Example Projects

Project Title & Abstract

Research Area


1D Models of Mass Ejection in Type I Photospheric Radius Expansion X-Ray bursts

In a close in binary star systems a sufficiently massive stars may explode as supernova and leave behind a neutron star, with a diameter of about the size of a city.  Later, as the system evolves, the smaller companion star may expand and transfer mass onto the neutron star, usually through an accretion disk.  When the material finally arrives at the surface of the neutron star, it first collects up in a thin and highly compressed layer, usually about the hight of a three-story house, before it ignites nuclear burning in a flash that incinerates the matter within seconds, burning it to heavy elements.  These events, recurring on time-scales of hours to days, are known as Type I X-ray bursts. Despite these bursts arise from such a thin layer, they are so energetic that we can see them all the way across the galaxy.

But whereas nuclear power and fusion on earth seems an incredibly powerful source of energy, releasing up to a few 0.1% of the rest mass of the matter, it hardly can match up with the incredible gravitational potential at the surface of a neutron star, amounting to some 20% of the rest mass!  So when such a nuclear-powered Type I burst goes off, it hardly has enough energy to blast off the surface of the neutron star - at least not in its entirety.  Some bursts, however, reach such high luminosity that they can blast off some of the material off the surface in the form of a "wind" - and may eject some of the newly synthesised material into the surrounding where it may be observable, due mostly to imprinting is signature on the light from the neutron star by absorbing some of the light, depending on its chemical composition.  We may directly learn about the freshly synthesised material of the burst - material that otherwise would disappear inside the neutron star for good without us ever being able to directly observe it.

The goal of this project is to model such high-luminosity bursts with wind and expansion of the photosphere, using a 1-dimensional hydrodynamic stellar evolution code, Kepler.  This may sound boring at first, but the code also follows an extended adaptive thermonuclear reaction network with some thousand nuclear species - as we do want to know what is being made and what is being ejected - and you can watch their evolution throughout the star as the simulation goes on.  You would run such models to explore different physical parameters of the system, such as accretion rate and composition of the accreted material, and follow each of system through several cycles of bursting, analysing the composition and amounts of material being ejected.  These would be the first such models with detailed nucleosynthesis.


H. Yu, N.N. Weinberg: "Super-Eddington Winds from Type I X-Ray Bursts", arXiv:1806.00164 (2018).

Astronomy & Astrophysics Professor Alexander Heger,
Associate Professor Duncan Galloway

3D Coherent X-ray Imaging for Breast Cancer Diagnosis:

Breast cancer is a major cause of cancer-related deaths around the world, with around eight Australians dying every day from this disease. Mammography (X-ray imaging of the breast) is the primary technique used in the diagnosis of breast cancer. However, it only produces low-contrast 2D images that are only accurate in detecting cancer between 67% and 80% of the time, with accuracy highly dependent on tissue density and homogeneity [1].  Furthermore, mammography delivers non-negligible radiation dose that can potentially cause cancer and it requires the breast to be compressed, which creates considerable discomfort for patients.

Using synchrotron radiation, we have recently shown that propagation-based phase-contrast tomography (PB-CT) can remove the need for breast  compression, whilst providing high-resolution, high-contrast 3D images of the tissue. Compared to conventional CT, PB-CT can deliver more than 20-fold improvement in the signal-to-noise ratio (SNR) at the same X-ray dose, or up to a 400-fold reduction in the X-ray dose without a loss in the imaging quality [2].

Using a newly constructed micro-focus phase contrast X-ray imaging system at Monash University, we aim to determine if this technology can be developed into a clinically compatible system that can greatly reduce the false positive and false negative rates of breast cancer diagnosis.


[1] ] von Euler-Chelpin, M., Lillholm, M., Vejborg, I. et al. Sensitivity of screening mammography by density and texture: a cohort study from a population-based screening program in Denmark. Breast Cancer Res 21, 111 (2019).

[2] Gureyev, T.E., S. C. Mayo, Y. I. Nesterets, S. Mohammadi, D. Lockie, R. H. Menk, F. Arfelli, K. M. Pavlov, M. J. Kitchen, F. Zanconati, C. Dullin, and G. Tromba, Investigation of the imaging quality of synchrotron-based phase-contrast mammographic tomography, Journal of Physics D: Applied Physics 47, 365401 (2014).

Imaging Physics Associate Professor Marcus Kitchen,
Dr Tim Gureyev (University of Melbourne)

3D imaging with in-line holography by exploiting implicit correlations in partially coherent waves

A Partial coherence of waves can be detected by the visibility of fringes in a double-slit experiment.  In a qualitative sense, a large degree of coherence, such as from mono-chromatic laser light sources, creates highly visible fringes.  On the contrary, a complete lack of coherence destroys all fringes and the visibility is accordingly zero.  Correlations between two locations at two different times can be used to quantify varying degrees of coherence in a stochastic wave field.

In-line holography typically analyses interference fringes imparted by specimens, which modulate incident wavefronts to create fine detail that develops as an exiting wave propagates in free space.  By studying this detail in recorded intensities, the wavefront deformation can be quantitatively measured to infer spatially varying phase shifts created by specimens of interest.  Since partial coherence degrades the contrast in these fringes, such effects are often considered to be detrimental to in-line holography.  In prior work, we have theoretically studied how this holographic fringe information can be generically described in partially coherent and aberrated fields [1].  We have recently found an interesting way to exploit this diminishment of fringe contrast, using the intrinsic properties of partially coherent sources.  In the context of phase contrast imaging, we realized that this variation of contrast surprisingly encodes useful depth information about the specimen, which is tomographic in nature [2].

We are looking for a talented student to study this depth-sensitive phase-contrast imaging approach further.  There are opportunities to explore this rich diffraction physics in light-optical experiments and discover new methods for probing specimen properties.  Alternatively, an interested student could further study the theoretical foundations and improve computer simulations to model these non-trivial effects.


[1] Mario A. Beltran, Marcus J. Kitchen, Timothy C. Petersen, and David M. Paganin, "Aberrations in shift-invariant linear optical imaging systems using partially coherent fields", Optics Communications, volume 355, 398-405 (2015).

[2] Mario A. Beltran, Timothy C. Petersen, Marcus J. Kitchen, and David M. Paganin,  "Extraction of depth moments by exploiting the partial coherence of radiation", Journal of Optics, volume 18, number 7 (2016).

Imaging Physics,
Condensed Matter Physics,
Theoretical & Computational Physics
Dr Timothy Petersen,
Dr Alexis Bishop,
Associate Professor Marcus Kitchen

3D Simulations of Low-mass Stars

Stars which have masses < 10 times that of the Sun are the most numerous in the Universe. Because of this they are very important contributors to the electromagnetic radiation of galaxies, and also the chemical evolution of the Universe. Given their importance, it is vital that we have reliable models of low-mass stars. However one-dimensional models are now showing their weaknesses, largely due to the revolution currently occurring in observations, through large surveys like GAIA, Kepler, GALAH. It is now quite urgent to update and improve the stellar models. One way forward is to make detailed 3D models of stars, which include hydrodynamics and nuclear burning, amongst other physics. Although it is still currently impossible to simulate the whole life of a star in 3D, short phases can now be simulated using the current generation of powerful Supercomputers. We can learn about the complex interplay of various physics from these 3D models, and then translate this to the 1D full-lifetime simulations, which will still be needed for many decades to come. In this project the student will work with a 3D stellar hydrodynamics code and analyse the flow and convective boundaries in a low-mass star. The student will run the code on the largest supercomputers in Australia (Magnus and/or Raijin).

Astronomy & Astrophysics Dr Simon Campbell

Anti-deuterons as the link between particle physics and astrophysics

From the large scale structure of the Universe, we know that the Universe has a very large component of Dark Matter, but have no ideas about the nature of it. One way to search for Dark Matter is to look for signatures of it annihilating at the centre of our galaxy. Such an annihilation might produce anti-deuterons which could subsequently be detected by space based instruments.

The exact production mechanism of anti-deuterons in the annihilation process lacks experimental measurements and data from the LHCb experiment based at the Large Hadron Collider might be able to provide this. The project will involve developing a new measurement method for the LHCb experiment where we will search for anti-deuterons both in the direct fragmentation process of proton-proton collisions as well as in the decay of the heavy anti-baryons that are produced. You will during the project learn how data analysis is done in particle physics and develop your programming skills in a large software project. The programming environment will be Python and C++. Prior experience with C++ programming is not required but you should be keen to gain experience.

Particle Physics Professor Ulrik Egede

Are the holes in the middle of protoplanetary discs made by planets?

What creates the large cavities seen in the centres of many protoplanetary discs --- photoevaporation of dust by the central star, or dynamical carving by massive planets or substellar companions? The aim of this project is to look for evidence of the latter. The idea will be to use models to predict how the gas flow in the central cavities of discs might reveal the presence of hidden companions.

Astronomy & Astrophysics Professor Daniel Price,
Dr Valentin Christiaens

Artificial Intelligence algorithms for real-time processing at the Large Hadron Collider

The LHCb experiment located at the Large Hadron Collider has been an incredibly successful. It has in recent years revealed hints for that the Standard Model of particle physics might not describe all phenomena. In particular there are signs that we do not have what is called lepton universality and that muons and electrons might behave differently. In order to understand this better, the LHCb experiment will go through a set of upgrades that will increase the available data by 2 orders of magnitude.

The data processing requirements for this is a challenge that does not yet have a solution. In the project you will investigate how Artificial Intelligence algorithms might be implemented in Field Programmable Gate Arrays (FPGAs) that form the boundary between software and hardware. In particular you will look at how the data coming from an upgraded calorimeter can be translated into energies and arrival times of electrons in real-time at a processing rate of 40 MHz. The programming environment will be Python.

Particle Physics Professor Ulrik Egede

Arrays on a regular lattice with optimal signal transmit and receive configurations

Recent work [1] used discrete projection theory to design families of numerical arrays where each array exhibits mathematically perfect auto-correlation, i.e. their off-peak periodic correlation is everywhere zero (or some constant). Furthermore, the cross-correlation between any pair of these family members is as low as theoretically possible. Such arrays find practical use in areas such as x-ray astronomy, digital communications and image watermarking. In [2, 3] it was shown that very large families of such arrays can be produced (in 2D, of order p 2 arrays, each of size pxp).

