictions. Effects of plasma wave off scattering off thermal ions on solar radio emissions Supervisor: Dr Bo Li, Prof. Iver Cairns, Prof. Peter Robinson,
Contact: Dr Bo Li, 381, 9036 5109, boli@physics.usyd.edu.au

Solar radio emissions observed at Earth and in space are usually due to nonlinear processes involving plasma waves, electromagnetic waves, and energetic electrons. This project will add the nonlinear process of plasma wave scattering off thermal ions to our existing simulations, which include other nonlinear radio-emission processes. The project involves deriving analytic expressions for the nonlinear emission rates using known techniques and then including them in our simulations. The simulation results with the new process will then be compared with previous work and observational data. This will allow us to assess the roles of scattering off thermal ions in solar radio emissions.

Accretion disks and plasma instabilities
Supervisor: Prof Iver Cairns
Contact: Iver Cairns, 383, 9351 3961, i.cairns@physics.usyd.edu.au

Accretion disks involve plasma and dust spiralling into a compact object like a black hole, neutron star, or white dwarf. The heating of accretion disks is not well understood. This project focuses on whether plasma waves and associated wave-particle heating should be important in accretion disks. The starting point is that charged particles in a magnetized medium with gradients in magnetic and electric fields and/or gravitational force develop a drift motion with velocity vector perpendicular to both the magnetic field and the gravitational force. These drifts lead to the plasma electrons, ions and charged dust particles moving relative to one another, potentially making the plasma unstable to the generation of waves and leading to associated wave-particle heating. The project will involve theoretical calculations of particle drift velocities and particle distribution functions, analysis of the resulting plasma instabilities and heating, and assessment of whether these effects can resolve several major problems in understanding astrophysical accretion disks.

Radio background of the interstellar medium: Radiation from astrospheres and supernovas Supervisors: Profs Iver Cairns and Peter Robinson
Contact: Iver Cairns, 383, 9351 3961, i.cairns or p.robinson @physics.usyd.edu.au

Shock waves propagating from the Sun to the outskirts of the solar system generate intense radio emissions observed by the Voyager spacecraft. A theory developed at U. Sydney predicts the levels and frequency of the emission quite well, with above 90radiation expected to move out into the local interstellar medium. Similar emission is expected from other stars (astrospheres) and from supernova shocks. This project involves applying the existing theory to supernova shocks and to other astrospheres, in order to assess whether they should produce observable emission and dominate the low frequency radiation (3-100 kHz) expected in the local interstellar medium.
Honours projects – Condensed Matter Theory 44

Research Projects in Condensed Matter Theory

Exploring the magnetic properties of undoped and doped oxide-based semiconductors for potential spintronics applications
Supervisors: Carl Cui and Catherine Stampfl

Dilute magnetic semiconductors are attracting enormous interest in relation to a new generation of semiconductorbased spintronics devices in which the electron spin, as well as charge, can be controlled and utilized. Before the spintronics revolution can begin, however, a much better understanding of spin interactions in solid state materials, as well as the roles of dimensionality, defects, and dopants is crucial. Presently, the associated physics is not well understood and is still the object of intense experimental and theoretical activity. The overall aims of the project include: 1. Extensive theoretical investigations, identification and fundamental understanding of potential undoped and doped binary transition metal oxide semiconductor materials. In particular, for undoped oxides, to shed light on the mechanisms responsible for the observed, and hitherto not understood, native magnetism in otherwise non-magnetic semiconductor materials. 2. Investigation of the interaction and behaviour of dopants and native defects, which have been proposed to hold the key for understanding the magnetism and the remarkably high Curie temperatures. These investigations will be carried out using state-of-the-art first-principles density-functional theory calculations.

Microscopic understanding the Cu/ZnO-based catalyst for hydrogen production from methanol from first-principles
Supervisors: Oliver Warschkow, Katawut Chuasiripattana, and Catherine Stampfl

The Cu/ZnO(0001) surface is widely used as a catalyst for the production of hydrogen from methanol and is thus of considerable relevance to the emergent hydrogen economy. A key to the further development of this catalyst system is a detailed atomic-scale understanding of the relation between surface structure and function versus environmental conditions such as copper content and state of surface oxidation. Density functional theory will be used to study the surface structures under varying experimental conditions and in particular the adsorption of relevant molecular fragments and the associated chemical reactions thereon.

Research Projects in High Energy Physics

Quarkonium states in first data from ATLAS
Supervisor: Dr Bruce Yabsley
Contact: Dr Bruce Yabsley, 366, B.Yabsley@physics.usyd.edu.au, 9351 5970

The quarkonia — bound states of a heavy quark and its antiquark — are among the most important particles in experimental work, and have played a key role in the development of the Standard Model. In particular, the lowest lying vector states, the J/ψ and the Υ(1S), have a very clean experimental signature (→ µ+µ−), are ideal for detector calibration, and serve as important signals for other physics processes. They will be copiously produced in pp collisions at the Large Hadron Collider, and will accessible in the first data taken by the ATLAS experiment. In this project we will use data from early ATLAS running to find J/ψ → µ+µ− and Υ(1S) → µ+µ− decays, and use them as a tool for a range of physics studies.

Characterizing the τ trigger with first data from ATLAS
Supervisor: Dr Aldo F. Saavedra
Contact: Dr Aldo F. Saavedra, 366, A.Saavedra@physics.usyd.edu.au, 9351 5970

An important aspect of the ATLAS experiment in its quest to discover new physics is the performance of its trigger system. It allows the detector to categorize and record events from the proton-proton collisions which are deemed useful and interesting. In this project the focus will be on the hadronically decaying τ lepton trigger. τ leptons are good probes for physics beyond the Standard Model (SM) as well as for the SM Higgs if it exists, hence it is important that its performance is well understood.

This study, which will include looking at first data from ATLAS, will measure the rate of the trigger, its efficiency and rejection power as a function of time, and will determine any biases introduced by the ATLAS detector components used for the trigger such as the calorimeter. If time permits new trigger algorithms will be explored. The study will be done using the Tau Trigger Performance package which has been developed by the Tau Trigger group for this purpose.

Measuring W → τ + ν with first data from ATLAS
Supervisor: Dr Aldo F. Saavedra
Contact: Dr Aldo F. Saavedra, 366, A.Saavedra@physics.usyd.edu.au, 9351 5970

The Large Hadron Collider (LHC) will start operations in September 2008. Its first double beam run will feature collisions at a lower luminosity (10^31cm−2s−1) and with a lower centre of mass energy (10 TeV) with respect to its design parameters. This should provide a good environment in which particles and processes that have previously been measured and understood can be used to calibrate and disentangle the response of the different components of the ATLAS detector. One of these particles is the charged vector boson W and a good number of them should be collected during these first runs.

At Sydney the focus of our ATLAS efforts have been on the reconstruction of the hadronically decaying τ leptons since they are good probes for physics beyond the Standard Model. Thus this project will focus on one of the decay modes of the W , the W → τ + ν decay mode. Using this decay mode the aim of the project will be to measure the performance of the τ reconstruction and determine any biases that the τ identification will introduce when looking at the measured properties of the W .

Neutrino detection in Belle
Supervisor: Dr Kevin Varvell
Contact: Dr Kevin Varvell, 355, K.Varvell@physics.usyd.edu.au, 9351 2539

Belle is an excellent detector for identifying most of the charged and neutral particles that are produced in the electron-positron collisions that we study. Neutrinos, however, are a different proposition; they interact so weakly with matter that they leave the detector (and usually the galaxy) unseen. Many important decays that are studied with Belle produce neutrinos, so this is a problem. What can be done, however, is to use all of the particles that are detected, and knowledge of the incoming beam energies, to try to reconstruct the neutrino. This project will study the problem of neutrino reconstruction in Belle in a systematic way and try to devise ways to improve it, building on a considerable amount of work already done within the group on this topic. The project will involve the study of real and simulated data with existing computer analysis tools. Semileptonic B meson decays to mesons containing light quarks in Belle
Supervisor: Dr Kevin Varvell
Contact: Dr Kevin Varvell, 355, K.Varvell@physics.usyd.edu.au, 9351 2539

Using the Belle experiment’s large data set and a technique known as “full reconstruction”, we have been successful in measuring the rate at which B mesons decay to final states containing a lepton (electron or muon), a neutrino, and a single particle containing an up quark (specifically π, ρ or ω mesons). These decays, which are rare (of order one in ten thousand B decays are of this type) are important inasmuch as their rate determines a parameter of the Standard Model, known as Vub, related to CP violation.

This project will build on this work using the latest available data from Belle, in particular to search for two other related decay modes, where the meson produced is an η or η . The rates determined by previous studies have rather large uncertainties and we may well be able to do better. The project will involve the study of real and simulated data with existing computer analysis tools.

