Master of Research
Macquarie University has adopted a new postgraduate degree structure, making it the first Australian university to fully align with European, North American and Asian qualifications. With greater international recognition for their qualifications, graduates of the new degree will enjoy enhanced employment opportunities and pathways to further study overseas. Consistent with the well-known ‘Bologna model’, the two-year full-time Master of Research (MRes) will replace honours as the main pathway to a Doctor of Philosophy (PhD) and Master of Philosophy (MPhil).
The degree is a two year degree made up of a total of 64 credit points. The first year is 32 credit points of advanced course work, the second year is predominately research culminating in a thesis.
Enquiries can be directed to the Physics and Astronomy MRes Advisor: A/Prof Alexei Gilchrist
Please see the following pages for all the details:
2015 MRes Year 1
The first year of BPhil/MRes is primarily coursework. In physics, all the units in the first semester are compulsory and cover essential skills and knowledge.
|Unit Code||Unit Name|
|All the units in semester 1 are compulsory:|
|PHYS700||Research Frontiers in Physics and Astronomy 1||Unit Details|
|PHYS701||Mathematical Methods in Physics||Unit Details|
|PHYS702||Statistical Physics||Unit Details|
|PHYS703||Computational Science||Unit Details|
|Unit Code||Unit Name|
|The centrally taught MRES700 unit is compulsory:|
|MRES700||Research Communications||Unit Details|
|Selected three more units from physics or other departments (subject to approval):|
|PHYS714||Quantum Information and Technology||Unit Details|
|ASTR707||Advanced Astrophysics||Unit Details|
|ASTR708||Introduction to Particle Physics and Cosmology||Unit Details|
|PHTN702||Advanced Photonics||Unit Details|
|PHYS798||Physics and Astronomy Special Topic 1||Unit Details|
|PHYS799||Physics and Astronomy Special Topic 2||Unit Details|
Fees and Financial Support
Please see the following for details:
2015 MRes Year 2
The second year of MRes is structured around five activities: Research Frontiers 2, literature review, research methods, research planning, and thethesis. Year two will be predominantly assessed on the thesis (90%) with a contribution from Research Frontiers 2 (10%). Satisfactory performance in the other activities is required but they do not acquire a separate formal mark.
|Schedule of tasks for year two of the physics MRes.|
Read literature; research workshops
Mandatory faculty sessions:
1. Literature Session – 19 January (1/2 day)
2. Planning Session – 23 January (time TBA)
3. Writing Session – 21 January (10-12) (for students entering directly into Y2 only)
|February||Read literature; participate in journal club; research workshops|
Read literature; participate in journal club; research workshops
DUE: end of March – project proposal presentation to research groups
DUE: end of March – draft research project plan
Research workshops; read literature; journal club to mid April
DUE: mid April – big questions research essay
DUE: end of April – detailed MRes research plan
DUE: mid May – draft literature review
DUE: end of May – literature review
|June||Conduct research project and write thesis|
|July||Conduct research project and write thesis|
|August||Conduct research project and write thesis|
Conduct research project and write thesis
DUE: end of September – draft thesis
Finalise thesis and extend research proposal to PhD plan.
DUE: 9 October – thesis submission
DUE: end of October – detailed PhD research plan
Activity 1: Research Frontiers 2
This activity is designed to guide students in taking a critical look at their field as a whole. Students will examine more closely the frontiers of their chosen research area answering such questions as “What are the most important recent findings? What are the big open questions? Who are the leaders in the field?” While answering these questions students will learn how to critically assess research claims.
Each week, students are expected to find and read papers from their research area and be prepared to critically discuss the articles. The class will meet with the lecturer every week, up to April, and at the meeting some students will be selected to present their chosen articles, with the ensuing guided discussions instructing the students on how to assess research papers, identify the key results, understand why they are claimed to be significant, and see how the results are justified and presented. Students will be expected to present at least two such articles, and to use a number of these articles for their written report. Guidance in analysing and discussing the journal articles will be provided by the lecturers, but students are expected to select their own articles.
Activity 2: Literature Review
Students will attend introductory classes explaining the review of scholarly literature and its relationship to their individual research project (2-4 sessions). Workshops will also be held on electronic databases, journal citations, navigating citation chains and analysing journal articles.
Students will then do a significant preliminary survey of the literature relevant to their proposed research area and of a length of approximately 5,000 words. Progress and any issues arising are to be discussed with the supervisory panel weekly.
A significant draft is required by middle of May and each student’s Supervisory Panel will give relevant advice to the student. The final review is due end of May and is expected to be incorporated into the thesis.