If we consider each active array location as a transmitter and/or receiver of signals, then these arrays can be adapted, using beam-steering methods, to produce powerful and very narrow directional beams useful for application in radar, ultrasound and microwave imaging. The transceivers can then be driven as Multiple Input Multiple Output (MIMO) arrays for intelligent sensing. The same array of N transceivers can also be reconfigured to act as a single transceiver: working in Single Input Single Output (SISO) mode.

This project considers the theoretical and practical construction of arrays with full MIMO capability by harnessing N independent ‘point-source’ transceivers configured in a pxp array to produce a single beam that has optimally narrow beamwidth and minimal side-lobes. Positive progress in this area was reported recently in [4]. Those arrays achieved side-lobes at least 3dB lower than previous efforts based on methods like simulated annealing and genetic algorithms. This project also considers the inverse problem, how to drive the same N transceivers so that the pxp array appears as a powerful single ‘point-source’ to maximise the SISO response.


[1] Families of multi-dimensional arrays with optimal correlations between all members, A. Tirkel, B. Cavy and I. Svalbe, Electronics Letters, 51(15) 1167-1168 (2105).

[2] Extended families of 2D arrays with near optimal auto and low cross-correlation, I. Svalbe and A. Tirkel, EURASIP Journal on Advances in Signal Processing (1) 18 (2107).

[3] Large families of ‘grey’ arrays with perfect auto-correlation and optimal cross-correlation, I. Svalbe, M. Ceko and A. Tirkel, to be presented at DCGI, Vienna, Austria, September, 2017.

[4] Radar retina or millimetre wave eye? A. Tirkel and I. Svalbe, invited paper, IEEE Conference UKRCON 2017, Kiev, Ukraine, June, 2017.

Imaging Physics Dr Imants Svalbe,
Dr Andrew Kingston (Research School of Physics & Engineering ANU)

Asteroseismology of red giants

Stars are big balls of gas and they are excellent cavities for sound waves. The study of these waves in the Sun is known as selioseismology, in analogy with the seismic waves found on Earth. Recently, the Kepler satellite has been observing thousands of red-giants. This has allowed us to determine the seismic oscillations of these stars - a field of study known as "asteroseismology". The theory of these oscillations is well known but it is only now that we are getting real data for real stars. Kepler data is very accurate and it is allowing us to probe the interior of red-giants for the first time. The details of mixing during the phase of helium burning in the core are particularly poorly known. Recent work using Kepler data might allow us the possibility to determine the extent of the mixed region from observations! This project would involve gaining a thorough understanding of seismology and also the details of core helium burning in low mass stars. Then you will modify the stellar evolution code to calculate the things that observers can measure. Can we then use the existing data to make some constraints on the mixing seen in the models?


Christensen-Dalsgaard, J 2014, 'Stellar Oscillations', online lecture notes at: users-phys.au.dk/jcd/oscilnotes/print-chap-full.pdf

Bedding, TR et al. 2011, 'Gravity modes as a way to distinguish between hydrogen- and helium-burning red giant stars' Nature, vol. 471, pp. 608-611.

Van Grootel, V et al. 2010, 'Early asteroseismic results from Kepler: structural and core parameters of the hot B subdwarf KPD 1943+4058 as inferred from g-mode oscillations' Astrophysical Journal Letters, vol. 718, no. 2, pp. L97-L101.

Astronomy & Astrophysics Professor John Lattanzio,
Dr Simon Campbell

Atom based potentials for atomtronics

Atomtronics is an emerging research area that seeks to develop devices that will exploit the unique properties of ultracold atoms to deliver benefits over conventional technologies. Potentials based on optical fields are currently used to manipulate and pattern ultracold atoms, which limits feature sizes to the wavelength of light. This project would investigate potentials for ultracold atoms based on atom-atom interactions. In this manner, we can realize corrals, interfaces, barriers and junctions for ultracold atoms that can be more than 10 times finer than what can be currently achieved. Of particular interest is the realization of an atom-based Josephson tunnel junction for use in an atomic SQUID device.

Quantum Gases Professor Kris Helmerson

Atomic-scale structural and electronic studies on light-harvesting metal-halide perovskites

Hybrid organic-inorganic perovskites are an emerging class of photovoltaic materials with the potential to outperform silicon [1] . Solar cells made of metal-halide perovskite offer material costs below $2/m 2 and certified efficiencies beyond 20%. However, the underlying physical mechanisms allowing for strong light absorption and efficient electron-hole separation in metal-halide perovskites are not fully understood. In particular, very few studies have been performed on the atomic-scale properties of these materials. This project aims to combine expertise in synthesis, crystal growth, solar cell assembly and morphology control, with scanning-probe based surface analysis, in order to deepen our understanding of the structural and electronic properties of perovskite materials at the atomic scale. Metal-halide perovskite crystals will be synthesised by collaborating groups. Atomic-scale structural, electronic and optoelectronic properties of such materials will be studied by low-temperature scanning tunnelling microscopy (STM) and spectroscopy (STS), non-contact atomic force microscopy (ncAFM), as well as synchrotron-based x-ray studies (x-ray photoelectron spectroscopy (XPS), near-edge x-ray absorption fine structure (NEXAFS)). Perovskite crystals will be cleaved in ultrahigh vacuum (UHV) and characterised in situ. These experiments will allow to correlate atomic-scale electronic structure with the materials’ light-harvesting functionality.


[1] Samuel D. Stranks and Henry J. Snaith, "Metal-halide perovskites for photovoltaic and light-emitting devices", Nature Nanotechnology, volume 10, 391-402 (2015).

Condensed Matter Physics Dr Agustin Schiffrin

Atomically thin materials coupled to light

The past couple of decades has seen a revolution in materials technology, the emergence of atomically thin materials. This was initiated by the discovery of graphene (2010 Nobel prize), but the field now comprises a range of different materials in the ultimate single-atom-thin limit. This project will focus on a particular class, the so-called transition metal dichalcogenides (TMDs), that possess a range of properties that make them of great interest for applications in electronics and optoelectronics. First of all, the typical energy scales in these systems are well above room temperature, meaning that one can potentially observe non-trivial quantum effects without resorting to cryogenic environments. Furthermore, these materials interact very strongly with light, which enables a host of applications from quantum information processing to atomically thin LEDs. Our group has a number of different projects in this area, related to the prospect of generating strong interactions between photons by strongly coupling light to matter, the possibility of generating superfluids of light-matter quasiparticles, and the interplay of light-matter coupling and electronic doping. Part of this research is within the scope of the ARC Centre of Excellence in Future Low-Energy Electronics Technologies.

Condensed Matter Physics,
Theoretical & Computational Physics
Dr Jesper Levinsen,
Associate Professor Meera Parish

Better bases?

Both as a consequence of its inheritance from X-ray diffraction theory, and because it arises naturally in the process of far-field diffraction, electron microscopy frequently works in a Fourier basis. However, these are not the eigenstates of electron waves inside materials (which in crystals are Bloch states), and build in assumptions about periodicity that do not apply well to non-crystalline materials. Drawing heavily on mathematical theory and numerical computation, this project seeks to recast electron scattering in different bases, to explore whether they offer new insights or efficiencies [1].


[1] S.B. Tochilin & M.J. Whelan, Combined basis algorithm for HREM wave field calculations, Ultramicroscopy 50 (1993) 313

Imaging Physics,
Theoretical & Computational Physics
Dr Scott Findlay

Blind ghost imaging through scattering media

Ghost imaging is a technique that uses structured light and the correlations between the input light patterns and the transmitted light to reveal details of objects hidden behind highly scattering media.

Recent research [1] has revealed that light forward-scattered from a scattering medium is highly correlated with the transmitted light. This allows the usual transmitted-light detector used in ghost imaging to be relocated to the front of the scattering media. Consequently, images of objects hidden beneath a scatterer can be visualised using only the scattered light, and measuring the correlations with a series of input beam shapes. This allows structures at depth in tissue to be visualized without requiring a detector behind the object [2].

This experimental project is explore “blind” ghost imaging in the highly scattering regime and determine the range of validity and the implications for deep tissue imaging in humans.


Ilya Starshynov et al.  Phys. Rev. X 8, 021041 (2018)

Alba M. Paniagua-Diaz et al. Optica 6, 460-464 (2019)

Imaging Physics Dr Alexis Bishop

Bolometric corrections for quasars

While quasars emit across the whole spectrum of light, practically astronomers are usually limited to observing them in relatively narrow spectral windows. For example, for high redshift quasars we may be limited to the restframe ultraviolet and optical. The bolometric luminosity, measured across the entire spectral energy distribution, can be critical for constraining the accretion rate and Eddington ratio for the relevant quasar. In this work we propose to use new quasar spectral energy distributions to update corrections for quasar bolometric luminosity. These spectral energy distributions offer significantly advantages over previous work, including new X-ray and far-infrared data.


Brown et al. (2019), MNRAS - in press

Runnoe et al. (2012), MNRAS, 422, 478

Moustakas and Kennicutt., 2006, ApJS, 164, 81

Astronomy & Astrophysics Associate Professor Michael Brown

Building the next generation of protoplanetary disc models

The new generation of astronomical instruments, the Atacama Large Millimetre Array (ALMA) and adaptive optics systems, offer revolutionary views of forming planetary systems around young stars. They reveal a multitude of unexpected structures in protoplanetary discs: rings and gaps, azimuthal asymetries, spirals. The detailed interpretation of theses new observations requires advanced disc models combining  hydrodynamics, radiative transfer and chemistry. This remains beyond current modelling capabilities.

In this project, we will explore how we can use advanced machine learning methods to signficantly speed up the calculations by predicting the disc chemical and thermal evolution from a database of existing models. Peliminary tests have been performed and look very promising. The goal of this project will be to quantify systematicaly how well machine learning perform and to use the newly developed algorithm to study the evolution of 3D disc models, where dust concentrates in "traps", where we believe the core of planets could form.

Astronomy & Astrophysics Dr Cristophe Pinte

Building the standard model of particle cosmology

The standard model of elementary particles is one of the most successful theories in science describing all observable physical processes in the solar system, some to ten significant digits.  Similarly, the LambdaCDM model of cosmology correctly describes the key aspects of our observable universe with a high precision [1].

Excitingly, these two models have a common origin: the standard model of particle cosmology.  This mode, however, is not fully crystallised yet. Its main pillars, the particle explanation of inflation, the origin of visible and dark matter and the nature of dark energy are subject of intense research [1,2].

The aim of this project is to analyse various theories beyond the standard particle model.  These theories have specific predictions for inflation, the matter content of the universe [3], and its vacuum configuration.  These predictions will be used, in conjunction with many of their other consequences, to calculate statistical measures to quantify their plausibility using the novel CosmoBit framework [1,4].