Radiative transitions of D mesons in Belle data
Supervisor: Dr Bruce Yabsley
Contact: Dr Bruce Yabsley, 366, B.Yabsley@physics.usyd.edu.au, 9351 5970

Radiative transitions between related mesons ( cf. transitions between different energy levels in atomic physics) are important for understanding meson structure, and the binding potential between quark and antiquark. Meson spectroscopy has been shaken up in recent years by the discovery of unexpected states in data from the B-factories (Belle and BaBar), and measurement of theoretically clean transitions is an important constraint on models. This project will use a mix of “toy” and full Monte Carlo, data processing in ROOT, and some Belle data to develop and test a method for analysis of 1P → 1S radiative transitions of D mesons. These transitions can only be studied at the B-factories, and have not yet been measured. This project has the potential to open onto post-honours work, for example PhD research on Belle.

Research Projects in Medical Physics

Radionuclide Therapy Dosimetry: Measuring 3D Dose Distributions in Gels
Supervisor: Zdenka Kuncic, Clive Baldock, Dale Bailey
Contact: Zdenka Kuncic, z.kuncic@physics.usyd.edu.au, 9351-3162, rm. 415

Internal radiation therapy uses radionuclides to irradiate localised, target tissue. Unlike external beam radiotherapy, where it is relatively straightforward to calculate the absorbed dose of radiation with low uncertainties, in radionuclide therapy the uncertainties can be considerable. Indeed, a major challenge in nuclear medicine is to establish robust dosimetry methods that can accurately relate source activity to delivered dose for individual patients. A novel technique using tissue-equivalent gel compounds that polymerise when irradiated offers arguably the most viable method for radionuclide dosimetry. This method is yet to be fully evaluated with numerical modelling of the radiation transport. The aim of this project is to develop a physical model for radionuclide therapy dosimetry using Monte Carlo numerical techniques to determine 3D radiation dose distributions and to calculate total absorbed dose as a function of radionuclide activity. The numerical results will be compared against experimental data.

Electron Beam Interactions with a Thick Target: Quantifying the Effects of Backscatter Academic supervisors: Zdenka Kuncic, Clive Baldock
Clinical supervisors: Robin Hill, Gwi Cho (Radiation Oncology, RPAH)
Contact: Zdenka Kuncic, z.kuncic@physics.usyd.edu.au, 9351-3162, rm. 415

Electron beams are used in radiation therapy to treat skin cancers, often using high density materials (e.g. lead) to shield healthy tissues. For example, one could use lead shielding underneath the ear while it is being irradiated with electrons. However, at the interface between tissue and lead, there are significant changes in the attenuation and scatter of electrons when they strike the lead. This project investigates the changes in radiation dose close to and at a distance from the interface between tissue and lead. The changes in dose and the dependence on atomic number of the shielding material and distance from the interface will be investigated and quantified. A Monte Carlo program will be used to simulate the radiation beam and its interactions and the numerical results will be compared with experimental measurements using radiochromic film.

The Physics of Cone Beam CT Images in Radiation Therapy
Academic supervisors: Zdenka Kuncic, Clive Baldock
Clinical supervisors: Robin Hill, Gwi Cho (Radiation Oncology, RPAH)
Contact: Zdenka Kuncic, z.kuncic@physics.usyd.edu.au, 9351-3162, rm. 415

A recent development in radiotherapy is the use of low energy x-ray beams to image the patient to ensure the correct anatomical position. The advantage of using low energy x-rays is improved image quality and clearer definition of the patients anatomy. The on-board imager (OBI) unit is usually mounted orthogonally onto the medical linear accelerator that is used to deliver the radiation treatment. One feature of the OBI is the ability to generate a cone beam CT of the patient from the x-rays, giving a 3D data set. To date, there have been limited studies on evaluating the properties of the x-ray beams and the radiation doses from the cone beam CT images. In this project, we will use a Monte Carlo model to investigate the properties of these low energy x-ray beams and to calculate the radiation dose to the patient.

Measuring, and Correcting for, Inter-Modality Motion in PET/CT
Supervisor: Roger Fulton
Contact: Roger Fulton, r.fulton@physics.usyd.edu.au, 9351 0954

In PET/CT studies of the brain, motion of the head frequently occurs between the CT scan, which is performed first, and the PET scan. The resulting mis-registration of the CT and PET image sets causes errors in the corrections applied for scatter and attenuation, which are expressed as artifacts in the reconstructed PET images. These artifacts may result in erroneous image interpreation, incorrect diagnosis and inappropriate decisions regarding subsequent patient management. The misregistration may also in false conclusions about the precise anatomical location of lesions seen on the PET scan, with implications for patient prognosis and management. The aim of this project is to develop a practical method for detecting and quantifying (in six degrees of freedom) rigid motion of the head in the interval of 1 min between the CT and PET scans, using one or more optical motion tracking systems. Observed head motion will be compensated by applying a spatial transformation, converted to the scanner coordinate system, to the reconstructed CT volume to bring it into correct registration with the PET data prior to reconstruction of the PET images. The project will be conducted in the Department of Nuclear Medicine, PET and Ultrasound at Westmead Hospital.
Implementing GATE Simulation Tools on the University’s New High Performance Computing Facility (SILICA)
Supervisor: Roger Fulton
Contact: Roger Fulton, r.fulton@physics.usyd.edu.au, 9351 0954

Geometry and tracking (GEANT4) is a Monte Carlo package designed for high energy physics experiments. It is also an important tool for simulations of nuclear medicine SPECT and PET acquisition systems, which nowadays are usually performed using a dedicated package known as GEANT4 Application for Tomographic Emission, or GATE. GATE allows the user to realistically model experiments using accurate physics models and time synchronization for detector movement. The downside is the long computation time required to generate simulations with realistic numbers of events (typically many days on a fast desktop computer). The aim of this student project is to adapt the GATE source code to the multi-node architecture of the University of Sydney’s new High Performance Computer for the Faculties of Science and Engineering, also known as the Silica Cluster (http://www.hpcf.chem.usyd.edu.au/index.html). Silica is a 600-core rack mounted cluster with 74 compute nodes, each having two Intel Xeon quad-core processors, and 16GB of memory, as well as a head node which handles interactive use and storage. This will enable much faster simulations and provide a valuable resource for future researchers. The project is best suited to a student with a special interest, and some experience, in software development. Ref: Cluster computing software for GATE simulations, Beenhouwer J. et al., Med. Phys. 2007 Jun;34(6):1926-33

Software for NEMA 2007-compliant PET acceptance testing
Supervisor: Roger Fulton
Contact: Roger Fulton, r.fulton@physics.usyd.edu.au, 9351 0954

The aim of this project is to develop software for the analysis of positron emission tomography (PET) acceptance test data. Acceptance tests are normally performed on-site whenever a new PET scanner is installed to check that its performance is within specifications in terms of spatial resolution, sensitivity, and noise equivalent count rate. The NEMA 2007 standard clearly specifies phantoms, and procedures for the acquisition and analysis of acceptance test data. PET equipment manufacturers specify their equipment in terms of NEMA performance parameters, and most provide software that customers can use to calculate these parameters during acceptance testing. However no manufacturers release the source codes of their software, which makes it impossible to independently verify their conformance to the NEMA standard. Further, since each manufacturer implements the software differently, it is hard for intending purchasers to confidently inter-compare advertised performance specifications. The project involves the development and validation of one or more open source NEMA-compliant analysis programs (e.g. to calculate spatial resolution, sensitivity or noise-equivalent count rate) for release to the international PET user community. Because of their open source nature and verifiability it is likely that they will be adopted by the user community for comparison with proprietary software, and developed further. In the course of the project the student will need to become familiar with the physics of PET imaging, the manipulation and format of PET data, and the NEMA standard. They will also develop programming skills in a language such as IDL, Java or C. The programming involved is of low to moderate difficulty. However an aptitude for or prior exposure to computer programming will be an advantage.

Space Radiation Dosimetry: Quantifying Health Risks of Human Exploration in Deep Space Supervisor: Zdenka Kuncic
Contact: Zdenka Kuncic, z.kuncic@physics.usyd.edu.au, 9351-3162, rm. 415

Galactic cosmic rays (CGRs) and solar energetic particle events (SEPs) pose a serious threat to humans in deep space. Exposure to ionising space radiation, particularly protons, alpha particles and heavier ions, can result in serious radiobiological effects that can lead to irreparable damage to critical organs and the central nervous system, as well as cancer and mortality. Unfortunately, the actual health risks are difficult to quantify because very few studies have been conducted on measuring doses of radiation relevant to deep space missions. This issue is receiving renewed attention from NASA, which is planning long-duration manned missions to the Moon and to Mars. The aim of this project is to develop a physical model for space radiation dosimetry that will accurately calculate radiation dose to human tissue resulting from long exposure to ionising flux from GCRs and SEPs. A Monte Carlo radiation transport code will be used to calculate the absorbed dose for a range of different physical conditions (including in particular fluctuations in energetic particle fluxes) and to investigate the effectiveness of different spacecraft shielding materials.
Radiation Dose Calculations for Intensity Modulated Beams in a Cylindrical Phantom Supervisors: Peter Greer, Zdenka Kuncic, Clive Baldock
Contact: Zdenka Kuncic, z.kuncic@physics.usyd.edu.au, 9351-3162, rm. 415

This project will calculate benchmark dose distributions for intensity modulated radiation beams in a cylindrical phantom. These benchmark results will be used to validate dose reconstruction algorithms based on measurements made by imaging systems. Monte Carlo methods will be used to benchmark the linear accelerator (linac) beam using an existing model that has been previously verified for similar linacs at beam energies of 6 MV and 18 MV. The results will be validated by comparing against measurements in flat water phantoms. A multi-leaf collimator component will then be implemented into the linac model to calculate the dose for intensity modulated radiotherapy (IMRT) beams. The dose calculations will then be compared against measured film planar doses provided by Newcastle Mater Hospital. The model will then be developed further for a cylindrical phantom geometry. Dose distributions will be calculated for combined open and IMRT beams from different linac gantry angles. These results will then be compared to those obtained from imaging systems in order to evaluate the accuracy of dose reconstruction algorithms.