Activity 3: Research Methods
As part of the degree requirements, second-year MRes students are required to complete a series of research methods activities. Some of these activities are of a technical nature specific to your project. The others are of a general, professional training style and will be delivered through the Q2Q program.
To this end, second-year MRes students are required to complete 3 modules in that program, in addition to “Developing self-sufficiency through LaTeX”.
Note that “The PhD thesis” module is not appropriate for MRes students.
Activity 4: Research Planning
In addition to centrally taught sessions on project management, students are required to develop a plan to tackle their main research question. A draft research project plan will be completed for the MRes project by end of March including extension to a larger 3 year PhD project. Students will receive feedback on the research plan and possible amendments. Note that the Supervisory Panel members are expected to be closely involved in the research planning.
The students will present their project proposals to their research centres in 20 minute presentations towards the end of March. Department members are invited to attend all presentations. These presentations are assessed and reviewed by the supervisory panels with feedback to the students. If a research plan is deemed unsatisfactory, the student will again be counselled to amend the plan.
The detailed MRes research plan is due end of April, for a project of one half year duration. The MRes research plan will include the aims of the project, background and significance of the project, proposed methods, timeline and budget, and the expected outcomes. The plan should indicate the proposed path to a PhD project of 3 years duration.
A detailed PhD research plan is due at the end of October, (coinciding with the APA application deadline). This will include the aims of the wider project, background and significance of the project, proposed methods, timeline and budget, and some indication of expected outcomes.
Activity 5: Thesis
MRes students will complete research project in order to demonstrate individual research capability to conduct Major (PhD-scale) Research Project, producing a thesis equivalent to 15,000-20,000 words.
MRes students will have a supervisory panel of at least two supervisors from the beginning of the project. Note that the pattern of supervision may change as the project evolves, and one of the supervisors may take a lead role or both may participate jointly. It is also possible that additional supervisors (eg offsite) may be assigned if needed.
2015 MRes Projects
In the section below, you’ll find links to all the MRes projects on offer in 2015. These are available to both students in the current first year of the MRes course, and to Honours graduates from other universities interested in completing the second year of the MRes, perhaps as preparation for a Macquarie PhD.
Procedure for current Macquarie MRes students:
You should take time to look through the list of projects carefully. Identify those which sound interesting to you and then contact the lead supervisor directly. You should arrange to visit them to learn more about the project. Don’t be shy. Staff members will be very keen to pitch their projects. Make sure to approach this process with an open mind. Don’t be too quick to decide what branch of study is most interesting to you. Make sure to visit a few potential supervisors and find out their personal approach to supervision. Once you’ve identified a project and supervisor, and obtained their agreement, send an email to Alexei. Make sure to copy your chosen supervisor on that email. That’s all!
Procedure for students wishing to join Macquarie:
If you think you might be interested in joining the second year of the MRes after completing Honours elsewhere, then great! We’re always looking for new students. Take a look through all the projects and identify those that are interesting. Contact the supervisors involved and have some discussions by telephone or skype to see if the project is a good fit for you. You should also contact MRes convenor Alexei Gilchrist, to get a broader picture of how the program works.
The projects are broadly divided into three areas: Astronomy & Astrophysics, Photonics & Condensed Matter, and Quantum Physics. Remember that much of our work is interdisciplinary, so a project of interest to you may be listed under a section you don’t expect.
Projects in Astronomy and Astrophysics
Extreme Imaging with the Huntsman Telephoto Array
A new astronomical imaging system has been designed that uses high-quality Canon lenses to detect ultra-faint light in nearby galaxies. This allows us to detect previously inaccessible signatures of how distant galaxies grow through time. The imaging system will consist of an array of +10 of these Canon lenses that work together to produce ultra-faint images of nearby galaxies. We are now testing a pilot system named the Huntsman Telephoto Eye. You can see the Eye and our initial data on twitter at: #HuntsmanEye. This MRes project will be focused on setting up the initial remote observing software/program and conducting image processing with the data we have taken so far.
Extension scope:Imaging datasets will only take a few weeks to observe, so there will be ample opportunity for cutting-edge scientific projects in the near future. Please contact the supervisors for more details.
What’s the Matter with Galaxies?
How heavy is a galaxy? In answering this seemingly simple question, you will delve into the mysterious world of measuring mass in galaxies. Using integral field spectroscopy observations, you will learn how to apply a range of advanced modelling techniques to measure how much mass is in a galaxy, and how is it distributed. You will have to consider the presence of dark matter, black holes, and the role of the stellar initial mass function as you apply dynamical and stellar population models to your own unique data set. This project has a mixture of theory and observations.
1) Extending the observational campaign to include more galaxies;
2) Developing dynamical modelling techniques further;
3) More sophisticated application of stellar population models.