[1] GAMBIT Cosmology Workgroup CosmoBit: A GAMBIT module for computing cosmological observables and likelihoods

[2] GAMBIT Cosmology Workgroup Strengthening the bound on the mass of the lightest neutrino with terrestrial and cosmological experiments

[3] Global analyses of Higgs portal singlet dark matter models using GAMBIT Eur.Phys.J.C 79 (2019) 1, 38

[4] GAMBIT Collaboration GAMBIT: The Global and Modular Beyond-the-Standard-Model Inference Tool Eur.Phys.J.C 77 (2017) 11, 784, Eur.Phys.J.C 78 (2018) 2, 98 (addendum)

Particle Physics Professor Csaba Balazs

Can we form planets quickly?

There is an old idea in planet formation called the Goldreich-Ward mechanism, where planets are made quickly by direct gravitational fragmentation of a thin dust layer. The aim of this project is to try to simulate this mechanism for the first time in 3D, to see if it might actually work in practice.

Astronomy & Astrophysics Professor Daniel Price,
Dr Christophe Pinte

Complexity and frustration

As states of matter, single crystals and ideal gases represent extremes of order and randomness, yet both are relatively simple to model and understand; they have a structural complexity of zero. Most materials exist in an intermediate range, lacking perfect translational symmetry, but possessing both random and ordered elements, correlation lengths and hierarchies. Complexity and information content in material structures has been suggested as a means to move “beyond crystals” [1] and formulate a means to categorizing all materials within a single framework. A key challenge is to devise methods to measure complexity from data and connect this to material properties, which may depend on the history of the sample in question.
Glasses are materials that solidify in a disordered structure, and are paradigmatic examples of structurally complex matter. The viscosity of the melt from which they form increases by many orders of magnitude over a very small temperature range as the material goes through the glass transition temperature [2]. It appears as though most materials will form a glass if quenched quickly enough to suppress crystallisation, but it is a puzzle why some materials like silica, are much better at glass forming than others.
Recent theoretical work has suggested that materials with a large number of antagonistic low-energy local structures in the melt have higher glass-forming ability [3]. As the energy is lowered, efficient packing of these local units is frustrated, and the liquid phase is stabilised. Eventually the atoms don’t have enough energy to move and structural disorder is frozen in.
This project will develop new measures of structural complexity from electron nano- diffraction patterns of glasses [4,5]. These measures will be used to test whether signatures of the variability of local structures from the parent melt persist in the glass as structural complexity and provide verification of the structural origin of good glass-forming ability. The ability to design better glass-forming systems will unlock new technological and manufacturing opportunities in the realm of building, glassware, smart devices, optoelectronics and communications.
This project would suit a student who is interested in condensed matter physics, complexity theory and machine learning, and may include collaboration with Dr Felix Pollock. It can be tailored to suit students with both experimental and theoretical interests.


[1] ] J. H. E. Cartwright and A.L. Mackay, Phil. Trans. R. Soc. A, 370, 2807–2822 (2012).

[2] C. A. Angell, K. L. Ngai, G. B. McKenna, P. F. McMillan, S. W. Martin, J. Appl. Phys., 88, 3113-3157 (2000).

[3] P. Ronceray and P. Harrowell, J Stat. Mech. Theor. Expt., 084002, (2016)

[4] A. C. Y. Liu, M. J. Neish, G. Stokol, G. A. Buckley, L. A. Smillie, M. D. de Jonge, R. T. Ott, M. J. Kramer, and L. Bourgeois, Phys. Rev. Lett. 110, 205505 (2013)

[5] A. C. Y. Liu, R. F. Tabor, L. Bourgeois, M. D. de Jonge, S. T. Mudie, and T. C. Petersen, Phys. Rev. Lett., 116, 205501 (2016)

Imaging Physics,
Condensed Matter Physics,
Theoretical & Computational Physics
Dr Amelia Liu,
Dr Kavan Modi,
Dr Felix Pollock

Computational star and planet formation

How are stars born? How are solar systems formed in the discs around newborn stars? We are getting plenty of new observations from telescopes like the Atacama Large Millimetre/Submillimetre Array (ALMA) and the James Webb Space Telescope (JWST), but to understand what we’re seeing, we need to model it. Our group develops advanced numerical methods for modelling star and planet formation on modern supercomputers. A typical honours project might involve improving our modelling of dust, gas, radiation, magnetic fields or gravity to try to better explain the observations, or to apply our existing 3D code to some open problems. Feel free to swing by and have a chat to discuss possible directions.

Astronomy & Astrophysics Professor Daniel Price

Confronting Theory and Experiment at the Large Hadron Collider

High-energy collisions between subatomic particles, such as those that occur at the LHC, are often too complicated to calculate by hand. At Monash, we use random numbers and a property called factorisation to simulate the quantum probability distributions of such reactions. Such computer models, called “Monte Carlo event generators", are able to provide simulated events in as much detail as the real collider events, against which therefore very detailed comparisons can be made. This is essentially how theory and experiment are compared in practice, in modern high-energy physics. However, the necessity to make approximations implies that no model is absolutely perfect. In this project, we will consider state-of-the-art physics models and subject them to trial by fire in the form of constraints imposed by very recent measurements performed at the Large Hadron Collider (LHC). The project is well suited for students with an interest in collider physics phenomenology, computing (the simulations and analyses are written in C++), and will also involve aspects of LHC data analysis.

Particle Physics Associate Professor Peter Skands

Constraining nuclear reactions with thermonuclear bursts

Many of the thousands of thermonuclear reactions taking place in X-ray bursts from neutron stars have rates that cannot be measured precisely in terrestrial laboratories. In recent years, modelling efforts have begun to identify which specific reactions have the most influence on the observational properties of the bursts. At the same time, large samples of high-quality observational data on bursts exist, but comprehensive comparisons of the model predictions with observations have not taken place. This project would involve comparisons of numerical burning model predictions with observations to attempt to constrain nuclear reaction rates. The student will take advantage of the sample of several 1000s of bursts as part of the Multi INstrument Burst ARchive (MINBAR), as well as existing collections of model runs from collaborators, and local modelling capabilities. Part of the project could involve development of online web-based tools to improve the usability of existing data. Additional work could include exploring varying stellar parameters including gravity (mass/radius) and heating rate.


Cyburt, RH et al. 2010, 'The jina reaclib database: Its recent updates and impact on type-I X-ray bursts', Astrophysical Journal, Supplement Series, vol. 189, no. 1, pp 240-252.

Astronomy & Astrophysics Associate Professor Duncan Galloway,
Professor Alexander Heger

Constraining supernovae properties by their nucleosynthesis

Most heavy elements from oxygen to iron are dominantly made by the deaths of massive stars as supernovae. Whereas fully understanding such core collapse supernovae requires multi-dimensional simulations including complicated and expensive radiation transport physics, there is some progress in developing simpler approximation formulae for these supernovae given the structure of the star at the time of its death. Depending on the explosion properties, supernovae synthesise and eject elements in different proportions, which can be used as a diagnostic of the explosion model. For this project you will use an analytic model for supernova explosions and their energies to simulate the nucleosynthesis of these stars. The result is to be compared to the abundance patterns - elemental and isotopic - that we find in the in the universe today, in the sun, and on earth. The goal of the project is to constrain the properties of the analytic supernovae model in its ability to reproduce the observed data.


Hans-Thomas, J 2012, 'Explosion mechanisms of core-collapse supernovae', Annual Review of Nuclear and Particle Science, vol. 62, issue 1, pp. 407-451.

Pecha, O & Thompson, TA 2013, 'The Landscape of the Neutrino Mechanism of Core-Collapse Supernovae: Neutron Star and Black Hole Mass Functions, Explosion Energies and Nickel Yields', arXiv.org > astro-ph > arXiv:1409.0540

Rauscher, T, Heger, A, Hoffman, RD & Woosley, SE 2002, 'Nucleosynthesis in Massive Stars with Improved Nuclear and Stellar Physics', The Astrophysical Journal, Volume 576, Issue 1, pp. 323-348.

Woosley, SE, Heger, A & Weaver, TA 2002, 'The evolution and explosion of massive stars', Reviews of Modern Physics, vol. 74, Issue 4, pp. 1015-1071.

Astronomy & Astrophysics Professor Alexander Heger

Dark-field X-ray Imaging using MIST

Recent advances in X-ray imaging can provide much more information about objects than traditional radiography. Using coherent X-ray optics, these techniques can quantify how an object alters the phase of the X-ray wavefield and extract a dark-field signal, which arises from small-angle scattering from unresolvable objects within the object. These new sources of information have proven highly useful for disease detection and materials characterisation [1].

A new technique, called Multimodal Intrinsic Speckle Tracking (MIST) [2], provides a simple and fast way to recover multimodal information about the sample’s absorption, phase and dark-field (coherent scattering) properties. It works by illuminating a random phase screen with coherent X-rays to create a speckled intensity pattern. This pattern is warped in the presence of an object. Decoding this warping reveals how the sample interacted with the coherent X-ray photons. MIST is based on combining a Fokker-Planck description of paraxial X-ray optics, with an optical-flow formalism for X-ray speckle-tracking. Only two images need to be taken in the presence of the sample in order to recover both the phase and dark-field properties of the sample. Like the optical-flow X-ray method which it generalizes, the method implicitly rather than explicitly tracks speckles. Application to X-ray synchrotron data shows the method to be efficient, rapid and stable [2].

Using a newly constructed phase contrast X-ray imaging system at Monash University, we aim to develop MIST for use with compact, micro-focus X-ray systems for clinical and industrial application for disease diagnosis and materials characterisation.


[1] M. J. Kitchen, G. A. Buckley, L. T. Kerr, K. L. Lee, K. Uesugi, N. Yagi, and S. B. Hooper, “Emphysema quantified: mapping regional airway dimensions using 2D phase contrast X-ray imaging,” Biomedical Optics Express 11(8), p4176, 2020.

[2] K. M. Pavlov, D. M. Paganin, H. Li, S. Berujon, H. Rougé-Labriet, E. Brun, “X-ray Multimodal Intrinsic-Speckle-Tracking”, arXiv:1911.06814, 2019.