Investigation of Direct-Detection Electronic Portal Imaging Device
Supervisors: Peter Greer, Zdenka Kuncic, Clive Baldock
Contact: Zdenka Kuncic, z.kuncic@physics.usyd.edu.au, 9351-3162, rm. 415

This project will investigate by means of Monte Carlo radiation transport simulations the dose deposition in a novel direct detection imaging system dosimeter that is currently under development. The project will involve benchmarking the Monte Carlo phase space and Electronic Portal Imaging Device (EPID) model and investigating the effect of varying the different physical components in the model, including in particular the buildup material in the detector. An important goal is to determine why the response with copper buildup differs from that with solid water buildup and to identify the differences in the particle interactions. This will also be repeated for backscatter material. The project will determine why the response with depth of buildup and buildup material is different from that of an ion-chamber. It will also examine whether copper buildup in the indirect EPID configuration (with phosphor) changes the response from that for solid water buildup.

Quantifying Scattering Artefacts in Cone-Beam Optical Computed Tomography Supervisors: Stephen Bosi, Clive Baldock, Zdenka Kuncic
Contact: Zdenka Kuncic, z.kuncic@physics.usyd.edu.au, 9351-3162, rm. 415

Gel dosimeters change their transparency under exposure to ionising radiation and can be thought of as a 3-D photographic medium for measuring a 3-D map of radiation to verify the dose to be delivered to radiotherapy/radiosurgery patients. The 3-D image can be read from a gel dosimeter using an Optical Computed Tomography (OCT) scanner – either a laser OCT or the more recent cone-beam OCT. Cone-beam OCT is faster, simpler, more robust and reliable than laser scanning, but it suffers more severely from artefacts caused by stray, scattered light which can distort the measurement of radiation dose. Scattering artefacts might be able to be corrected by either including a mathematical model of light scattering in the reconstruction software, or by including polarising filters in the scanner to filter out scattered light. This project will involve using Monte Carlo techniques to test the effectiveness of these two strategies in improving the accuracy of cone-beam OCT.

Investigation of Anatomical Priors as Regularisation in Multi-Pinhole SPECT Reconstruction Supervisor: Steve Meikle, Brain and Mind Research Institute
Contact: Steve Meikle, s.meikle@usyd.edu.au

Pinhole collimation is used in single photon emission computed tomography (SPECT) to image small objects, such as the rodent brain, at high spatial resolution. To boost the detection efficiency of this imaging system, we are exploring the use of multiple pinhole apertures that increase the gamma photon flux incident on the detector. However, this approach also results in overlapping (multiplexed) projections, leading to slower convergence of the iterative reconstruction and image artifacts. In this project, we will address this problem by investigating the use of anatomical image data (in the form of a digital brain atlas) as prior information to regularise the reconstruction, thus guiding it towards a more accurate result. The project involves computer simulation and software development (using IDL) to implement an anatomical MAP algorithm that we have previously applied to human PET/CT data. The student will gain experience in medical image reconstruction, software development and image quality evaluation.
FDG Imaging Hot Spots
Supervisors: Phil Vial, Lois Holloway (Liverpool & Macarthur Cancer Therapy Centres) Contact: philip.vial@sswahs.nsw.gov.au, lois.holloway@sswahs.nsw.gov.au, or
Zdenka Kuncic (z.kuncic@physics.usyd.edu.au, rm. 415)

The aim of this study is to establish if the hot spots, representative of highly active tumour in FDG-PET images, are consistent over the course of treatment. If this is the case then it may be possible to deliver boost doses to these volumes. This is the first step in an investigation to predicting patient relapse allowing for individual patient targeted radiotherapy. Liverpool Hospital has one of the few PET/CTs in Sydney. This is a unique opportunity to learn about CT and PET imaging and how they are applied to cancer therapy. The student will use pre-existing radiotherapy patient images (PET and CT) acquired before and after treatment. They will investigate methods to analyse changes in tumour volumes and activity. The student will learn skills in handling and manipulating medical image data. Some software development may be necessary (e.g. MatLab).

Dose Assessment for Cone Beam Imaging
Supervisors: Phil Vial, Lois Holloway (Liverpool & Macarthur Cancer Therapy Centres) Contact: philip.vial@sswahs.nsw.gov.au, lois.holloway@sswahs.nsw.gov.au, or
Zdenka Kuncic (z.kuncic@physics.usyd.edu.au, rm. 415)

Most modern linear accelerators (linacs) are fitted with electronic devices (EPIDs) to perform patient imaging on the treatment table before treatment. Kilovoltage cone-beam computed tomography (kV CBCT) is one such device and incorporates an x-ray tube and a flat panel detector mounted on the same gantry with the linear accelerator. The purpose of this study is measure dose to the skin and other critical structures from KV CBCT on an Elekta Linac and compare these doses with the Megavoltage (MV) CBCT facility on Siemens Linac and a conventional kV CT scanner. A new Elekta linear accelerator has been installed at Liverpool Cancer Therapy Centre with a kilovoltage CBCT. This project will give the student an opportunity to learn about the new imaging technology and its impact on doses received by patients undergoing image guided radiation therapy (IGRT). The student will also learn about thermoluminescent dosimety (TLD). This project involves a large component of experimental work.

Dosimetric Characteristics of EPIDS
Supervisors: Phil Vial, Lois Holloway (Liverpool & Macarthur Cancer Therapy Centres) Contact: philip.vial@sswahs.nsw.gov.au, lois.holloway@sswahs.nsw.gov.au, or
Zdenka Kuncic (z.kuncic@physics.usyd.edu.au, rm. 415)

The high spatial resolution electronic portal imaging detectors (EPIDs) is well suited to dosimetry of intensitymodulated radiotherapy (IMRT) beams. The student will perform a thorough dosimetric characterisation of the EPID. This project includes a mix of experimental work and data analysis using MatLab. The student would be trained in the operation of a medical linear accelerator, EPIDs, EPID dosimetry, and MatLab. EPID dosimetry with Siemens equipment has not been as widely characterised/published as other vendor systems. This project is an opportunity to lead the way in EPID dosimetry with Siemens equipment. Experienced supervision is available from researchers who have previously published work in this area. The student will implement an EPID calibration system based on previously published methods. Successful completion of this work could provide the opportunity of an exciting post-graduate project.

Research Projects in Photonics and Optical Science

CUDOS

Development of optofluidic photonic integrated circuits
Supervisors: Snjezana Tomljenovic-Hanic, Christian Karnutsch and Martijn de Sterke
Contact: snjezana@physics.usyd.edu.au or desterke@physics.usyd.edu.au

Optofluidics, the integration of optical and fluidic devices, takes advantage of the unique properties of liquids to create optical systems which can be reconfigured and adapted to requirements. With this powerful combination our group at CUDOS has demonstrated a novel way of controlling light in photonic crystals (PCs). These consist of a slab with very small holes; by filling some of the holes with a liquid the light propagation can be controlled. Recent advances in micromanipulation of PCs are now allowing precise control of this fluid infiltration. In this project you will go a step further and investigate schemes for PC-based optofluidic circuits consisting of multiple components including waveguides and cavities. Using existing, user friendly, software you will create novel optical and fluidic devices. This project will also involve collaboration with experimentalists at CUDOS that will turn your designs into real devices.

Reconfigurable nanofluidic integrated optical circuits
Supervisors: Christian Karnutsch, Snjezana Tomljenovic-Hanic, Ben Eggleton
Contact: Christian Karnutsch, c.karnutsch@physics.usyd.edu.au
http://www.physics.usyd.edu.au/cudos/research/opto-fluidics.htm

In this highly innovative project, students will combine the technology of nanofluidics together with photonic crystals, creating a platform for an advanced optofluidic technology based on integrated reconfigurable optical circuits. This new technology will lay the foundation for future innovative devices with an unprecedented level of functionality. The students will simulate, design, fabricate and experimentally investigate a suite of nanofluidic optical components, realised in silicon photonic crystal structures. A fluid infiltration process will be employed that enables the selective filling of single, nanometre-scale pores of the photonic crystal. In this way, a variety of optical functional geometries such as light-confining nanocavities and waveguides can be realised, enabling complex photonic circuits.