Galaxy Archeology with Massive IFU Surveys
We are on the cusp of a revolution in spatially-resolved studies of galaxies. Multi-IFU fibre bundle instruments are providing maps for thousands of objects, eventually giving 100,000 galaxies in the coming years. This project will use new data from such surveys to explore their potential for mapping star formation histories, thus deriving the ‘when’ and ‘where’ of star formation in galaxies, and yielding new insights into galaxy formation and evolution. This project is based on applying stellar population models to already calibrated data.
The surveys that provide the data for this project are just starting. There is plenty scope to expand this to larger, more complex galaxy samples, and explore deeper involvement with these surveys.
Accretion onto the supermassive black hole Sgr A*
The bright radio source Sagittarius A* at the Galactic Centre is a black hole with a mass 4 million times that of the sun. Radio, infrared and x-ray emission from Sgr A* has accordingly been subject to intense scrutiny over the past decade. Detailed simulations have been applied to the innermost portion of the accretion flow, but these do not have sufficient dynamic range to address the process by which captured gas spirals in from 0.5 light years to within a few light hours of the event horizon.
This project aims to construct analytic and semi-analytic models of the dynamics of this neglected portion of the accretion flow, with a view to determining the rate of delivery of mass and angular momentum to the inner accretion disc. The radio and X-ray emission from the gas will be modelled with the aim of using observational data to explore the transition from million degree coronal plasma to a strongly magnetised relativistic plasma that the gas undergoes as it falls in and circularises close to the event horizon.
The project lends itself to a number of possible extensions, including applications to supermassive black holes in the nuclei of external galaxies, studies of the interaction of Sgr A* with its surroundings in the inner few parsec of the accretion flow, and theoretical studies of the quiescent and flaring emission from Sgr A*.
About half of solar like stars are born in binary and multiple systems. Of those a substantial fraction are binaries so compact that at some point in their lives an interaction is inevitable. An example of such interactions are powerful explosions we know as supernovae type Ia. Today, large surveys are discovering myriads of new phenomena that may be attributed to such stellar interactions, primarily stellar outbursts and explosions.The types of outbursts are so diverse that interpreting them will require understanding the physics of what happens when two stars interact, including what happens when a star engulfs its planetary system.
In this project, the student will analyse the output of a series of simulations where stars and planets are swallowed by a growing giant. To do so the student will attain a basic mastery of python and work with pre-prepared scripts designed to determine whether, for example, the mother star is broken apart by the companion, whether the companion escapes, or whether a light outburst should be detected. These are all fundamental steps to interpret outburst observations.
Over a 3 year PhD program, the project could be extended to a broader range of interactions, or multiple body encounters. The student will run simulations with our grid code or an alternative code and become proficient in computational astrophysics.
Jets and Magnetic Fields in Evolved Stars
When stars age, they grow in size. In so doing they tend to interact with their stellar companions or even with their planetary systems. When this happens we usually witness light outbursts and, over time, a nebula may develop. These nebulae tend to have non symmetric but otherwise organised, and often spectacular shapes. The nebula is made of gas ejected by the binary star during the interaction. The binary, or planetary system, gives an axis of symmetry to the ejection, but it is another agent, that is the ultimate artist responsible for the shapes. Magnetic fields. The mechanism by which magnetic fields are born and later partake in imparting nebular shapes remains almost completely unknown.
In this project, the student will begin by identifying a list of nebulae for which the magnetic field is suspected but not measured. Once this list is in hand, radio archival data from a range of observatories will be searched to find available data. The aim is to find data that can point to the presence, strength and organisation of a possible magnetic field that is responsible for the complex nebular shapes observed.
Over a 3 year PhD program, the project could be extended to use modern, more sophisticated and tailored observations to launch a coordinated program able to find magnetic fields systematically. Ultimately observations will be planned for some of the most powerful telescopes on Earth: the Australian Square Kilometre Array Pathfinder and the Atacama Large Millimetre Array.
Projects in Photonics and Condensed Matter
Cerium Lasers: Ultraviolet, Ultrafast and Ultracool
Cerium lasers are efficient solid state lasers that operate directly in the ultraviolet. In the LASER Group of MQ Photonics, we have already demonstrated ultrafast operation of these lasers, producing picosecond pulses in the ultraviolet for the first time. Yet these lasers have the potential to directly emit pulses from femtoseconds down into the attosecond domain, shorter than any other laser system. The challenge now is to push these sources to their limits, to bring about a revolution in ultraviolet, ultrafast laser technology. In this project we will explore techniques to take our current picosecond cerium lasers and push them into the femtosecond domain. This will involve hands-on experiments in the LASER Group laboratory as well undertaking supporting theoretical analysis. The first steps will be to explore pulse compression of picosecond cerium lasers and characterisation of these pulses. This work is funded by an ARC Discovery Grant.