Imaging Physics Associate Professor Marcus Kitchen,
Dr Konstantin Pavlov (University of Canterbury)

Deeper bluer galaxies

There is often a discontinuity between redshift z=0.5 and redshift z=0.05 studies of the galaxy evolution, with sudden jumps in the number of elliptical and red galaxies. This may be a consequence of biases in local studies of well-resolved galaxies, as the morphologies and colours of galaxies are a function of the depth and angular resolution of the images used to measure galaxy properties. For example, in shallow images the red central bulge is observed while faint extended blue arms are missed. Using galaxies selected from local redshift surveys, SDSS images and DES images, we will measure the photometry and morphologies of relatively nearby galaxies, and quantify the nature of this bias for local galaxy samples.


[1] Baldry et al., 2017, MNRAS, 474, 3875

[2] Brown et al., 2007, ApJ, 654, 858

[3] Graham et al., 2005, AJ, 130, 1535

[4] Robotham et al., 2017, 466, 1531.

Astronomy & Astrophysics Associate Professor Michael Brown

Detecting gravitational waves from supermassive black holes

Gravitational-wave astronomy is now a reality.  Advanced LIGO has detected gravitational waves from merging black holes, each with mass tens of times more than the Sun.  A complementary experiment using rapidly rotating neutron stars (pulsars) aims to detect gravitational waves from black holes with masses more than a billion times that of our Sun.  In this project, we will either work with the pulsar data to make such a detection possible, or develop the astrophysical models to understand the expected gravitational-wave signal.

Astronomy & Astrophysics Dr Paul Lasky,
Dr Xingjiang Zhu

Detecting the signatures of forming planets

Planet form in discs of gas and dust rotating around young stars. While the recent Kepler survey has shown that planet formation is ubiquitous, with more than one planet per star on average, forming planets within the disc have remained elusive so far, with only a few candidates.

In this project, we will explore how we can calculate the kinematical signatures left by a planet in a disc as well as the signature of gas accretion onto the forming planet and compare it to current observations, as well as make predictions for the next generation of instruments.

Astronomy & Astrophysics Dr Cristophe Pinte

Developing high-performance 2D transistors

Atomically-thin transistors made by 2D semiconducting materials possess attractive electronic properties and have been seen as building blocks for next-generation semiconductor chips. This project aims to study the transport properties of 2D field-effect transistors, including carrier mobility and contact resistance. In particular, we will focus on optimising the metal-semiconductor junction. In other words, we will develop high-performance 2D transistors by achieving Ohmic contacts to metals, paving ways to use these materials in new low-energy dissipation devices. This project will involve fabricating atomically-thin 2D semiconductors with the state-of-the-art equipment in a cleanroom, performing the electrical measurements, and analysing and interpreting the data.

Condensed Matter Physics Professor Michael Fuhrer,
Yi-Hsun Chen

Distortion elimination in acoustic transducers

Audio reproduction transducers (speakers) have been essentially unchanged in design and performance for many decades. The performance, in terms of linearity of reproduction from a driving signal is surprisingly poor, particularly at low frequencies (<1 kHz), with significant amplitude (~10 %) and phase nonlinearity being present even in the best drivers. Distortion of the output waveform arises from departures from the idealized model (a driven damped harmonic oscillator), which generates additional harmonics, and significantly, intermodulation distortion (typically several percent for frequencies < 200 Hz), when a complex drive signal is present. Correction of the nonlinearities is possible by modifying the driving waveform to compensate for the nonlinear motion of the driver.

This experimental and computational project is to develop a practical system based on neural networks to compensate for the nonlinearities in the driver behaviour, and hence ensure the reproduced sound intensity is directly proportional to the driving signal.

Theoretical & Computational Physics Dr Alexis Bishop

Do stars swallow their planets?

How special is our Solar System? For years the Sun was thought to be a typical solar type star, but strikingly a few years ago the Sun was found to be chemically peculiar, with a deficit of rocky-forming elements. More intriguingly, this anomaly could be related to the less-common planet architecture (inner rocky planets, outer gaseous planets, orbits that never cross) of our System.

In fact, the apparent regularity of the motion of the planets in our Solar System suggests that they formed on orbits similar to their current ones and that nothing dramatic happened to them during their lifetime. On the other hand, most of the exoplanetary systems discovered so far have suffered from severe planet migrations and, eventually, planet engulfment events. When rocky material enters into the star, it is rapidly dissolved in the stellar envelope. Such external pollution will produce a stellar chemical pattern that mirrors the composition observed in rocky objects,  with the most refractory elements (e.g., Fe, Ti, Al, Sc) being more abundant than in the Sun, where this pollution seems to have not occurred.

The main goal of this project is to test the chemical homogeneity of stellar systems, such as open clusters and binary systems, to a level that was unthinkable only few years ago, taking advantage of a special technique that will allow us to achieve very high-precision abundance determinations. Members of these systems were formed from the same material, so they should have started as chemically identical. Any difference in the rocky-forming elements among the members of these stellar associations is likely related to the architecture of planetary systems or to planetary engulfment events.

This project will test the intriguing possibility that the chemical composition of stars can carry information relevant to the architecture and evolution of planetary systems. Unveiling chemical signatures of planet engulfment events will allow us to asses how rare our Solar System is and will yield a list of stars with the best chances of hosting stable planetary systems like ours.

Find more details on my webpage: https://research.monash.edu/en/persons/lorenzo-spina


[1] Melendez et al. 2009, "The Peculiar Solar Composition and Its Possible Relation to Planet Formation", ApJ, 704, 66

[2] Melendez & Ramirez 2017, "Planet signatures in the chemical composition of Sun-like stars", The 19th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, arXiv:1611.04064

[3] Spina et al. 2018, “Chemical inhomogeneities in the Pleiades: signatures of rocky-forming material in stellar atmospheres”, eprint arXiv:1807.00941

Astronomy & Astrophysics Dr Lorenzo Spina

Dynamics of single molecules in a nanotube

The cell is a crowded environment where complex chemical reactions take place, typically involving only a few numbers of molecules. While a number of these reactions have been studied in bulk assays or even at the single molecule level, the role of crowded environment or confinement has typically not been investigated. The goal of this project is to study the dynamics of single molecules and molecular complexes under the influence of confinement. An apparatus will be developed to create nanotube extensions from vesicle by pulling on self-assembled vesicle membranes. The nanotube-vesicle structures can be made stable in the case where the membranes are formed by cross-linkable polymers. Single molecules, such as genomic length DNA, will be driven to enter the nanotube and the dynamics of the molecule will be studied by fluorescence microscopy.

Imaging Physics Professor Kris Helmerson

Electrodynamics of Weyl semimetals

Weyl semimetals are new topological solids with protected massless Dirac electronic states in their bulk and exotic Fermi arc surface states. The electrodynamics of these materials have additional "axion" terms that can manifest as in transport as in optical phenomena and have attracted recently a lot of attention.

The project is devoted to an analysis of a distribution of electric and magnetic fields induced by a point charge near Weyl semimetal surface that can be addressed within the method of image charges.  [1].


[1] X.L. Qi, R. Li, J. Zang, S.-C. Zhang - Science 323, 1184 (2009)

Quantum Gases,
Condensed Matter Physics,
Theoretical & Computational Physics
Dr Dmitry Efimkin

Electrons and photons as emergent phenomena

This project addresses the question: are electrons and photons fundamental particles or emergent phenomena? In ref. [1] it was demonstrated that one could construct a U(1) gauge theory (of light) based on a local bosonic model. Fundamental to this approach is the notion of a new kind of order, called topological order, in which particles arise from excitations of a string-net condensed phase. However, these strings are fundamentally different from the superstrings in high-energy particle physics. A simple lattice bosonic model will be used to explore the emergence of U(1) gauge theory in the low energy regime. Possible extensions will include an exploration of how spin-2 gravitons might arise from a lattice bosonic model.


[1] M. Levin and X-G Wen, "Colloquium: Photons and electrons as emergent phenomena", Reviews of Modern Physics, Volume 77, Issue 3 (2005).

Particle Physics,
Theoretical & Computational Physics
Professor Michael Morgan

Ensemble gravitational wave detections: more than the sum of the parts

Gravitational-wave astronomy is now a reality. In February 2016, LIGO announced the first direct detection of gravitational waves from the collision of two black holes, each with mass approximately 30 times that of the Sun. From the first observing run of Advanced LIGO, two bona fide detections were made of binary black hole mergers, and one further candidate detection. These detections allow us to predict the event rate of future detections given the planned improvement in instrument sensitivity. The future is very bright with tens to hundreds of detections expected in the next two or three years. In this project, we will explore physics that can be learned from an ensemble of gravitational wave detections that cannot be learned from any given detection. For example, we recently published a paper [1] showing that gravitational-wave memory—a permanent deformation of spacetime following the emission of gravitational waves—can be detected confidently once approximately 30 loud binary black hole mergers have been detected with Advanced LIGO. Potential projects involve looking for deviations from General Relativity in ultra-strong gravitational fields or trying to understand how these stellar-mass black holes formed in the first place.


[1] Paul D. Lasky, Eric Thrane, Yuri Levin, Jonathan.Blackman, and Yanbei Chen, "Detecting Gravitational-Wave Memory with LIGO: Implications of GW150914", Physical Review Letters, Volume 117, 061102 (2016).

Astronomy & Astrophysics Dr Eric Thrane,
Dr Paul Lasky

Entangling an atom and a brain wave

Is there a quantum state which is optimal for detecting a brain wave? Neurons communicate by emitting pulses which are a very predictable shape. Neuroscientists believe that thinking is encoded in the timing of these pulses, but not in changes in their amplitude or shape. Rather than detecting these pulses with invasive voltage probes, we aim to measure the magnetic fields generated by the tiny neurocurrents that flow between neurons. In this project you'll explore whether there is an optimal quantum state for a spin-1 atom to detect the magnetic field of a single neural impulse. The project will have theoretical, simulation and experimental components.

Quantum Gases Dr Lincoln Turner

Epitaxial growth of a 2D TMD

Topological materials, like topological insulators and topological Weyl semimetals, are a new classes of matter with unusual electronic properties: Weyl semimetals have Weyl points in their bandstructures, around which electrons behave as massless chiral particles (similar to neutrinos). Topological insulators are insulators in the bulk but have highly conducting massless helical electrons on their surfaces or edges.

One way to synthesise these new topological materials is by depositing them on suitable substrates, literally one atomic layer at a time, via molecular beam epitaxy (MBE). This technique, available in our labs, allows for the growth of *virtually* perfect, large-area epitaxial crystals, ready to unravel all of their unique properties.