Optofluidic circuits using ionic liquids
Supervisors: Christian Karnutsch, Ross McPhedran, Ben Eggleton
Contact: Christian Karnutsch, c.karnutsch@physics.usyd.edu.au
http://www.physics.usyd.edu.au/cudos/research/opto-fluidics.htm

Optofluidics is a burgeoning field of research that integrates microfluidics with nanophotonics. Demonstrations of optofluidic devices exploit the characteristics of micro-scale volumes of fluid to achieve dynamic manipulation of optical properties. One of the many possibilities offered by optofluidics is a method to write, tune or reconfigure photonic devices, overcoming several key challenges to the otherwise static nature of such emerging technologies. In this project the student will employ photonic crystals, which benefit significantly within optofluidic architectures due to their potentially high light-liquid interaction capability. The student will develop novel photonic crystal components using ionic liquids, which provide an environmentally sound platform due to their non-volatile nature. Ionic liquids are salts whose melting point is relatively low, even as low as room temperature. These liquids can then be infiltrated within photonic crystals to achieve innovative geometrically complex optofluidic components.

Plasmonic sensors
Supervisors: Christian Karnutsch, Judith Dawes, Ross McPhedran
Contact: Christian Karnutsch, c.karnutsch@physics.usyd.edu.au
http://www.physics.usyd.edu.au/cudos/research/plasmon.html

Metals are typically strong absorbers of light. However, by miniaturization of photonic circuits, metallic structures can provide exceptional methods of manipulating light at length scales smaller than the wavelength. An interface between a dielectric and a metal can support a surface plasmon, which is a coherent electron oscillation that propagates along the interface together with an electromagnetic wave. The short-wavelength plasmons enable the fabrication of nanoscale optical integrated circuits, in which light can be guided, split, filtered, and even amplified using plasmonic integrated circuits that are smaller than the optical wavelength. These have many possible applications, including (bio-)sensing, increasing the efficiency of LEDs, nanolithography, optical storage, solid-state lighting, and optical interconnects. In this project, the student will design, fabricate and experimentally investigate plasmonic structures, with a particular focus on realising a plasmonic sensor based on crossed metallic gratings that totally absorb incident light.

Photonic crystal waveguides
Supervisors: Snjezana Tomljenovic-Hanic and Martijn de Sterke
Contact: m.desterke@physics.usyd.edu.au

Photonic crystals are structures in which the refractive index varies periodically with position, typically by drilling sub-micron holes in a uniform slab of high-index material. Via the Bragg reflection that occurs in periodic media, photonic crystals allow for exquisite control of the propagation of light. Defects in an otherwise periodic hole array can lead to a variety of devices–a line defect, for example, forms a waveguide since any light trying to get out is Bragg reflected back in. A novel way to generate such a waveguide is by slightly changing the refractive index of the slab in a line-shaped area, which can be done in a number of ways. It was recently claimed that the orientation of the waveguide with respect to the periodic lattice determines the type of waveguide that is obtained–the waveguide properties, such as the group velocity and the dispersion, can thus be tuned simply by varying the direction. We will investigate this claim theoretically and numerically, and study the types of waveguides that can be obtained in this way.

High-Q cavities in photonic crystals
Supervisors: Snjezana Tomljenovic-Hanic, Martijn de Sterke, and Mike Steel (Macquarie Univ.) Contact: m.desterke@physics.usyd.edu.au

Optical micro-cavities in photonic crystal slabs have many applications, for example as all-optical switches and sensors. Any cavity must be able to confine the light in all-directions and be able to store it for many optical cycles. We characterise a cavity by its Quality Factor Q, essentially the number of cycles for which light can be stored before it is absorbed or leaks out. Now most photonic crystals consist of a thin, high-refractive index slab, with periodically placed holes. While these holes confine the light in the plane of the slab by Bragg reflection, confinement in directions outside this plane rely on total internal reflection, which for cavity modes is imperfect. Careful design is required to attain high Qs. We know that we can attain high Q by making cavities with a smooth profile, and we have a unique experimental capability to make them, however, the optimum form of the required profile is unknown. In this project, we will use analytic methods and supercomputer simulations to design an optimum cavity profile. This project will directly inform future experimental work within CUDOS.

Beating the Rayleigh limit
Supervisors: Martijn de Sterke, Mike Steel (Macquarie Univ.), and Adel Rahmani (UTS) Contact: m.desterke@physics.usyd.edu.au

As physics concentrates increasingly on nano-scale problems, there is growing pressure from biology, medicine and engineering to find new ways to probe very small structures. Electron microscopes provide one approach, but there is much information that is only available through observation with visible or infra-red light. However, the diffraction limit tells us that with conventional microscopes we can’t resolve images smaller than about λ/2, so techniques for “beating the diffraction limit” are of great interest. It has long been known that this missing information is lost through evanescent waves which decay very quickly and don’t reach our detectors. In 2007, it was discovered that merely by placing a collection of random scatterers near the object, the evanescent waves can be turned into propagating waves that can reach our detectors and so produce a sub-diffraction limit image. This is an exciting development but it has only been observed in the microwave. In this project, we study the potential to extend this technique to the optical regime, where it could have real impact. The approach will combine a study of Green functions and the Local Density of States, with large scale numerical simulations.

Optical fiber nanowires characterization for efficient nonlinear processing
Supervisors: Ben Eggleton, Eric Magi, Martijn de Sterke
Contact: b.eggleton@physics.usyd.edu.au

Optical fiber nanowires can be made by tapering conventional optical fibers down to sub-micron cross sections. Because they can confine light very tightly, these nanowires offer very strong optical nonlinearities that can be exploited in a range of ultrafast optical signal processing applications. Of particular interest are processes which depend very sensitively on the wave number of the light propagating through the nanowire, which in turn depends on the nanowire’s diameter. Until recently it has been impossible to measure the diameter precisely, but it was recently shown it that can be achieved. In essence it comes down to measuring a resonant frequency as a function of the length along the taper. This project will develop a technique for probing the nanowire dimensions and mapping how the diameter fluctuates with position. Based on this information we will examine theoretically how these fluctuations affect phase matched nonlinear processes. This project will involve sophisticated experimental technique and some theory as well.

Cloaking by Plasmonic Resonance of Spherical Particles
Supervisors: Ross McPhedran (ross@physics.usyd.edu.au), Martijn de Sterke (m.dsterke@Physics.usyd.edu.au), Dr. Chris Poulton, University of Technology, Sydney.
Contact: Ross McPhedran ross@physics.usyd.edu.au, Martijn de Sterke m.dsterke@Physics.usyd.edu.au

One of the hottest topics currently in optics is the cloaking of objects, i.e., to make them look invisible. There are (at least) two ways to do this. One way is to make a hollow particle with a shell which guides electromagnetic waves smoothly round the particle and then reunites them as if the particle and anything inside the cavity were not there. A second way, which we have pioneered, is to use a coating with a surface plasmon, a wave that can exist on the interface between a dielectric and a metal. This resonance can cancel out probing electromagnetic waves in a region around the coated particle, creating a “shadow zone” in which particles are cloaked. Our work has been limited to cylindrical particles, and needs to be extended to the much more realistic case of spherical particles. The project will involve analytic and numerical work on point dipoles placed near spherical particles coated with materials carefully chosen to give plasmonic resonances and cloaking effects. We hope the project will set the stage for an experimental demonstration of cloaking by resonance.

Plasmonic sensors in Photonic crystal fibres
Supervisors: Boris Kuhlmey, Maryanne Large, Ross McPhedran
Contact: Boris Kuhlmey b.kuhlmey@physics.usyd.edu.au, Maryanne Large m.large@usyd.edu.au

Surface plasmon resonance sensors are amongst the most sensitive chemical and biological sensors. They are based on exciting a surface wave resulting from charge carriers coupled to a light wave, at the interface between a metal and a dielectric, such as glass. Existing surface plasmon resonance sensors are based on bulk optics, and are rather large and expensive. Photonic crystal fibres are optical fibres with microscopic holes running along their length. Coating these holes with metal could yield cheap, disposable and miniature surface plasmon resonance sensors. This project will consist in the numerical analysis and design of surface plasmon resonant photonic crystal fibre sensors, and look into their experimental fabrication. Another project on developing a novel analytical model for calculating the properties of surface plasmonic photonic crystal fibres is also available.