This MRes project is an important step that can smoothly lead into a more expansive PhD project in femtosecond and possible attosecond cerium lasers. The key will be to incorporate dispersion compensation in the laser and more advanced forms of pulse compression.
Topological Beams: Twists and Turns
We have shown that visible Raman supercontinuum generation from nanosecond microchip lasers in multimode optical fibres can produce an intriguing variety of colourful beam topologies. Topologies already observed include doughnut beams with extremely high orbital angular momentum, well defined high order single spatial modes through to complex patterns of coloured rings. We have also shown how the vortex beams can be deformed into tightly wound optical spirals with characteristics unlike any other optical source. These sources have potential applications ranging from micromachining, optical tweezers, driving micro-motors and micro-pumps through to more fundamental applications of single photons with very high orbital angular momentum. In this MRes project you will explore the formation of high orbital angular momentum beams and their spatial coherence characteristics. Questions to be considered are: what are the mechanisms that determine the spatial and spectral structures of these beams? What determines their coherence characteristics? Can we produce pure coherent states with specific values of the orbital angular momentum (e.g. l = 600). The project will also include exploring interferometric techniques for characterising vortex beams including rotating shearing interferometry.
This MRes project can be extended into a PhD project in many different directions depending on your interests. Avenues for further exploration include development and applications of angular shearing interferometry, materials processing applications with patterned vortex and spiral beams, quantum optical applications of high orbital angular momentum beams.
Integrated Microphotonics and Applications
Research Field: Photonics, Quantum physics, Astronomy, Astrophysics or Astrophotonics, Materials science
Supervisors: Prof Michael Withford, A/Prof Michael Steel and Dr Alex Fuerbach
The ARC Centre of Excellence CUDOS (Macquarie) develops novel integrated photonic devices (theory and experiment) and explores their diverse applications. In 2014 we hosted two distinct MRes projects, one developing complex astrophotonic chips, the other utilising existing optical chips to explore laser nerve stimulation with our collaborators in the University Hospital. These projects were tailor to match the interests and goals of the students. In 2015 we are offering projects in the fields of:
- Quantum photonics
- 3D microphotonics
Students are encouraged to contact us and discuss their interests related to the above themes. A background in photonics is not essential.
The projects are designed to serve as a springboard to PhD research projects in either astrophotonics, quantum photonics, medical photonics and related optics themes.
Optical trapping and Levitation of nanoparticles
In the 80’s Ashkin proved for the first time that the Physics of the Star Wars’ “tractor beam” was possible. Using electromagnetic radiation (an optical beam) he managed to capture a small particle and move it around without physically touching the particle. Since then, there has been an explosion of applications of this technique, which has led to a Nobel prize in physics and a whole new industry in biotechnology. Nevertheless, the possibility of trapping small particles in vacuum (optical levitation) is still a battleground for physicists. In this project we will set-up an experiment to trap and manipulate small particles in water, air and vacuum. We will use a continuous wave laser and a nanopositioner in order to beat the gravitation and van der Waal’s forces locking the particles to the substrates. We will explore different experimental techniques to increase the optical forces to levitate smaller and smaller dielectric particles.
This project is part of an ambitious project to observe quantum effects in dielectric particles, by isolating them from any decoherence due to the environment. Over a 3 year PhD program, the candidate will have the opportunity to use these techniques to cool the dielectric particle to ultralow temperatures and observe the quantum properties of a macroscopic object.
The Fibre Whisperer: Engineering the Light-Sound Interaction in Nanoprocessed Optical Fibres
We tend to think of light and sound as existing in very different domains, but opto-acoustic interactions in nano-photonics are a very active area of study. Indeed stimulated Brillouin scattering (SBS), the nonlinear coupling between optical and acoustic waves in waveguides, is the strongest of all optical nonlinearities. For many years, SBS was largely a nuisance, but it is now seen as a gateway to many applications: narrow linewidth filters for microwave photonics (“radio-over-fibre”), novel compact lasers, `True Time Delay’ radar for defence, and integrated optical isolators (“diodes for light”). One of the most attractive aspects of SBS is the ability to simtaneously engineer the photonic and “phononic” (acoustic wave) propagation by designing nano-scale structures that influence the photons or phonons or both. In this project, we will theoretically explore the modification of acoustic wave propagation in optical fibres by the creation of sub-micron scale spatial voids using femtosecond laser processing. By careful design of periodic and aperiodic structures within the fibre we expect to be able to induce phononic band gaps and other alterations to the acoustic propagation. We can then calculate the expected change in the SBS interaction and determine how to exploit it for applications such as Brillouin fibre lasers. The project would involve a mix of analytic treatments using Hamiltonian and coupled mode formalisms, and numerical modelling using sophisticated tools. The project is part of a major initiative in SBS involving researchers at Macquarie, UTS and the University of Sydney. A project with an experimental focus is also possible.