In this project you will focus on the Weyl semimetal WTe2, which is expected to be a topological insulator when thinned to one atomic layer. You will uncover the interplay between atomic species to optimize the growth recipe, and this will involve preparing substrates and performing growths. During growth you will utilize in-situ diffraction techniques to confirm crystallinity and sample quality. After successfully growing these materials low-temperature scanning tunneling microscopy (STM) will be employed to study the electronic properties, complemented (time permitting) by photoemission measurements to be carried out both at Monash University and at the Australian Synchrotron.

If you have any questions, please contact Dr Iolanda Di Bernardo at iolanda.dibernardo@monash.edu, Dr Mark Edmonds at mark.edmonds@monash.edu or Prof. Michael Fuhrer at michael.fuhrer@monash.edu.

Condensed Matter Physics Dr Iolanda Di Bernardo,
Dr Mark Edmonds,
Professor Michael Fuhrer

Excitonic superfluidity in electron-hole bilayers

Superconductivity and superfluidity are macroscopic quantum phenomena that are observed at low temperatures. Bringing them to room temperatures is the Holy Grail in physics. One prospective system is a double layered semiconductor structure with spatially separated electrons and holes (holes are empty electronic states that can be treated as particles with positive charges). Attractive Coulomb interactions can bind them to become excitons (a hydrogen-like molecule formed by an electron and a hole) and drive them to become an excitonic superfluid. After years of attempts, fully equilibrium excitonic superfluids have been recently discovered in novel bilayer structures formed by exotic monolayer materials. Uncovering peculiar properties of excitonic superfluids in these novel systems is the aim of this research topic.


G. William Burg, Nitin Prasad, Kyounghwan Kim, Takashi Taniguchi, Kenji Watanabe, Allan H. MacDonald, Leonard F. Register, and Emanuel Tutuc. Phys. Rev. Lett. 120, 177702 (2018).

Isabelle Dumé, Low Temperature Physics - Research Update, Physics World (2019)

Quantum Gases,
Condensed Matter Physics,
Theoretical & Computational Physics
Dr Dmitry Efimkin

Exoplanets: How do they form?

Our group recently made several first detections of newborn exoplanets still embedded in their protoplanetary discs. In this project we will combine computer simulations of planet-disc interaction with radiative transfer to understand the observations and help to constrain the planet formation mechanism.

Astronomy & Astrophysics Professor Daniel Price,
Dr Christophe Pinte

Exoplanets: Resonance capture during planet formation

Planets are formed in protoplanetary disks, the latter being composed of a mixture of dust and gas. The process involves accumlation of dust into planetesimals, which in turn collide to form planet "cores" which, if massive enough, go on to accrete a massive gas envelope to become gas giants. These nascent planets in turn raise a tide in the disk from which they form. Such a tide will be in the form of a spiral density wave, and since the associated density enhancement is non-axisymmetric, it will exert a torque on the planet and hence exchange angular momentum with its orbit.

The latter process is called planet MGEation. It causes the planet to move towards or away from the star, depending on the "balance of torques" (there will be perturbations to the planet's orbit coming from the interior and exterior portions of the disk), and in some cases such torques will balance and the planet will remain stationary (at least on some timescale which is probably short compared to the lifetime of the disk).

In the case that there is more than one planet (which is surely the general case), the rates of change of their semimajor axes will in general be different. As such, the ratio of the orbital periods will either increase ("divergent MGEation") or decrease ("convergent MGEation"). In the latter case, the planets would collide if it weren't for a beautiful process called resonance capture which prevents this from occurring.

This project will study the process of resonance capture with a view to understanding the period-ratio distribution of exoplanetary systems, especially those discovered by the Kepler space telescope. This is a prominent unsolved problem in exoplanet science, and its solution will give us deep insight into the process of planet formation.

Astronomy & Astrophysics Dr Rosemary Mardling

Exoplanets: Transit timing variations (TTVs) in the Kepler planet candidates

Before the Kepler space telescope was launched, the vast majority of exoplanet detections were made using the Radial Velocity method. This spectrocopic method measures the minute Doppler shifts in all available stellar spectral lines, and allows one to measure the minimum mass of the planet responsible for the motion of the star as long as one has a good estimate for the latter. In contrast, the transit method of detection is a photometric method which measures the deficit of photons when a planet passes across the face of the star being observed. This allows one to estimate the radius of the planet as long as one has a good estimate for the radius of the star. Thus the RV and transit methods are complementary, and if one detects a system both ways, one can estimate the mean density of the transiting planet. In turn, this allows one to say something about the likely internal structure of the planet, an amazing fact which has attracted geoscientists to join the burgeoning field of exoplanets.

Kepler has used the transit method to detect thousands of planet candidates, but unfortunately the Kepler field is very distant and so most of their host stars are too faint to follow up with RV measurements. [Kepler is not a "pointing telescope" (its field of view is fixed) and so a field towards the crowded Galactic centre was chosen to optimise the number of target stars.] Without RV follow-up, it is generally not possible to measure the planet's mass, and since there are "non-planet" ways to produce a planet-like signal (for example, if the star is orbited by a distant close binary), one cannot confirm the planetary nature of the detection. Fortunately, there are quite a few bright stars with planet candidates in the Kepler field which are amendable to RV analysis, and since their planet transit, their actual masses and hence their densities have been determined. However, the vast majority of candidates are not in this category.

This would have been a disaster for the Kepler mission had it not been realised that the presence of a second planet could reveal itself through the perturbations it causes to the timing of the observed transit, in particular, to the time at which the planet crosses the midline of the star even when the second planet is not detectable (by transiting itself or by RVs). By forming a time series of these transit timing variations, one is then able to use it to deduce (in favourable cases) many of the orbital parameters of the whole system including the planet masses.

TTVs have been a boon to the Kepler mission, but the vast majority of planets candidates still remain just that - candidates. This project will use new mathematical methods to reveal the planetary nature of some of these systems, thereby adding to our knowledge of the rich variety of planets and planetary system architectures revealed by Nature so far.

Astronomy & Astrophysics Dr Rosemary Mardling

Explore the interlayer excitons in 2D-semiconductor heterostructure

Atomically-thin 2D semiconductors exhibit strong light-matter interactions and have been considered a candidate for future optoelectronics. In this project, we will stack two different kinds of 2D-semiconductors to form a p-n junction. We will study excitons (composite particles consisting of electrons strongly bound to holes) by employing photoluminescence spectroscopy. We aim to understand the behaviour and dynamics of these excitons in different types of 2D-heterostructures. The project will involve constructing heterojunctions of atomically thin semiconductors, performing optical spectroscopy measurements, and analyzing and interpreting the data.

Condensed Matter Physics Dr Shao-Yu Chen

Exploring the transient sky with a robotic telescope

The Gravitational-wave Optical Transient Observatory (GOTO) is Monash’s own wide-field robotic telescope, deployed since 2017 on the superb observing site on La Palma, in the Canary Islands. The telescope has the primary goal of detecting the electromagnetic counterparts of binary merger events detected with the Laser Interferometric Gravitational-wave Observatory (LIGO). However, in the normal observing mode, GOTO will survey the sky to detect many other types of violent and energetic transients, including supernovae and gamma-ray bursts, as well as more prosaic object such as asteroids and flare stars.

In 2019 the LIGO and Virgo instruments will resume operations at improved sensitivity, that will lead to discovery of many new events, including binary neutron star mergers like the spectacular  GW170817. This honours project will involve remote operation of the telescope; searches for new transient objects; and analysis of data gathered on a wide range of objects. Students will work with extensive archival data gathered over the course of the mission, and compare with detailed source models to measure the properties of distant objects.

GOTO is operated in conjunction with a collaboration of researchers from universities in the UK and Thailand; for more information see http://goto-observatory.org

Astronomy & Astrophysics Associate Professor Duncan Galloway,
Kendall Ackley

Extending polytropic models

Simple polytropic models have many uses in stellar astrophysics. The simple approaches can be extended by adding an equation for the luminosity as well. In this case one can include the H-burning reactions and calculate a luminosity for the model. The idea is to try to construct polytropic models that represent the main phases of stellar evolution around the HR diagram. How can we best simulate a main sequence? Can we simply use the pp and cno cycle reactions? Will it be necessary to make some modifications? For example are all ms stars equally well approximated by polytropes with n=3? Maybe we will need to vary n? Can we simulate a red-giant somehow? Further, what is the best way to solve the Lane-Emden equation? We will investigate using a Runge-Kutta-Fehlberg scheme with a maximum specified error at each step. We can also write the Lane-Emden equation as a differential equation for &zeta as a function of &theta, so that the boundaries are now well known!
Astronomy & Astrophysics Professor John Lattanzio

Experiments on two-dimensional quantum turbulence

Two-dimensional turbulence is even more fascinating than its three-dimensional counterpart. Here, the turbulent energy is predicted to go into the formation of increasingly larger size eddies and vortices in a so-called inverse energy cascade process. Hence 2D turbulence exhibits a peculiar self-organization, giving rise to order out of chaos. This project will involve investigating two-dimensional turbulence in a superfluid atomic gas (a Bose-Einstein condensate). The turbulent behaviour and emergence of order in the superfluid gas will be studied using a number of techniques including particle imaging velocimetry and observation of Kelvin wave dynamics.

Quantum Gases Professor Kris Helmerson

Extra dimensional dark matter

String theory suggests the possibility of new space dimensions opening up at the tera-electron-volt energies. The merit of these extra dimensional models can be tested by their solutions to problems of the standard particle model: the generation of mass, dark matter, neutrino masses, and unification of forces.

Universal extra dimensional models fare well against this test. Among other virtues, they can explain dark matter by the lightest stable Kaluza-Klein particles. In the five and six dimensional models the amount of the lightest Kaluza-Klein particles is consistent with the measured amount of dark matter.

However, there exists no comprehensive analysis of how these models fare against other experimental constraints such as indirect and direct detection bounds, collider limits, precision electroweak variables, rare decays, etc. In this project we attempt this calculation and using these results we perform a viability analysis of this model. <\p>

Particle Physics,
Astronomy & Astrophysics
Professor Csaba Balazs

Extra solar planets

Observations and theory; Stability and long-term evolution of stellar and planetary systems; Tides in planets and stars; Planet formation; The three-body problem; Chaos in conservative systems.

Astronomy & Astrophysics Dr Rosemary Mardling

Extreme outbursts in young stars: An 85-year-old mystery

FU Orionis is a young star whose brightness increased by 6 magnitudes in 1936 and has stayed bright ever since. While this is interpreted as being caused by an increase in the mass accretion rate onto the star, it is unclear what triggered this. Now, new images have revealed a binary companion that might be the “culprit”. In this project we will aim to solve this almost century-old mystery with state-of-the-art computer simulations.