Photonic crystal fibres as metamaterials
Supervisors: Boris Kuhlmey, Maryanne Large, Ross McPhedran
Contact: Boris Kuhlmey b.kuhlmey@physics.usyd.edu.au, Maryanne Large m.large@usyd.edu.au

Metamaterials are novel artificially designed materials with unprecedented electromagnetic properties. It has been suggested and indeed demonstrated that such metamaterials can be used for electromagnetic cloaking (the ability to make things invisible) or have negative refractive indices, which can be used to make perfect lenses and even negate the Casimir force. Metamaterials are made of a more or less periodic set of electromagnetic resonators, which need to be smaller than the wavelength for which the metamaterial should have those amazing properties. Metamaterials have been demonstrated at very long wavelengths (radio waves) where the size of the resonators can be of the order of a centimetre, but also at optical wavelengths using appropriately arranged gold nanoparticles. In both cases the fabrication of metamaterials is extremely time consuming, and only very small quantities can be made. This project will look at making metamaterials literally by the kilometre, using metal-coated photonic crystal fibres. There are numerical, theoretical as well as experimental aspects to the project, the balance of which can be decided with the student.

Hybrid ARROW fibres
Supervisors: Boris Kuhlmey, Ben Eggleton
Contact: Boris Kuhlmey b.kuhlmey@physics.usyd.edu.au

Photonic crystal fibres are optical fibres with microscopic holes running along their length. Filling the holes of PCFs with fluids has enabled the creation of a number of novel photonic devices, although so far these have relied on all holes being filled by the same material. We have recently developed a technique to selectively infiltrate fluid into only some, rather than all, of the holes making up the PCF lattice. This opens up the prospects of new classes of fibre devices, such as all-in-fibre optical frequency triplers and broadband dispersion compensators. Reports of the theoretically expected behaviour of such compound wave-guiding structures are increasingly appearing in the research literature. An exciting opportunity exists to advance this topic in an experimental framework. The first part of the project will involve studying the characteristics of such novel selectively filled fibre devices numerically. A second aspect will be in construction of the best designs experimentally using our selective infiltration techniques. Finally a third part of the project will be in testing the novel structures in the laser laboratory. The experimental testing techniques we have available include linear transmission and mode imaging, broadband dispersion characterisation, via spectral interferometry with a supercontinuum laser source, and nonlinear pulse propagation studies using ultrafast pulsed laser systems.

Photosenstive writing of chalcogenide photonic crystal devices using a NSOM technique Supervisors: Dr. Christelle Monat, Dr. Christian Grillet, Dr. Snjezana Tomljenovic-Hanic and Prof. Ben Eggleton
Contact: monat@physics.usyd.edu.au

This project will investigate a novel technique based on NSOM (near-field scanning optical microscope) for creating precisely engineered microphotonic devices from a planar photonic crystal (PhC) structure. Planar PhC, which consist of a thin, high index dielectric membrane patterned with a 2D periodic array of air holes, are a promising platform for realizing planar integrated circuits. However, in order to achieve desirable functionalities both careful design and high accuracy fabrication are required. Utilizing the photosensitivity of chalcogenide glass (i.e. the refractive index change due to illumination by visible light) represents a flexible and elegant way to realize some of these devices. Because NSOM relies on a sub-wavelength diameter aperture (typically a fiber tip) brought very close to the sample’s surface, its use as the illumination source should provide a resolution far better than conventional optical microscopy. This project will investigate experimentally the possibility of exploiting this NSOM technique to create a range of various functionalities such as small mode volume high quality factor optical resonators with unprecedented control. NSOM writing and development will be performed in collaboration with EMU (Electron Microscopy Unit) and testing of the devices will be carried out in the CUDOS clean room nanophotonics laboratory using an evanescent wave probing technique.

Modelling of optical resonators for slow light and sensing applications
Supervisors: Dr Snjezana Tomljenovic-Hanic, Dr Christelle Monat and Prof. Martijn de Sterke Contact: Dr Snjezana Tomljenovic-Hanic, Rm 314, snjezana@physics.usyd.edu.au, 9351 3953

The ability of photonic crystals to trap and guide light arise from having defects in the periodic structure. Therefore the critical step in the fabrication is the incorporation of defects, such as waveguides and cavities, in a controllable way. At present, the design of such structures is finalized at the stage of fabrication. However there are ways to tune existing defects, or even induce defects by varying the refractive index within the PCS structure. In this project you will consider the photosensitivity of chalcogenide glasses, special types of glasses with a refractive index that changes permanently under light exposure. Using this approach, optical resonators for slow light and sensing applications can be induced. Of particular interest will be slow light structures, in which the light travels at only a fraction of the speed of light in the medium. This theoretical study will be closely related with ongoing experiments in CUDOS.

Dispersion engineering in silicon photonic crystal using liquid infiltration.
Supervisors: Dr Christian Grillet, Dr Christelle Monat, Dr Christian Karnutsch
Contact: grillet@physics.usyd.edu.au

Planar photonic crystals are periodic structures at the nanometer scale e.g. a periodic lattice of air holes in a thin silicon membrane which represent a promising platform for realizing compact and integrated optical devices (filter, laser, etc). An interesting feature of these structures is the possibility to fully control the properties of light at the wavelength scale. In particular, light propagating across these structures is significantly slowed down at some frequencies. These slow down regions are typically accompanied by high group velocity dispersion which tends to distort a pulse of light as it would propagate through the structure. By optimizing the geometry of the periodic lattice of air holes in silicon, it is however possible to slow the light down and minimize distortion effects. This generally requires nanometer-scale positioning of the holes, difficult to achieve using conventional fabrication techniques. An elegant and completely novel solution is to infiltrate selected air pores with an appropriate liquid, which is possible using the microtip based selective infiltration technique developed at CUDOS. The aim of this project will be to investigate these new possibilities for dispersion engineering in photonic crystals, perform the infiltration step within silicon photonic crystal waveguides, and measure the optical properties of the infiltrated structure to demonstrate that it is indeed possible to slow down optical pulses without distorting them. In addition to the creation of non dispersive slow light, this approach has natural and direct application in optofluidic sensing.

Nonlinear effects in slow light photonic crystals
Supervisors: Dr Christelle Monat, Dr Christian Grillet, Prof. Ben Eggleton
Contact: monat@physics.usyd.edu.au

Slowing the light down is of high interest for nonlinear applications, because the optical energy density increase that occurs in the slow light regime strongly enhances the interaction between light and the nonlinear material through which it propagates. It is therefore predicted that nonlinear phenomena, such as Raman scattering, frequency conversion, third harmonic generation, will be strongly enhanced in the slow light regime. Silicon photonic crystals represent a promising platform for effectively slowing the light down at the micrometer scale level, and study these nonlinear enhanced effects. The aim of this project will be first to model and design photonic crystals structures to produce appropriate slow light dispersion for the targeted nonlinear effect, then to experimentally probe these devices in the nonlinear regime. The experiments will involve butt-coupling using optical fibers, and possibly a Near Field Optical Microscope, which can produce a map of the emission arising from the photonic crystal by scanning a nanometer tip at the surface of the structure to capture selectively the light emission.

Fiber-based integrated devices for stellar interferometry
Supervisors: Dr. Eric Magi, D.r Christelle Monat, Dr. Christian Grillet, Dr. Guillermo Martin (LAOG / France, http://www-laog.obs.ujf-grenoble.fr)
Contact: Dr. Christian Grillet, 303B, grillet@physics.usyd.edu.au, 9036 9430

Using chalcogenide fibers, is it possible to combine the optical signal collected from different telescopes and achieve modal filtering in a single device. The quality of the interference fringes (contrast) depends on the ability of the fiber to filter-out high order modes, as well as to maintain the polarization state of the beam. In this project, we propose to realize and characterize different chalcogenide based samples, from a simple straight single mode fiber embedded in a lower index planar structure to more elaborate devices like Y-junctions, MachZehnder, in order to study rejection ratio (nulling), chromaticity (wavelength dependence of the nulling), and temperature dependence. Design will be performed in collaboration with LAOG (Astrophysics Laboratory of Grenoble Observatory) which is involved in the R and D programs dedicated to the preparation of the ESA DARWIN mission aiming at discovering life on Earth-like exoplanets. Testing of the devices will be carried out in the CUDOS clean room nanophotonics laboratory.

Photosensitive writing of novel integrated devices for stellar interferometry
Supervisors: Dr. Christelle Monat, Dr. Christian Grillet Dr. Guillermo Martin
Contact: Dr. Christian Grillet, 303B, grillet@physics.usyd.edu.au, 9036 9430

This work is a collaborative effort between CUDOS and LAOG (Astrophysics Laboratory of Grenoble Observatory) which is involved in the R and D programs dedicated to the preparation of the ESA DARWIN mission aiming at discovering life on Earth-like exoplanets. Chalcogenide glasses are known for their photosensitivity (i.e. possibility to modify locally the refractive index by exposure to visible laser light). We propose to realize a beam-writing set-up that could achieve 2D patterning of samples. This method will be used to photo-inscribe different features in the sample (straight waveguides, bends, Y-junctions, etc). Influence of different parameters (fluence, writing wavelength, temperature) in the stability of the inscribed waveguides will be studied, as well as the optimization of the writing parameters in order to obtain single-mode waveguides in the transparency range of chalcogenides. If a stable Y-junction is obtained, optical control of the refractive index (and thus the optical length) over one arm of the combiner will be studied as a way to achieve phase modulation, and limits of reversibility will be assessed.