A PhD project could extend in many directions: fabrication and characterisation of the structures using laser processing systems, development of a more sophisticated general formalism for SBS interactions, extension of these ideas to nanophotonic systems, or a combination of all of these.
High-Q Mechanical Resonators
The field of optomechanics – where one studies the interaction of light forces with mechanical moving objects has recently enjoyed a huge surge of interest. Much of the reason for this interest comes from the desire to explore new physical systems where novel physical effects appear but also to build exquisitely precise sensors for magnetic/electric etc fields. To reach exciting new regions of physics and possible high precision sensing one seeks to develop mechanical motional oscillators which possess as little damping as possible i.e. with high motional Q-uality factors. One way to achieve this is via mechanical resonators which have no mechanical contact with their surroundings e.g. are levitated/trapped in space. The typical method to achieve this is via optical tweezers but such trapping comes with some difficulties relating to laser noise possibly heating the motion of the mechanical oscillator. In this project we will take a different route – using no light we will develop passive magnetic trapping of particles in ultra-high-vacuum. These particles will be stably trapped and oscillate in space. The goal of this project will be towards achieving ultra-high motional Q-uality factors and high motional frequencies for these magneto-mechanical oscillators and to determine the feasibility to use such oscillators for sensitive metrology. The project will be primarily experimental in nature but will also require some theory/numerics to develop/fit the theory to the experiment.
This project probes an exciting new area of meso/nanoscopic control – magneto-mechanical trapped systems. This new field of research has a wealth of novel phenomena to be explored, understood and utilised for a variety of purposes eg. ultra-sensitive sensing. It is expected that there are extensions of this project to multiple PhD projects also with the potential for national/international collaborations.
Nonlinear Laser Dynamics
Research Field: Lasers, Photonics, Nonlinear Science
Supervisors: Prof. Deb Kane, Dr Josh Toomey
Contact: firstname.lastname@example.org, E6B 2.701
A range of projects topics are available in experimental nonlinear laser dynamics. External funding support for the area is currently provided by a SIEF Round 4 project grant joint between NICTA, Sirca, Macquarie University and Sydney University. Available projects range from fundamental investigations of longitudinal mode dynamics in semiconductor lasers to establishing new nonlinear laser systems to generate time series datasets of targeted complexity values.
All the possible topics are readily extended to PhD projects that can build track record for all foreseeable physics futures with appropriate engagement. International collaboration can be an integral part of these PhD projects. The group has several active international collaborations and joint PhD projects with overseas universities are also possible.
Laser Supported Techniques for Conservation in Art and Cultural Heritage
Opportunities exist for students interested to contribute to research using laser conservation techniques to inform and assist conservation of art and cultural heritage objects. A range of projects building on prior research that has been published are available. There are a range of serious conservation issues for Aboriginal bark paintings, in particular, that new, innovative laser approaches can be researched to address. The Australian Museum is a research partner in this research.
The opportunity in this area is very large. Several PhD projects are possible.
Optical Surface Profiling of Active Optoelectronic Devices
Research Field: Photonics
Supervisors: Prof. Deb Kane, Dr Doug Little, Dr Josh Toomey
Contact: email@example.com, E6B 2.701
Research new optical surface profiling experimental techniques for application to active optoelectronic devices. The project will use the through transmissive media capability of the state-of-the- art NT9800 optical surface profiler facility established in 2011 with an ARC LIEF Grant. The type of measurements that are planned have never been undertaken before. This project combines two research topics in which Macquarie Physics is currently undertaking world class research – fundamental laser physics of semiconductor lasers and optical surface profiling. The student will build broad experimental capability with sophisticated experimental techniques and develop theoretical understanding of the physics underpinning the project in order to perform thorough and high level analysis and interpretation of project data. This project will suit a student looking for an opportunity to develop broad and multiple research capabilities in a well supported group environment.
The project is readily extendable to a PhD by inclusion of dynamic MEMS and/or extending the through transmissive medium (TTM) capability to other challenging samples of physics interest.
Photonics of Certain Spider Orb Webs
Opportunities exist for students to contribute to research on the photonics and optics of certain spider orb webs. Considering orb webs constructed in bright environments as an optical as well as a mechanical device is informing new hypotheses on their function. The optical materials of this subset of webs are highly birefringent, highly dispersive, have high optical nonlinearity and represent a natural self assembled optical material which is nanocomposite in form. This research is currently being advanced by an externally funded ARC Discovery Project. Available projects range from theoretical simulation of optical elements from the webs through to micro- and nano-scale microscopy with an emphasis on understanding the physics of the microscopy techniques in interpreting physical characteristics from microscopy images.