Astronomy & Astrophysics Professor Daniel Price,
Dr Christophe Pinte

Evaluation of biomarker photoacoustic contrast agents

Photo-acoustics is emerging as a clinically relevant biomedical imaging approach in which laser excitation is used to excite a fluorophore leading to the local production of an acoustic wave[1]. Spatial and time resolved detection allows for the building of multi-modal 3D images and videos of native anatomical features in which endogenous fluorophores can be resolved. More recently, nanomaterials have been designed to increase the photoacoustic contrast – and in some cases, “molecular contrast” can be achieved for imaging of particular biomarkers of interest. PA-based imaging and spectroscopy have advantaged over fluorescence imaging in terms of deeper penetration depth and improved resolution, and hence there is increasing interest in developing new contrast materials.

With our collaborators we are looking to develop molecular PA contrast agents for specific proteins, for both imaging and spectroscopic applications. We have recently produced fluorescent antibodies against important proteins which modulate their fluorescence spectra when binding to the target protein[2, 3]. While there are applications for fluorescence monitoring, we are looking to explore fluorescent dyes that also have strong photoacoustic spectra.

We are looking for a talented student to investigate the photo-acoustic properties of a set of candidate dyes, both in solution, incorporated into nanomaterials, and incorporated into antibodies. The project would involve collecting steady-state and time-resolved spectra (absorbance, fluorescence and photo-acoustic) of the dyes in each unique environment, with the potential to test promising agents in animal tissue.  This project is run in conjunction with Dr. Simon Corrie in the School of Chemical Engineering.


1. Reinhardt, C. J.; Chan, J., Development of Photoacoustic Probes for in Vivo Molecular Imaging. Biochemistry 2018, 57 (2), 194-199

2. Fercher, C.; Jones, M. L.; Mahler, S. M.; Corrie, S. R., Recombinant Antibody Engineering Enables Reversible Binding for Continuous Protein Biosensing. ACS Sensors (in press; available online) 2021

3. Islam, J.; Riley, B. T.; Fercher, C.; Jones, M. L.; Buckle, A. M.; Howard, C. B.; Cox, R. P.; Bell, T. D. M.; Mahler, S.; Corrie, S. R., Wavelength-Dependent Fluorescent Immunosensors via Incorporation of Polarity Indicators near the Binding Interface of Antibody Fragments. Analytical Chemistry 2019, 91 (12), 7631-7638

Imaging Physics Dr Alexis Bishop, Dr. Simon Corrie

Femtosecond atomic-scale dynamics on a surface

The advent of scanning tunnelling microscopy more than 30 years ago has allowed for real- space imaging of single atoms and molecules on a surface. Normally, this technique is able to study the equilibrium properties of a system, and does not allow to access real-time ultrafast dynamics occurring at femtosecond timescales. Indeed, the intrinsic time resolution of scanning tunnelling microscopy is dictated by the speed of conventional electronics, which is at best on the order of hundreds of picoseconds. Many processes on surfaces however, such as charge dynamics or vibrations of molecules, can unfold at much faster timescales, below 1 picosecond.

Recent advances in scanning tunnelling microscopy combined with techniques of nonlinear optics, ultrafast photonics and pump-probe spectroscopy have allowed to access ultrafast dynamics of processes on a surface, with real-time sub-picosecond resolution, and, at the same time, real-space single atom resolution [1]. The approach relies on coupling quasi- single-cycle, ultrashort electromagnetic waveforms (e.g., a terahertz, infrared or optical pulse) to the junction of the scanning tunnelling microscope.

The project here consists of investigating structural, charge and magnetization dynamics in photo-active molecular assemblies on surfaces, with sub-picosecond time resolution, and at the scale of a single atom.


[1] T.L. Cocker et al., Nature 539, 263 (2016).

Condensed Matter Physics Dr Agustin Schiffrin

Few and many-body physics in ultracold atomic gases

Ultracold atomic gases have emerged as an ideal platform for investigating the physics of strongly correlated materials in a highly controllable environment. The Theory of Quantum Matter group at Monash University works primarily at the interface between condensed matter physics and the physics of ultracold atoms. We are particularly interested in systems where strong few-body correlations impact the many-body behaviour. As such, we investigate a wide range of topics, including few-body systems, impurities in degenerate quantum matter, systems out of equilibrium, and low-dimensional systems.

Quantum Gases,
Condensed Matter Physics,
Theoretical & Computational Physics
Associate Professor Meera Parish,
Dr Jesper Levinsen

Fluctuations of Quark and Gluon Jets

At centre-of-mass energies above a few billion electron-Volts (GeV), collisions between subatomic particles can produce collimated sprays of nuclear matter, called jets. Essentially, each jet starts out as a quark or gluon receiving a kick in the collision process; this  in turn generates bremsstrahlung of further quarks and gluons at successively longer wavelengths, in a patter reminiscent of fractals, until finally confinement sets in and hadrons are formed. One of the most successful computer models of jet formation, PYTHIA, is developed right here at Monash, and is widely applied e.g. to describe physics processes at the Large Hadron Collider at CERN. PYTHIA uses Markov-Chain Monte Carlo techniques to build up approximations to the bremsstrahlung and hadronisation patterns. But the intrinsic precision is limited. We will consider some of the theoretical uncertainties that arise in these approaches, and propose ways for evaluating and/or improving them. This project is well suited for students with an interest in particle physics phenomenology, computer physics (the parton-shower models are implemented as C++ algorithms), quantum field theory, statistical data analysis, and Markov-Chain / Monte Carlo algorithms.

Particle Physics Associate Professor Peter Skands

Forming Jupiter: exoplanet signatures at submm wavelengths

In this project we will attempt to find newborn planets hidden in their protoplanetary discs by developing and applying a novel algorithm for post-processing Doppler mapping data from the ALMA telescope (an interferometer).

Astronomy & Astrophysics Professor Daniel Price,
Dr Christophe Pinte

Geometric-flow across diffraction patterns in 4D scanning transmission electron microscopy

Breakthrough advances in fast-readout pixelated detectors over the last six years have made it possible to record the full diffraction pattern at each probe position during the scan of an atomically-fine electron beam across a specimen [1]. This million-fold increase in the amount of data that can be recorded per experiment has led to a multitude of new imaging strategies [2] , setting new microscopy records for atomic resolution beyond 0.05 nm [3]. But questions remain about how much real information is present in these large datasets, and how they can be efficiently and effectively processed to reveal structural properties of the specimen.

This project will use numerical simulation to apply a geometric-flow analysis (recently developed for X-ray imaging [4]) to the way the diffraction patterns change as the probe is scanned across the sample. This novel approach is hoped to yield new insights into the information present in the dataset, and perhaps to provide a means of distinguishing long-range and short-range structural features.


[1] M.W. Tate et al., High dynamic range pixel array detector for scanning transmission electron microscopy, Microscopy & Microanalysis 22 (2016) 237,

[2] C. Ophus, Four-dimensional scanning transmission electron microscopy (4D-STEM): from scanning nanodiffraction to ptychography and beyond,Microscopy and Microanalysis 25 (2019) 563,

[3] Y. Jiang et al., Electron ptychography of 2D materials to deep sub-ångström resolution , Nature 559 (2018) 343

[4] D.M. Paganin et al., Single-image geometric-flow x-ray speckle tracking, Physical Review A 98 (2018) 053813

Imaging Physics,
Condensed Matter Physics,
Theoretical & Computational Physics
Dr Scott Findlay, Dr Timothy Petersen, Professor Michael Morgan

Gravitational-wave astronomy

I supervise a wide range of projects in gravitational-wave astronomy. Students in my group use data from the Laser Interferometer Gravitational-wave Observatory (LIGO) in order to understand the fate of massive stars, to probe how binary black holes form, and to understand the nature of matter at the most extreme possible densities. Occasionally, we incorporate other data as well, from gamma-ray burst satellites or from optical surveys of flaring supermassive black holes. This is a fast-evolving field. Shoot me a message if you’re interested in this area and we can discuss potential projects.

Astronomy & Astrophysics Dr Eric Thrane

Gravitational waves illuminate fundamental physics

Standard elementary particles acquire their masses via the mechanism of spontaneous electroweak symmetry breaking. The accompanying cosmological phase transition took place in the early Universe when its temperature fell below the tera-electron-volt scale, and its Hubble horizon was about 23 orders of magnitude smaller than today.

If the electroweak phase transition was strongly first order it proceeded via bubble-nucleation. Collision of the bubble walls containing the broken phase lead to gravitational disturbances, traces of which have been shown to be observable in future gravitational wave experiments such as eLISA.

The aim of this project is to calculate the amplitude and frequency (that is the spectrum) of the gravitational waves created during the electroweak or another phase transition that took place in the early Universe.


[1] "Gravitational waves at aLIGO and vacuum stability with a scalar singlet extension of the Standard Model", Csaba Balazs, Andrew Fowlie, Anupam Mazumdar, Graham White, Phys.Rev. D95 (2017) no.4, e-Print: arXiv:1611.01617

[2] "Multi-peaked signatures of primordial gravitational waves from multi-step electroweak phase transition", Thibault Vieu, Antonio P. Morais, Roman Pasechnik, e-Print: arXiv:1802.10109

[3] "Exotic Gravitational Wave Signatures from Simultaneous Phase Transitions", Djuna Croon, Graham White, JHEP 1805 (2018) 210, e-Print: arXiv:1803.05438

[4] "Primordial Anisotropies in the Gravitational Wave Background from Cosmological Phase Transitions", Michael Geller, Anson Hook, Raman Sundrum, Yuhsin Tsai e-Print: arXiv:1803.10780

[5] "A Cosmological Signature of the SM Higgs Instability: Gravitational Waves", J.R. Espinosa, D. Racco, A. Riotto e-Print: arXiv:1804.07732

[6] "Model Discrimination in Gravitational Wave spectra from Dark Phase Transitions", Djuna Croon, Veronica Sanz, Graham White e-Print: arXiv:1806.02332

Particle Physics Professor Csaba Balazs

Growth and Characterization of 2D Topological Materials

Topological materials, such as topological insulators and topological Dirac semimetals, are a new class of matter that possess new and exciting electronic properties. Allowing a wide range of new physics to be explored including Majorana fermions and the Chiral anomaly to create revolutionary new electronic devices that have the potential to transport charge through one-dimensional edge modes without dissipation.