Mid-infrared optical micro-cavities for sensing applications
Supervisors: Dr. Christian Grillet, Dr. Christelle Monat, Dr. Eric Magi, Dr. David Moss, Prof. Ben Eggleton Contact: Dr. Christian Grillet, 303B, grillet@physics.usyd.edu.au, 9036 9430

The Mid-infrared (Mid-IR) wavelength range - from 2.5 to 20 ?m - is currently experiencing a huge surge in interest for an enormous range of applications that affect almost every aspect of our society, from compact and highly sensitive biological and chemical sensors, imaging, geo-thermal imaging, defense, astronomy, to even sensing for the wine and grape industry. An optical microcavity (a microsphere, a photonic crystal cavity) when properly designed and manufactured can store the light over a very long time potentially leading to high intensities and thus enhancing the light matter interaction which is of particular relevance for optical sensing. In this project, students will create, manufacture and characterise optical micro-cavities designed to operate in the Mid-IR. Testing of the devices will be carried out in the CUDOS clean room nanophotonics laboratory using quantum cascade lasers and an evanescent wave probing technique.

Four-wave mixing in high Q chalcogenide microsphere
Supervisors: Dr. Christian Grillet, Dr. Christelle Monat, Dr. Eric Magi, Dr. David Moss, Prof. Ben Eggleton Contact: Dr. Christian Grillet, 303B, grillet@physics.usyd.edu.au, 9036 9430

A chalcogenide microsphere (a resonator with an almost perfect spheroid shape microns in diameter in a chalcogenide glass), can trap radiation using total internal reflection to force the light to follow a nearly circular path inside the surface of the sphere, making those resonators extremely good at storing light (Qfactor). It results in a drastically enhancement of the light matter interaction, offering the potential for highly efficient nonlinear optical processes. One such process is four-wave mixing (FWM) in which two pump photons annihilate, creating a pair of photons with frequencies situated symmetrically with respect to the pump frequency. Because of the intrinsic high nonlinearity of the chalcogenide, the high Q factor and the small mode volume of the microsphere, it is expected to demonstrate FWM at very low power. In this project, the student will identify the regimes allowing an efficient FWM process to occur and will perform experiment in the CUDOS clean room nanophotonics laboratory using an evanescent wave probing technique.

Optical biomimetics of diatoms
Supervisors: Dr. Christian Grillet, Dr. Christelle Monat, Dr. Rama Hadeiri (school of Biological Sciences), Dr. Gary Rosengarten (UNSW), Prof. Andrew Parker (Oxford)
Contact: Dr. Christian Grillet, 303B, grillet@physics.usyd.edu.au, 9036 9430

Periodic structures are found in nature and may give rise to structural colour as found in beetles and butterflies, whilst others may result in anti-reflection coatings in moth eyes or directional bioluminescence in crustaceans. Some of these materials possess bandgaps, i.e. frequency ranges in which light propagation does not occur through the material. These are of special interest in physics due to their potential as passive waveguides, diffraction elements for solar cells, or photonic crystal lasers. Recently, diatom silica cell walls have been identified as potential photonic-crystal slabs. The student, in a multidisciplinary collaborative effort between biologists and physicists, will aim to recognize and characterize the nanostructures and morphological features that have been optimized by nature and to assess their optical properties. A possible goal is to produce a sensor utilizing the bio-optical properties of the diatom. Experiments will be performed in the CUDOS nanophotonics laboratory and electron micrograph pictures will be taken at EMU.

Profiling and Tunnelling in Slanted Gratings
Supervisors: Ross McPhedran, Martijn de Sterke, Professor Lindsay Botten, University of Technology, Sydney. Contact: Ross McPhedran ross@physics.usyd.edu.au, Martijn de Sterke m.dsterke@Physics.usyd.edu.au

Surface plasmon spectroscopy is an important tool in nanoscience and molecular sensing. Surface plasmons are waves which can exist at an interface between a metal and a dielectric, with their properties being influenced in a measurable way by quite small changes in the properties of the dielectric (leading to the sensing application). Their theory is simple and well understood for planar interfaces between the metal and dielectric, but is much more difficult and interesting when the interface is corrugated. An example of the questions which can arise is when one introduces crests and troughs in the interface, and steadily makes them bigger and bigger. Will the surface plasmon always follow the interface, even though it is being required to follow a longer and longer path? Or will it break away, and start tunneling across crests and troughs?

These questions may seem basic, but their answers are not known, and they require powerful numerical tools to investigate them. We have recently developed a new and elegant way of calculating the properties of a particular type of grating, consisting of slanted slabs of metal sandwiched between dielectric layers. We propose to study the resonances of such gratings as we change the slant, so making the path along the metal-dielectric interface longer and longer. In this way, we expect to be able to persuade the plasmons to switch from profiling to tunnelling. Catching them in the act should lead to some fascinating new physics!

Generation, transmission and regeneration of 1 Tb/s optical signals
Supervisors: Ben Eggleton, Mark Pelusi.
Contact: Ben Eggleton, egg@physics.usyd.edu.au

This project will investigate novel schemes based on nonlinear optics for generating and regenerating ultra-high bit rate data signals for transmission in optical fibre communication systems. The challenge in these systems is that the electronic switching required to detect optical signals is limited to bandwidths of less than 40 Gb/s. Detection and regeneration at higher bit-rates requires principles based on nonlinear optics. This project will utilize the CUDOS Bit-Error-Rate system, a state-of-the art optical transmission test-bed, unique to Australia.

Monitoring noise in ultra-high-bandwidth 1 Tb/s optical transmission systems Supervisors: Ben Eggleton, Mark Pelusi.
Contact: Ben Eggleton, egg@physics.usyd.edu.au

This project will investigate schemes that can monitor noise in ultra-high bandwidth optical communication systems, especially in-band noise on the signal, which limits the distances that data can be transmitted. The problem is that at 1 Tb/s, which involves light pulses that are shorter than a picosecond long, electronics cannot process the information sufficiently fast. CUDOS is pioneering all-optical methods to monitor noise in highspeed optical communication systems. It relies on a nonlinear processes occurring in a nonlinear waveguide, so that very fast fluctuations in the signal, i.e. noise, can be monitored on a slow, and thus cheap, detector. This project will investigate new schemes at 1 Tb/s on our newly established facility. We will analyse simple designs using theory and simulations, which will subsequently be tested on the facility.

Modelling Of Evanescent Coupling Of Light Into Photonic Crystal Slabs
Supervisors: Dr Snjezana Tomljenovic-Hanic, Prof. Martijn de Sterke, and Dr Christian Grillet. Contact: Snjezana Tomljenovic-Hanic Room: 314 E-mail: snjezana@physics.usyd.edu.au Phone: 9351 3953

Photonic crystals rely on coherent scattering of light off large index contrast interfaces to guide light. The advantage of this form of confinement is that tight, narrow structures with very sharp bends can be achieved compared to conventional waveguides. In CUDOS we use evanescent coupling for getting light in and out of these microphotonic structures and we also use this technique to characterize their performance. To do this, a tapered fibre is suspended close enough to the device that the light couples evanescently through the air. The aim of this project is the modelling and optimization of this process. The modelling will make use of two different methods; the first of these is an approximate analytical method that is valid when the nanowire is not too close to the photonic crystal. The second method is numerical, but can model the process to arbitrary accuracy irrespective of the distance between the photonic crystal and nanowire. The combination of these two methods is very powerful indeed. This project can be purely theoretical or can be combined with some experiments.

Optical Fibres

Playing soccer with cells
Supervisors: Sergio Leon-Saval, Maryanne Large
Contact: s.g.leon-saval@usyd.edu.au , m.large@usyd.edu.au

There is an increasing need to be able to manipulate and study matter on a very small scale. One of the most intriguing developments of the last few years has been the use of ”optical tweezers”, which use light to hold and move around very small particles. In this project, we will develop a system for using optical tweezers in a hollow core fibre. The aim to be able to fill the fibre with fluids containing particles, such as cells, and to be able to manipulate their motion along the fibre by using transverse laser beams. This would allow single particles to be isolated and studied. The project would use photonic bandgap fibre, with the transverse beams being at a wavelength that falls outside the bandgap, so that they could be transmitted through the cladding. The success of this playing soccer with cells project will be a building block for the next generation of biophotonic chips.

In-fibre N2 gas laser
Supervisors: Sergio Leon-Saval, Alex Argyros, Maryanne Large
Contact: s.g.leon-saval@usyd.edu.au, a.argyros@usyd.edu.au, m.large@usyd.edu.au

Traditionally optical fibres are associated with diode lasers or fibre lasers. Both are compact and efficient, but also relatively broad-band, and laser transitions are predominantly in the near-IR. Gas lasers are inherently narrow-band, and can be extremely stable in frequency. Hollow-core optical fibre is an ideal partner for these systems as the light interacts only weakly with the material making up the fibre structure. This enables hollowcore fibres to operate in regions where solid material optical fibre would be highly absorbing. We will develop a nitrogen (N2) gas laser inside a inhibited coupling hollow-core fibre guiding at the emitting UV wavelength of 337 nm. A simple Transversely Excited Atmospheric (TEA) pressure laser system scheme will be used to electrically pump the N2 filled hollow-core fibre, in order to achieve lasing. This multidisciplinary project will involve fibre fabrication and the design and realization of the TEA-gas filled fibre laser experimental setup.