The full range of possible topics are readily scalable to PhD projects.
Fabrication and characterization of a planar waveguide diamond laser
Amongst all laser crystals, synthetic diamond has been found to be outstanding in almost all categories of performance including power, efficiency, and wavelength range, across cw-to-ultrafast temporal formats. Many aspects of performance, such as wavelength range and power handling capability, may be further enhanced by tightly guiding the light through diamond in an optical waveguide. Methods for fabricating waveguides in single crystal diamond are challenging, yet we at Macquarie have pioneered a technique for fabricating low-loss waveguides in planar format. This project will further refine the technique to enable the first detailed characterization of a chip-scale diamond Raman laser.
By exploiting the planar diamond waveguide concept, an extended project will be well placed to demonstrate, model and understand a new class of ultra-bright micro-scale lasers.
Functionalizing diamond chips using novel 2-photon UV etching
Diamond has a range of extreme properties making it of intense interest in fields as diverse as quantum science, optics and biochemistry. We have recently pioneered laser-written techniques to controllably alter the elemental composition of the single atomic terminating layer present on the surface and, which is critical in determining many of its physical properties. This project seeks to extend this research to develop techniques for diversifying the range of terminations and patterns that can be produced. The aim is to demonstrate a versatile processing approach for rapid prototyping of advanced micro and nano-resolution functionalized surfaces.
The project will provide an excellent basis for a broader PhD research program in directions as diverse as photonic metamaterials, fast surface transistors and quantum devices.
Enhancing radiotherapy with nanoparticles
This one year project hosted by the ARC Centre of Excellence in Nanoscale Biophotonics will explore the prospect of effective cancer radiotherapy at a reduced radiation dose by using nanoparticles.
Inorganic and noble metal nanoparticles are made of heavier atoms than the human body and they interact more strongly with ionising radiation. This means that the deposition of energy per unit length is higher and hence the effects on biological systems should be more intense. Early research in this field focussed on radiosensitization, where nanoparticles have been used to magnify cytotoxic effects of radiation. This project will focus on nanoparticles in conjunction with photodynamic therapy (PDT), where conjugated photosensitizers are used to produce singlet oxygen which is harmful to cells. At Macquarie we have been able to show that scintillating CaF2 nanoparticles conjugated to verteprofin photosensitzer and triggered by X-rays produce enough visible photons to be able to generate meaningful quantities of singlet oxygen sufficient to kill the cells (>Niedre dose). Current research focuses on gold nanoparticles also conjugated to verteprofin where we expect an electron transfer to be the main mechanism of singlet oxygen generation. It is yet to be established whether this process is efficient enough to be useful.
Several questions which need to be answered in this area:
1) Do conjugated photosensitizers with nanoparticles reduce the required radiation dose compared with using radiation with nanoparticles only, or compared with radiation only.
2) Does this effectiveness depend on the characteristics of radiation.
3) What type of generally biocompatible nanoparticles are most effective.
Answers to these questions will be partly by numerical simulation of the interaction of radiation with nanoparticles and partly by experimentation in the area of chemical physics We will use the gamma knife available at Macquarie University Hospital, in partnership with Dr Michael Grace from Genesis Cancer Care.
Extension scope: PhD projects continuing this line of inquiry will combine radiation-triggered nanoparticles with molecular targeting of key cellular compartments. This work will be done in partnership with Professor Brian Wilson from the University of Toronto with whom we will be aiming to develop novel therapies for pancreatic cancer. Professor Wilson is a worldwide authority in PDT monitoring and Biophotonics.
Hyperspectral technology for immune cell characterisation
This one year project hosted by the ARC Centre of Excellence in Nanoscale Biophotonics will use hyperspectral imaging technology to characterise immune cells interacting with nanoparticles. Hyperspectral technology quantifies subtle features of cell colour. It is implemented on a fluorescent or laser scanning confocal microscope. It uses specialised computer controlled light sources and custom-made computer programs to collect data and analyse images. Most of this code is already written but the student will be able to make their own contribution. They will also be able to contribute to the building of the light sources. They will characterise cells interacting with nanoparticles and their controls without nanoparticles. They will extract various features if individual cells and population properties. Careful analysis and decomposition of colours of cell populations will enable detailed quantification of aspects of cellular metabolism and how this metabolism affects the destiny of immune cells in the body in viral diseases.