In this project you will learn how to grow new two-dimensional topological materials via molecular beam epitaxy. A technique that allows the precise growth and control of epitaxial large area films. This will involve preparing substrates and performing growths, during growth you will utilize in-situ diffraction techniques to confirm crystallinity and sample quality.

After successfully growing these materials you will employ low-temperature scanning tunneling microscopy (STM) to study the electronic properties. This will involve studying with atomic precision the electronic structure at edges and defects with STM at Monash University.

If you have any questions, please contact Dr Mark Edmonds at mark.edmonds@monash.edu or Prof. Michael Fuhrer at michael.fuhrer@monash.edu.

Condensed Matter Physics Dr Mark Edmonds,
Professor Michael Fuhrer

"Hamiltonian learning": Machine learning for real time quantum measurements

Spinor Bose-Einstein condensates make excellent magnetometers: ultracold cold spins have vanishing thermal noise and couple strongly to magnetic fields. We use lasers to measure the BEC state and therefore measure the field. Bright beams make better measurements, but also toast the BEC faster. Too bright a beam and we have burnt off the BEC before the field has evolved it much. Too dim a beam and our measurement is swamped by noise. Do we leave the beam off and then pulse it on? How long to wait? How long a pulse? The answers to these questions depend on the strength of the magnetic field and how rapidly it is changing... and these things we know only when we start to measure! In this project you'll use ideas from machine learning and Bayesian estimation to apply adaptive and non-adaptive measurement protocols to a BEC magnetometer.

Quantum Gases Dr Lincoln Turner

Helium-rich massive stars in Globular Clusters

Globular clusters are some of the more spectacular yet mysterious components of galaxies. They are usually old objects with some 100,000 old stars. Their exact origin and formation is not known, however. Whereas it was once assumed they would form monolithically in one star formation event from just a single chemically homogeneous gas cloud, modern astronomical observations allowed us to identify at least two, sometimes more, distinct stellar populations within most of them, visible in the colour-magnitude diagram. These different populations are chemically very similar in some chemical elements, but distinctly different in others. One of the key differences is in their helium enrichment. This is what changes the location of the low-mass stars in the colour-magnitude digram, as observed. But how does it affect more massive stars, especially those that make supernovae?

The goal of this project is to model the evolution massive supernova progenitor stars, of globular cluster chemical composition, but with varying degrees of helium enrichment. The project will use a modern stellar evolution code to model evolution, nucleosynthesis, and supernova explosions of massive stars. Depending on project progress, an extension could be to compare to models of rotating massive stars and their nucleosynthesis. The results will be compared to the observational data.

Astronomy & Astrophysics Professor Alexander Heger,
Associate Professor Amanda Karakas

How binary companions affect supernovae

At the ends of their lives, massive stars explode in supernovae.  There is a huge observational diversity of supernovae, and some are quite challenging to explain.  For example, some supernova remnants indicate that the supernova progenitor was likely stripped by interacting with a companion, but no companion is observed.  How is that possible?  This project will use a combination of binary population synthesis and hydrodynamical modelling to resolve such mysteries.


Hirai et al., https://ui.adsabs.harvard.edu/abs/2020arXiv200805076H;
Mandel et al., https://ui.adsabs.harvard.edu/abs/2020arXiv200703890M

Astronomy & Astrophysics Dr. Ryosuke Hirai, Professor Ilya Mandel

How fast do old stars rotate inside?

The Kepler satellite mission became famous for finding hundreds of new planets around stars. To do so, it had to monitor them in minute detail, including all variations and oscillations of the star. Amazingly, the data was good enough to use seismology, similar to what we do on earth to determine its interior structure, or for the sun ("helioseismology "), to determine the interior structure and rotation rate of evolved - old - stars that approach the end of their life. For the Sun, we can easily observe how fast it rotates on the surface, and we know that the same rotation rate, on average, is maintained all the way to the centre. But for all other stars, the interior rotation rate was not known to date. But now we have observations. The big questions is whether our current model for transport of angular momentum and stellar evolution is good enough to explain this data. Having this data is a unique new opportunity to test physical models for the action of rotation inside stars.

The goal of this project is to model the evolution of a star like the long past its current age until the Red Giant and Horizontal Branch evolution phases. The project will use a modern stellar evolution code, and the code would also be modified to test different physics models for the action of magnetic dynamos and hydrodynamic instabilities due to rotation. The results will be compared to the observational data.


[1] A. Heger, S. E. Woosley and H. C. Spruit, "Presupernova Evolution of Differentially Rotating Massive Stars Including Magnetic Fields ", The Astrophysical Journal, Volume 626, Number 1 (2005).

[2] H. C. Spruit, "Dynamo action by differential rotation in a stably stratified stellar interior ", Astronomy & Astrophysics, Volume 381, Number 3 (2002).

Astronomy & Astrophysics Professor Alexander Heger,
Paul Cally

Hyper-velocity stars - the products of tidal disruption?

We will consider the change to the stellar structure and evolution that occurs when a star wanders too close to a black hole, asking whether these features are reflected in the population of hyper-velocity stars that are thought to have had a past encounter with the supermassive black hole in the Milky Way.

Astronomy & Astrophysics Professor Daniel Price,
Professor Alexander Heger

Imaging electron waves on the surface of a 2D semiconductor

Scanning tunnelling spectroscopy (STS), combined with scanning tunnelling microscopy (STM), is a powerful tool to explore a material's electronic properties in real space, as it allows probing the local electronic density of states (DOS) with atomic resolution. STS can visualize spatial modulations of the electronic states, and capture collective phenomena like standing wave patterns originating from electrons scattering off defects. Furthermore, changes in the DOS can be used to investigate electronic phase transitions.

In this project you will conduct an extensive study of the transition metal dichalcogenide MoS2 vis STM&STS. You will acquire data on the freshly cleaved material in the Fuhrer labs, learning the fundamentals of scanning probe microscopy by working with state-of-the-art equipment at cryogenic temperatures. You will investigate the behaviour of the electrons around defects (like atomic vacancies), and also verify the possibility of inducing a local structural phase transition (from 2H to 1T) in the crystal by applying a strong electric field. If time allows, you will study the effect of alkali metal deposition on such a phase transition.

If you have any questions, please contact Dr Iolanda Di Bernardo at iolanda.dibernardo@monash.edu, Dr Mark Edmonds at mark.edmonds@monash.edu or Prof. Michael Fuhrer at michael.fuhrer@monash.edu.

Pictured: Electron waves on the surface of ZrSiS imaged in Fuhrer lab, doi:10.1021/acs.nanolett.7b02307

Condensed Matter Physics Dr Iolanda Di Bernardo,
Dr Mark Edmonds,
Professor Michael Fuhrer

Impulse-equivalent pulse trains and arrays

Functions that mimic the sharp sifting property of the discrete Dirac-delta are highly valued for their practical use in digital communication, many forms of imaging and for data encryption. A delta function has sharp localisation in the spatial domain (a perfect point spread function, or psf) and is exactly flat in the Fourier domain (a perfect modulation transform function, or MTF). The aperiodic auto-correlation for impulse-equivalent 1D sequences of finite length (or as nD arrays) have the largest possible peak value at zero relative shift, with minimal, preferably zero, correlation for all off-peak shifts.  The quality of a sequence is measured by its discrimination factor (peak to maximum off-peak ratio) and its merit factor (the ratio of peak value squared to the sum of all squared off-peak values). The sequence elements should comprise small integer values (e.g. -1 and +1 entries or binary 0, +1 entries) and should also avoid having too many zero terms to keep their energy efficiency high. The Barker sequences are the outstanding exemplars, but these are known to have a maximum length of just 13 elements,  viz. [+++++--++-+-+]. Longer sequences can be found by adopting a wider range of integer values (e.g. the Huffman sequences) or using Moharir sequences that interleave multiple arrays, each built with a ternary alphabet (-1, 0, +1). These sequences work well, but they either have lower efficiency or prove to be less robust when they are recovered in a noisy environment.

This project will build long, impulse-equivalent sequences based on Singer difference sets. Each Singer set is a binary sequence that is exactly spectrally flat and has small off-peak auto-correlation values. The length L of a Singer sequence can be quite large, L = p2 + p + 1 when p is prime. The Singer sequences are, unfortunately, quite sparse, containing just p+1 non-zero elements. However, the complement of each Singer set is also exactly spectrally flat. Pairs of Singer sequences of length L can then be combined to produce a sequence of length L that has maximal efficiency and has high quality auto-correlation. These 1D sequences, in turn, can be used to construct nD arrays with strong auto-correlation properties. The project will examine optimal ways to combine 1D Singer sequences and use these to build nD impulse-equivalent arrays.


[1] Singer, J., 1938, A theorem in projective geometry and some applications to number theory, Trans. Amer. Math. Soc., 43, 377-385.

[2] Barker, R. H., 1953, Group synchronisation of binary digital systems, In Communication Theory, (Ed.) W. Jackson (London, Butterworths).

[3] Hunt, J. N. and Ackroyd, M. H., 1980, Some integer Huffman sequences, IEEE Trans. Information Theory, vol. 26, no. 1, 105-107, 1980.

[4] Moharir, P.S., Subba Rao, K., 1997, Non-binary sequences with superior merit factors, IETE, J. Res, 1:, 49-53.

[5] Tirkel, A., Cavy B. and Svalbe, I., 2015, Families of multi-dimensional arrays with optimal correlations between all members, Electronics Letters, 51(15) 1167-1168.

[6] Svalbe, I., Ceko M. and Tirkel, A., 2018, Large families of ‘grey’ arrays with perfect auto-correlation and optimal cross-correlation, DCGI, Vienna, Austria, September, 2017, under review for JMIV.

Imaging Physics Dr Imants Svalbe,
Andrew Tirkel

Inferring supernova physics from the production of heavy elements

Massive stars go through various burning stages during their lives and eventually develop on "onion shell" structure of layers composed of successively heaver elements towards the interior with an iron core at the centre. Eventually the iron core collapses to a neutron star or black hole, and in many cases, the envelope is ejected in a supernova explosion. The dividing line between successful explosions and black hole formation is still not completely clear. Theoretical models [1] are still beset with uncertainties. Observations of supernova progenitors suggest an upper mass limit for supernovae of about 15-18 solar masses [2], but complementary evidence is needed to substantiate this. Investigating the contribution of supernova explosions to the inventory of heavy elements in the galaxy could help further constrain the upper mass limit for supernova explosions. Interestingly, it seems that explosions of massive stars above 20 solar masses are required to produce sufficient amount of some elements like oxygen [3]. However, this conclusion is sensitive to the assumed supernova explosion energies and the "mass cut" between the neutron star and the ejecta.