Monitoring chemical reactions in optical fibres
Supervisors: Alex Argyros, Mat Todd
Contact: a.argyros@usyd.edu.au, m.todd@chem.usyd.edu.au

Optical detection and monitoring of chemical species is often a powerful and non-destructive way to sense the presence of a particular species or monitor the progress of chemical reactions. What is desired in these cases is a small sample volume, a large overlap with the light and a long interaction length. Although these requirements are often conflicting, they can be met simultaneously if the chemical species fill a hollow-core optical fibre. The light is guided along the fibre through the chemical species filling the hollow core, giving long interactions lengths and strong overlap, whilst only microlitre volumes of solution are required to fill the fibre. The aim of this project is to use polarisation effects to detect the presence of chiral molecules, which rotate the orientation of linearly polarised light. A sensitive detection system is to be assembled and used to monitor the reactions where the products are chiral; the long interaction lengths offered by the fibre should increase the sensitivity of the system. This particular scheme was chosen as the detection of chiral molecules is critical in many biomedical applications, where one handedness of a molecule may be biologically active and the other not.

Chiral Photonics
Supervisor: Alex Argyros
Contact: a.argyros@usyd.edu.au

Despite the long history of optical fibres, chiral materials in optical fibres have scarcely been considered. Chiral materials have handedness - they cannot be superimposed on their mirror image - and result in the rotation of the plane of linearly polarised light (known as optical activity). The aim of this project will be to investigate the possibility of using chiral materials in polymer optical fibres both theoretically and experimentally. Modelling a variety of fibre designs with varying degrees of optical activity will give an insight into what materials and fibres can be useful, and the availability of a polymer synthesis lab and a polymer fibre draw tower will allow specific materials and fibres to be fabricated and characterised.

Surface enhanced Raman spectroscopy on biomolecules
Supervisor: Maryanne Large
Contact: m.large@usyd.edu.au

In this project we will aim to develop highly specialized sensing techniques to allow the detection of trace molecules of biomolecules, such as cardiac markers and DNA sequences by using Surface Enhanced Raman spectroscopy (SERS). The Raman effect gives highly specific molecular information which can act as a ”barcode” for particular materials. It is however a very weak effect, at least a million times weaker than fluorescence. The strength of the Raman signal can be dramatically enhanced in SERS, a process in which the target molecule binds to a coin metal (usually silver or gold). The enhancement can be up to 12 orders of magnitude, and is dominantly due to electric field enhancement effects. Difficulties with SERS are: it reproducibility (it is highly dependent on the exact morphology of the metal surfaces or particles), and the size of the measured signal depends not only on the amount of material there, but also its binding affinity to the metal. This can be particularly problematic in biologically realistic test systems, in which there are multiple components present simultaneously. Together, these difficulties have prevented SERS being used as a diagnostic tool. We will address the in the project by using a fibre based, colloidal approach which is has been shown to produce larger, and more reproducible signals, and we will develop targeted probes to detect specific molecular species. The combination of SERS and a probe based system should allow simultaneous multi-parameter sensing.

Research Projects in Quantum Physics

Mesoscopic Physics

Readout and quantum control of single electrons in nanostructures
Supervisor: Dr David Reilly
Contact: Dr David Reilly, 357, reilly@physics.usyd.edu.au, 9351 8167

Controlling matter at the quantum mechanical level is a key goal of Physics in the 21st Century. With the establishment of a new laboratory in the School of Physics, we will begin a new experiment aimed at the detection and control of single electrons in nanoscale devices at ultra-low temperatures (10 mK). This project will involve many different aspects of experimental physics, including electronics, computer programming and cryogenic techniques. The student will have opportunity to operate state-of-the-art cryogenic apparatus and perform electronic measurements on nanostructures.

Nanoelectronics and Nanofabrication
Supervisor: Dr David Reilly
Contact: Dr David Reilly, 357, reilly@physics.usyd.edu.au, 9351 8167

The focus of this project is the physics and fabrication of nanoscale semiconductor devices. Initial work will be carried out using a suite of advanced fabrication tools at the Semiconductor Nanofabrication Facility (SNF) and Australian National Fabrication Facility (ANFF) at UNSW. The project provides a unique opportunity for the student to gain experience in state-of-the-art techniques for creating electronic devices at the nanoscale.

Hyperpolarized diamond nanoparticles for MRI
Supervisor: Dr David Reilly
Contact: Dr David Reilly, 357, reilly@physics.usyd.edu.au, 9351 8167

Magnetic resonance imaging (MRI) is a highly successful clinical technology used to visualize structures of the human body. In conventional MRI, the nuclear spins of hydrogen atoms are detected to create images based on the density of water in tissue. We are beginning a new project to image diamond nanoparticles using MRI, by first polarizing the spins of the C13 nuclei. These nanoparticles can act as contrast agents opening a variety of in vitro and in vivo imaging applications. This laboratory-based project will expose the student to state-of-the-art instrumentation both at the School of Physics and School of Molecular and Microbial Biosciences.

Quantum Information Theory

Optical Quantum Computing
Supervisor: Dr Stephen Bartlett
Contact: Dr Stephen Bartlett, 317, Bartlett@physics.usyd.edu.au, 9351 3169

LOQC is a scheme to perform quantum computing with photons using linear optical elements to do the quantum gates. This is a very interesting subject at the moment, because the experiments are sufficiently advanced to do basic quantum information processing tasks that are of interest to a theorist. For example, measurement-based quantum computing schemes are being pursued first using photons. We work closely with the experimental LOQC group of Prof White at the University of Queensland, developing new protocols, gates, etc. which they can then do in experiments. A project in this area involves the investigation of schemes to construct massivelyentangled “spin lattices” of photons using LOQC technology, and to use these for measurement-based quantum computing.

Quantum Computing in Cold Spin Lattices
Supervisor: Dr Stephen Bartlett
Contact: Dr Stephen Bartlett, 317, Bartlett@physics.usyd.edu.au, 9351 3169

Quantum computers are potentially much more powerful than the computers we use today, but building a quantum computer is a huge challenge. Most proposals to construct one involve building it from scratch “atom by atom”. What we have shown is that certain materials, when cooled down to a very low temperature, will naturally form a quantum computer on their own. This way, we may be able to get nature to build our quantum computers for us - we just have to find (or synthesize) the right material, then put it in the fridge. This project will be to investigate the zero-temperature quantum phases of a variety of spin lattices, and assess their suitability for quantum computation.
Quantum Control
Supervisor: Dr Stephen Bartlett
Contact: Dr Stephen Bartlett, 317, Bartlett@physics.usyd.edu.au, 9351 3169

Noise usually destroys quantum effects, and if quantum technologies are going to be useful, they need to be robust against noise. In a classical world, complex systems (CD players, airplanes, etc.) are designed to function in noisy environments and with faulty parts by using ”feedback control,” i.e., continuously monitoring the system and correcting its state. (Think of the thermostat in your oven.) Complex quantum systems will also require control, but there is a catch: any measurements that we do on a quantum system will necessarily alter its state uncontrollably. If you look at a quantum system too closely, you completely collapse its state. So we’re developing new methods for feedback control of quantum systems, with a careful balance between acquiring information about the system but not disturbing it too much. A project in this area would be to analyse the fundamental limits imposed by quantum mechanics on some simple operational tasks in quantum theory, such as stabilizing a reference frame or maintaining quantum entanglement.

Foundations of Quantum Physics

Projects in Quantum Foundations
Supervisors: Dr Stephen Bartlett, Dr Owen Maroney, Dr Hans Westman
Contact: Dr Stephen Bartlett, 317, Bartlett@physics.usyd.edu.au, 9351 3169

Quantum foundations concerns the conceptual and mathematical underpinnings of quantum theory. Although new research staff involved in this research area have just arrived in Sydney at the time of publication of this document, we expect that we will be offering Honours projects for 2009. Please come and see us to discuss possible projects. Research in the foundations of quantum theory naturally interfaces with research in quantum information and quantum gravity.
Honours projects – SUPER 61

Research Projects in SUPER Sydney University Physics Education Research

Gravity, ’microgravity’ and freefall
Supervisors: Manjula Sharma and Ian Sefton
Contact: Manjula Sharma, 226E, 9351 2051, m.sharma@physics.usyd.edu.au

Various strategies can be used to explain facets of gravity and freefall. Preliminary phenomenographic analysis has provided a model of how gravity and freefall is understood. In this project you will investigate the effect of prior knowledge on the model. An analysis technique developed in this project can be extended to other topics in physics.