Ref: Therapeutic Inflammatory Monocyte Modulation Using Immune-Modifying Microparticles, Getts et al., Science Translational Medicine 15 January 2014:Vol. 6, Issue 219, p. 219ra7, DOI: 10.1126/scitranslmed.3007563
Extension scope: This project has multiple facets with respect to instrumentation development, information technology as well as endless scope for groundbreaking insights into immunity, working in partnership with a leading edge expert, Professor Nick King form the University of Sydney.
Projects in Quantum Physics
Quantum and classical free space communication with twisted beams
Global network communications are reaching their capacity limit. Therefore, novel ideas regarding how to encode and send information need to be explored. Some of those ideas are appearing from very fundamental concepts of electromagnetic fields. In particular, the property of electromagnetic fields to carry angular momentum and transfer it to material particles has been used to encode information and transmit it over free-space and fibre links. Interestingly, angular momentum modes can also be used in quantum communications in order to increase the information carried by each photon and make quantum cryptography schemes resilient to noise. Angular momentum beams typically have a peculiar doughnut like profile, like a ring of light. Moreover, their phase front is tilted giving rise to a spiral surface, hence the appellative of “twisted beams”. On the other hand, they are easy to create and measure using computer generated holograms or other diffractive elements. In this project, the candidate will study the classical and quantum properties of these interesting electromagnetic modes. The candidate will use a set of two telescopes as emitter and receiver and will establish a free-space link to study the propagation of these modes through the atmosphere. The free-space link will then be used as a classical and quantum communication channel to transmit information over the atmosphere.
This project is integrated in a much larger line of research where the research team will be integrating sources of angular momentum modes in telescopes for communication purposes, but also in order to observe and analyse certain astronomical objects under the lens of this new degree of freedom. Thus, this project will be naturally extended into a PhD project, where the candidate will aim to produce more compact angular momentum analyzers and study with them the rotation of certain astronomical objects such as stars or galaxies.
How to Make a Movie of a 3D Quantum Walk
Quantum walks are one of the most vibrant areas of contemporary quantum information science. Photons wandering across a waveguide lattice can produce interesting entangled states, explore new regimes for Anderson localisation due to disorder and perform aspects of quantum computing. In integrated optics however, the photon walking happens inside a chip and we can only measure the final state. This makes it very difficult to observe the development of non-classical correlations and other signals of entanglement. Recently, we proposed a new approach to quantum walks in an integrated circuit with two appealing features: a 3D waveguide arrangement allows novel correlations in exotic structures such as the “Mobius Strip” geometry, and a set of in-built input/output couplers allows the photons to leak out randomly over the course of the walk. By measuring two photon correlations repeatedly at MHz rates, and assembling photon statistics conditioned on the exit times, we should be able to directly “watch” the evolution of the walk. This project will involve the design, fabrication and characterisation of a 3D quantum walk circuit using femtosecond laser direct write technology. The circuit will be excited by a femtosecond laser driven pulsed four-photon source and the correlations observed using silicon APD single photon detectors. The observed correlations will be interpreted in terms of the predicted photon statistics generated from fully quantum dynamical equations. The direct observation of quantum walk evolution would be a major result in this area. A more theoretical slant is also available for interested students.
Over the course of a 3-year PhD, we might investigate a number of different geometries, correlations involving larger numbers of photons and the active control of the circuits through thermal or other switching techniques.
Nonlinear (quantum) optics for fun and profit with hardly any light
It is somewhat paradoxical that quantum optics, which aims to manipulate light at the level of very few photons, is deeply intertwined (almost entangled!) with nonlinear optics, which of course exploits the effects of very high intensity light. Today, most single-photon or few-photon light sources for quantum optics and quantum information experiments depend on nonlinear frequency conversion. The nonlinear processes (for instance four wave mixing,) are quite familiar, except that some of the fields involved are quantum fluctuations which has profound consequences. While real world sources have improved dramatically, we are far from the ultimate goal of a desktop box that will emit a single identical photon at every press of a switch. Without such sources, real applications of quantum information and communication are held in limbo. Even once we have the perfect photon, the problem of moving it around the spectrum to enable long range quantum networking by wavelength-division-multiplexing is very much in its infancy. In this project, we aim to further develop theoretical understanding of the generation and frequency conversion of few photon non-classical states. We will choose from a number of possibilities, including improving photon sources by careful control of pump laser sources, or novel waveguide design; or exploring the robustness of quantum information protocols when used with imperfect states. Designing and modelling new sources requires the elegant apparatus of quantum field theory, and reveals very useful analogs between the classical and quantum regimes. We will uncover and explore such analogs, and use them to propose new experiments. There is a high probability that such experiments could then be carried out within the CUDOS Centre of Excellence.
A longer project would go on to explore a larger range of structures and protocols, make detailed comparisons with experimental work, and develop the basic formalism in new directions.
Exploring the complex physics of spins in solids
Diamond and specifically the nitrogen vacancy defect, is the only room temperature quantum bit technology known. By using the unique physics built in the this natural defect in diamond one can use a laser to initialize and read out the electronic spin quantum bit in the NV defect. Further one can use pulses of microwave radiation to control the NV diamond electronic qubit. However, this electronic qubit is very sensitive and suffers decoherence and typically dies away in tens/hundreds of microseconds. Researchers have shown that by use isotopically pure diamond (removing all C13 nuclear spins), one can extend the lifetime of the NV electron to milliseconds and further by using very complex laser/MW pulses the lifetime can even be extended to seconds! In this project we turn this around and ask how the electron spin – which is sensitively coupled to nearby (often unwanted), nuclear spins, can be used as a probe of the surrounding bath of nuclear spins. This project essentially involves combining traditional NMR/EPR pulse control with traditional engineering control methods to design protocols where one can learn more about the complicated physics of the surrounding nuclear spin bath. This theory project will require significant numerical modelling skills with the potential for parallel/supercomputer/GPU deployment. Supervisors: Prof Jason Twamley and A/Prof Gavin Brennen with potential collaboration with Prof F. Jelezko in the University of Ulm, Germany
This project is easily extended to harness the ability to use the electron spin to probe the surrounding nuclear spins. In particular a co-tutelle project with the University of Ulm, and Professor Fedor Jelezko – one of the leading experimentalist in the quantum engineering of diamond spins, is envisaged.
Simulation of quantum chemistry on quantum computers
As Feynman once said there is plenty of room at the bottom – in other words, there is virtually unlimited potential for designing new technology based on nanoscale systems. Such technologies could potentially solve some of the worldís most pressing problems. For example, they could enable more efficient renewable energy, or drugs to cure disease. Design of this technology requires the ability to predict the properties of chemical systems, which means simulation. For example, the Aspuru-Guzik team at Harvard recently used simulation of quantum chemistry to design a new type of battery that can be used to store energy from renewable energy sources. The difficulty in designing these quantum systems is that quantum mechanics is intrinsically difficult to simulate on regular “classical” computers. This motivated the idea of quantum computers, which would be able to simulate these systems far more quickly. Currently there is an international race on to build these quantum computers, and it is only a matter of time before they become available. It is not just a matter of running classical programs on quantum computers, though. To achieve the exponential speedups promised by quantum computers requires special quantum algorithms, which are radically different from classical algorithms. The current quantum algorithms for quantum chemistry are still quite demanding. In this project we will apply the latest advances in quantum algorithms to design techniques to more efficiently simulate quantum chemistry, so quantum computers could be used to design molecules. More specifically, we recently showed how to perform quantum compression of product formulae, where a long sequence of small operations is compressed exponentially using control qubits. In this project we will apply this to evaluate the integrals that appear in quantum chemistry.
This project only considers one technique for quantum simulation. It is easily extended to a PhD program by applying other techniques to simulation of quantum chemistry. There is also the more general problem of simulation of quantum fields, which could be used to provide testable predictions for theories of fundamental particles.
Anyons in slightly two-dimensional systems
Anyonic particles are some of the most exotic and enigmatic phases of matter imaginable. Capable of existing only in two dimensions, they exhibit complicated particle statistics where even simple operations such as pair exchange may drastically change the state of a system. Thanks to recent developments in numerical methods, it is now possible to study such systems using tensor network algorithms, and the quantum physics group at Macquarie has some of the most advanced software for the simulation of these systems in the world.
This project will specifically study densely packed lattices of Fibonacci anyons. Short-range interactions in the 1-D case (known as the Golden Chain) are well understood, but very little work has been done simulating anyons in 2-D. This project will study the behaviour of Fibonacci anyons when the Golden Chain is generalised to weakly two-dimensional systems such as ladders (with two, three, or more legs) and cigars.
Recommended skill set: Very comfortable with linear algebra and/or tensor calculus. Prior programming experience. You will be working with MATLAB: Prior experience with MATLAB is helpful, but not essential.
The holy grail of anyonic simulation is the study of fully two-dimensional systems. For anyons this is a multi-faceted problem, as all species of anyons exhibit a surprising sensitivity to the genus of the surface on which they exist. A PhD programme building on this MRes project would investigate existing tensor network techniques which could be adapted to the simulation of anyons in two dimensions, such as PEPS and spiral DMRG, develop the most promising such techniques, and would culminate in the numerical study of anyonic phase diagrams for truly two-dimensional systems.