Does multimedia help learn or is it just cool?
Supervisor: Manjula Sharma
Contact: Manjula Sharma, 226E, 9351 2051, m.sharma@physics.usyd.edu.au

Whether multimedia helps learn or just adds ”coolness” is a hotly debated topic. This project will aim to compare multimedia methods of teaching with more standard methods. A specific feature will be identified, multimedia tools designed and implemented.

”Mind Maps” for the more abstract content in second year physics
Supervisor: Manjula Sharma and Christine Lindstrom
Contact: Manjula Sharma, 226E, 9351 2051, m.sharma@physics.usyd.edu.au

Mind Maps providing cohesive overviews of topics have been successfully implemented with first year physics units. Can they be implemented in second year physics where the content is more abstract and in depth? This project will involve designing and implementing Mind Maps and evaluating their success.

Experimentation: essential for learning physics or not?
Supervisors: Manjula Sharma and Joe Khachan
Contact: Manjula Sharma, 226E, 9351 2051, m.sharma@physics.usyd.edu.au
How is learning in the laboratories occurring? What do students learn in laboratory sessions? Can we improve lab learning? These are some questions this project can examine.
Student understanding of basic concepts in Astronomy
Supervisor: John O’Byrne
Contact: John O’Byrne, 311, 9351-3184, j.obyrne@physics.usyd.edu.au

The Astronomy Diagnostic Test (ADT) is a survey developed in the US for undergraduate, non-science majors taking their first astronomy course. It is intended to test students’ knowledge of basic concepts of astronomy. The Southern Hemisphere Edition of the ADT has a small number of minor changes to words and images of the original ADT to permit its use in the southern hemisphere (see www.physics.usyd.edu.au/super/ADT.html).

The Southern Hemisphere Edition of the ADT has been used in the PHYS 1500 Astronomy introductory astronomy unit since 2000 as both a pre- and a post-course quiz. This spans the recent changes to the HSC. Some 2000 students have also been tested again in 2002. The test has also been used at several other universities around Australia.
This project will compare the available data sets, coordinate new data acquisition at other institutions in Australia, and formally validate the test in the Australian context.
Research Projects in Theoretical Physics

Stock market crashes and solar flares
Supervisor: Dr Mike Wheatland
Contact: Mike Wheatland, 463, m.wheatland@physics.usyd.edu.au, 9351 5965

Stock markets exhibit regular growth together with spectacular drops (crashes), and this time variation may be modelled using stochastic differential equations incorporating “jump transitions.” Similarly, active regions on the Sun (regions around sunspots) increase their magnetic energy gradually in time, and then lose energy suddenly and unexpectedly when a solar flare occurs. Stochastic jump transition models appropriate for the stock market also describe the occurrence of solar flares, and may be exploited for improved solar flare prediction. This project addresses Monte Carlo modelling of stochastic differential equations applicable to stock markets and flares. A time-varying model for an emerging flaring active region will be developed. There is substantial scope in the project for theory, computational modelling, and visualisation. Numerical skills in stochastic calculus are highly valuable for those interested in a career in the financial markets.

Bayesian prediction of solar flares
Supervisor: Dr Mike Wheatland
Contact: Mike Wheatland, 463, m.wheatland@physics.usyd.edu.au, 9351 5965

Solar flares are magnetic explosions in the solar atmosphere that affect our local “space weather,” producing energetic particles in the local space environment which present radiation risks to astronauts and passengers on polar flights. Space weather effects drive the need for solar flare prediction. However, flare physics is not well understood and there are no deterministic methods of prediction. A Bayesian method of whole-Sun flare prediction has been developed, which uses only the observed recent history of flaring, and knowledge of solar flare statistics. The method neglects the wealth of observational factors known to correlate with flaring (predictors), but still out-performs the method used by the US National Oceanic and Atmospheric Administration in predicting large flares (Wheatland 2005). In this project the method will be generalised to incorporate additional predictors, using the framework of Bayesian predictive discrimination. The project involves a mix of data analysis, theory, and numerical implementation of methods.
M.S. Wheatland, A statistical solar flare forecast method, Space Weather Vol. 3, No. 7, S07003 doi:10.1029/2004SW000131 (2005)
3-D computational modelling of the Sun’s magnetised atmosphere
Supervisor: Dr Mike Wheatland
Contact: Mike Wheatland, 463, m.wheatland@physics.usyd.edu.au, 9351 5965

The Sun’s outer atmosphere, the solar corona, is a magnetised plasma exhibiting dynamic and complex behaviour. Solar flares are dramatic explosions in the corona involving liberation of stored magnetic energy. To better understand flares we need to be able to model the magnetic field in the corona from available observations. This project involves developing a computational method for 3-D magnetohydrostatic modelling of coronal fields (time-independent modelling involving a balance of magnetic, gravitational, and gas pressure forces) based on a method described by Grad and Rubin in 1958. The Grad-Rubin approach has already been successfully developed for modelling including only magnetic forces (Wheatland 2007), but the results in application to solar data have proven unsatisfactory because of the importance of non-magnetic forces. In this project the Grad-Rubin method will be implemented including pressure and gravity, and applied to available test cases. The project offers scope for theory, large-scale computation, including parallel computation, and visualisation.
M.S. Wheatland, Calculating and Testing Nonlinear Force-Free Fields Solar Physics 245, 251-262 (2007)
Pair modes
Supervisors: Don Melrose, Sergey Vladimirov, Roman Kompaneets
Contact: Don Melrose melrose@physics.usyd.edu.au, 9351 4234

Pair modes are an exotic form of plasma waves that have been identifies as solutions of the dispersion equation for a magnetized, relativistic, degenerate electron gas. A pair modes may be interpreted as a wave-like solution associated with virtual electron-positron pairs. In particular, their frequency (times Planck’s constant) is similar to the rest energy of a pair.

We speculate that pair modes should exist in a solid state plasma associated with the virtual production of electron-hole pairs. This speculation is based on the assumption that the annihilation of an electron-hole pair is analogous to the annihilation of an electron-positron pair, and hence that the dispersion associated with electron-hole pairs should be analogous to that associated with electron-positron pairs.

This project is to explore our speculation in detail. It will involve formulating a new theory: the theory of wave dispersion in an electron-hole plasma. A major part of the project will be understanding the (rather scant) literature on pair modes and their interpretation, and adapting this to the electron-hole case.
Any student interested in this project should be aware that it is high risk/high gain. Our speculation may prove to be incorrect or unfruitful, or it may lead to a potentially important new line of research.
Pulsars: the closed magnetosphere
Supervisors: Don Melrose, Qinghuan Luo
Contact: Don Melrose melrose@physics.usyd.edu.au, 9351 4234

Pulsars are strongly magnetized, rapidly rotating neutron stars, in three broad classes: ordinary pulsars, millisecond (recycled) pulsars, and magnetars. The pulsed radio and high emission come from polar-cap regions where the magnetic field lines are open, in the sense that the field lines extend beyond the light cylinder, into the region called the pulsar wind. There is also a region of the magnetosphere where the field lines are closed. The ratio of the open to closed regions decreases as either the strength of the magnetic field or the pulsar period increases; in particular, the ratio of open to closed is tiny in magnetars. The closed field region has been largely ignored until recently. It is of particular interest in connection with emission coming to the observer from the back side of the pulsar, and passing through the closed field region.

This project involves comparing and contrasting models for the closed magnetosphere in pulsars with wellestablished models for processes in the Earth’s magnetosphere. In both cases there is an external sources of plasma (inward diffusion from the pulsar and solar winds, respectively) with the particles trapped in a magnetic bottle. Trapped particles are lost by scattering into the loss cone. This is due to scattering by waves in the terrestrial case, and analogous processes need to be explored in the pulsar case. An important difference is that gyromagnetic losses (due to synchrotron and cyclotron emission) can play a dominant role in the pulsar case, but are unimportant in the terrestrial case.
This project will involve mainly analytic modelling, with an emphasis on plasma instabilities and gyromagnetic emission in a superstrong magnetic field.
Nonthermal X-ray emission from magnetars
Supervisors: Qinghuan Luo, Don Melrose
Contact: Qinghuan Luo, 455, luo@physics.usyd.edu.au, 9351 2934

Soft gamma repeaters (SGRs) and anomalous X-ray pulsar (AXPs) are high-energy transients, emitting both thermal and nonthermal X-rays. SGRs and AXPs are believed to be magnetars which are rotating neutron stars with extremely strong magnetic fields (∼ 10^15 G). Radiation processes in magnetars are gernally thought to be powered by decay of superstrong magnetic fields. While the thermal X-rays can be modeled as thermal emission from the localized hot surface, the specific process that produces nonthermal X-rays is not well understood. Observations suggest that the nonthermal component originates in the magnetar magnetosphere. The project will investigate inverse Compton scattering by relativistic electrons (or positrons) in the magnetar’s superstrong magnetic field and its relevance for the nonthermal emission. The project will focus on the scattering in the cyclotron resonance regime where production of nonthermal X-rays can be very efficient. The project will involve analytical modelling of nonthermal spectra that can be compared with observations.