In this project, we shall reinvestigate how the contribution of certain elements and radioactive isotopes (Fe, O, Al-26) depends on the fraction of massive stars that go supernovae instead of forming a black hole. We will use a simple Python-based model for the progenitor-dependence of supernova explosion properties [1] to compare the relative production of Fe to other "marker" elements for massive stars.


[1] Mueller, Heger, Liptai & Cameron 2016, MNRAS 460, 742

[2] Smartt 2015, PASA 32, e16

[3] Woosley & Brown 2013, ApJ 769, 99

Astronomy & Astrophysics Dr Bernhard Mueller,
Professor Alexander Heger

Interplay between Dirac electrons and magnetic textures in topological insulators

Topological insulators (TI) represent a new state of quantum matter. TIs have insulating bulk (like an ordinary insulator) and exotic metallic surface states. These states are described by a relativistic-like Dirac equation for massless particles that models their unconvenitional behaviour. In particular, the direction of electron spin for Dirac electron is perfectly correlated (or locked) with the direction of its momentum. That is why interplay between Dirac electrons and magnetism (such as depositing magnetic atoms to the surface or interfaces (sandwich-like structures) between TI and magnets) is very rich, and this rich area is the focus of this research topic.


Erika K. Carlson, 'An Intrinsically Magnetic Topological Insulator', American Physical Society (2020)

H.M. Hurst, D.K. Efimkin, J. Zang, V. Galitski - Phys. Rev. B 91, 060401 (2015)

Quantum Gases,
Condensed Matter Physics,
Theoretical & Computational Physics
Dr Dmitry Efimkin

Is dark matter superfluid light?

There are numerous observations shedding light on the properties of dark matter, however its decomposition is unknown. Based on its known properties, we examine whether dark matter can be superfluid light. Our speculation is motivated by the recent observations of Bose-Einstein condensation of photons [1] and by the successes of the bosonic star dark matter models [2].

In this project, we examine the quantitative details of the above proposal. Under what conditions do photons condense in the early Universe? Is the condensate "dark "? Is it destroyed by ordinary matter? Does the average energy density trapped in the condensate match the measurements? Do vortices in the condensate correspond to galaxies, clusters or larger observed structures? Can the mass distribution of galaxy clusters be explained? Do the galactic rotation curves agree with this model?

Based on the general properties of Bose-Einstein condensates and the standard (ΛCDM) cosmological model each of these questions can be quantitatively answered [3,4].


[1] J. Klaers, J. Schmitt, F. Vewinger and M. Weitz, "Bose–Einstein condensation of photons in an optical microcavity" Nature, Volume 468, Issue 7323 (2010)

[2] J.-W. Lee, "Is dark matter a BEC or scalar field? ", arXiv:0801.1442 .

[3] M. Morgan and R. Yu, "Vortices in a rotating dark matter condensate", Classical and Quantum Gravity, Volume 19, Number 17 (2002).

Particle Physics,
Quantum Gases,
Theoretical & Computational Physics
Professor Csaba Balazs,
Professor Michael Morgan

Light-transformed materials

Topological materials – with their unique electronic properties dictated by the topology of their quantum mechanical states – are on the verge of revolutionising the fields of advanced materials, electronics and spintronics. For example, some of these materials can transport charge at very low resistance, potentially leading to future applications in low-power electronic technologies.

The project here consists of probing and manipulating – at ultrafast femto and picosecond timescales – the topological phases of matter using quasi-single-cycle, ultrashort electromagnetic waveforms (e.g., terahertz, infrared or visible ultrashort pulses). Systems of interest will consist of 2D and 3D topological insulators, transition metal dichalcogenides and Dirac semimetals (e.g. graphene). The project will also focus on numerical modelling of ultrafast photoinduced changes of electronic properties in these advanced materials.

Condensed Matter Physics Dr Agustin Schiffrin, Dr Gary Beane

Low-dimensional organic nanostructures with topological electronic properties

Topological insulators are a novel class of materials with non-trivial electronic properties. Electrons at the boundaries of these materials can propagate without dissipating energy [1] . So far, topological phases have only been demonstrated in inorganic materials. The goal of this project is to synthesise and characterise low-dimensional organic nanostructures, in which the atomic-scale morphology and electronic structure give rise to non-trivial topological electronic states [2] . The project will exploit metal atoms and organic molecules as building units in approaches of supramolecular chemistry applied on surfaces, to achieve ultimate structural and electronic control at the single atom level [3] . The motivation of stems from the bottom-up design of advanced materials, where novel electronic signatures will be applicable for the development of dissipation-less electronics, spintronics and solid-state-based quantum information processing.

Systems of interest will be prepared in ultrahigh vacuum (UHV) and characterised in situ by means of low-temperature scanning tunneling microscopy (STM) and spectroscopy (STS), as well as non-contact atomic force microscopy (ncAFM). X-ray-based measurements performed at the Australian Synchrotron will provide complementary chemical characterisation. Optical techniques will allow for optical probing of topological electronic phases.


[1] M. Z. Hasan and C. L. Kane, "Colloquium: Topological insulators", Reviews of Modern Physics, volume 82, 3045 (2010).

[2] Z. F. Wang et al, Nature Communications volume 4 (2013).

[3] Johannes V. Barth, "Molecular Architectonic on Metal Surfaces", Annual Review of Physical Chemistry, volume 58, 375-407 (2007).

Condensed Matter Physics Dr Agustin Schiffrin

Magnetic fields in star formation

When we model star formation in the computer, we usually chop out the star itself and replace it with a point mass, or `sink particle’. However, this is problematic in the presence of magnetic fields because it involves punching a hole in the magnetic field, thus creating magnetic monopoles which should not exist. The aim of this project is to find a better boundary condition for the magnetic field near sink particles, based on ideas from modelling magnetic fields in the solar system, in order to carry out more consistent and stable simulations of star formation.

Astronomy & Astrophysics Professor Daniel Price

Magnetoresistance of semiconductors in the non-linear regime

The change of electrical resistance in a magnetic field (i.e., the magetoresistance) is typically rather small in many materials, but it can have important technological applications when it is sizeable. For instance, the "giant magnetoresistance " of magnetic multilayer structures provides the basis for magnetic sensors used in hard disks and other devices. However, magnetism is not the only route to a large magnetoresistance. Material inhomogeneities or the sample geometry can also generate a substantial magnetoresistance in non-magnetic systems [1]. It has also been demonstrated that a similar effect can be achieved in a semiconductor subjected to a high electric field, where the electrical transport is no longer ohmic [2]. The aim of this project is to determine whether the inhomogeneous electric field present in this non-linear transport regime is sufficient to produce a large magnetoresistance or whether something further is required.


[1] M. M. Parish, P. B. Littlewood, Non-saturating magnetoresistance in heavily disordered semiconductors, Nature volume 426, number 6963, 2003

[2] M. P. Delmo et. al., Large positive magnetoresistive effect in silicon induced by the space-charge effect, Nature volume 457, number 7233, 2009

Condensed Matter Physics,
Theoretical & Computational Physics
Associate Professor Meera Parish

Making carbon in the universe: implications for life?

This project will look at the production of carbon by red-giants. The aim will be to take the results from detailed stellar evolution calculations and include these in a new code which simulates the evolution of an entore Galaxy. With some simple approximations, we can produce a "population synthesis" code which can model a large population of stars. Then we can investigate the effect of binary stars, mass-transfer from one to another, the effect of mass-loss etc etc. It is possible, if time permits, to also include other species so we can look at the production of Oxygen also. This has many implications for the appearance of life in the Universe - planets forming in a carbon-rich environment are very different to those forming in a oxygen-rich environment!

This would be a good project for someone who wanted to improve their skills at computer programming: it will start with a very simple code to which you will add more and more and build it into a substantial piece of work.

Astronomy & Astrophysics Professor John Lattanzio,
Associate Professor Amanda Karakas

Merging binary black holes in globular clusters

In February of 2015, the LIGO observatory announced the first detection of gravitational waves from a pair of merging black holes.   Since then, a number of scenarios for forming such binary black holes have been proposed.  One involves dynamical interactions in globular clusters.  3-body encounters could tighten black-hole binaries, bringing them to merger.  They may also be responsible for the ejections of very fast (a few hundred km/s) stars from clusters, which could be probed with the Gaia mission.  In this project, we will analyse the dynamics of globular clusters and investigate gravitational-wave signatures and stellar ejections as tracers of such dynamics.


Rodriguez et al., http://adsabs.harvard.edu/abs/2016ApJ...824L...8R ; Mandel & Farmer, http://adsabs.harvard.edu/abs/2018arXiv180605820M

Astronomy & Astrophysics Professor Ilya Mandel,
Dr Eric Thrane

Miniaturisation of Electrical Devices for MBE growth and in-situ Transport Studies

Fuhrer, Hellerstedt and Edmonds have developed unique-in-the-world techniques to measure the electrical properties, such as resistivity and Hall effect, of a thin film of material during growth by molecular bean epitaxy (MBE) as well as post-growth without removing the sample from vacuum. This allows for studies of exotic materials that may be unstable on removal from vacuum. The current techniques use electrical devices on the millimeter length scale. Yet, many interesting and exotic quantum transport phenomena such as ballistic transport and spin field-effect transistors require devices on the micrometer or even nanometer length scale to be observed. This project will have two aims:

(1) Develop fabrication techniques to miniaturise these devices, whilst still maintaining a clean substrate surface capable of growing high-quality MBE films. This part of the project will utilise the fabrication facilities at the Melbourne Centre for Nanofabrication such as lithography, metal deposition and atomic-layer deposition, as well as electron beam lithography in Fuhrer's laboratory.

(2) Carry out MBE film growth and transport measurements on these miniaturised devices using the combined low-temperature scanning tunnelling microscopy and MBE system within the Fuhrer laboratory.

Condensed Matter Physics Professor Michael Fuhrer,
Dr Mark Edmonds,
Dr Bent Weber,
Dr Jack Hellerstedt

Mixing at convective boundaries in 3D and 1D

Stars are not spherically symmetric. One of the most important multi-dimensional phenomena inside stars is convective overturn, which is driven by buoyancy. Stellar evolution models are forced to treat this phenomenon in spherical symmetry by means of effective recipes such as the "mixing-length theory". Such an approach cannot do full justice to the multi-dimensional nature of convective flow. Mixing-length theory often describes the rapid and efficient mixing within convective zones quite well, but it is particularly difficult to adjust or extend it to reproduce what is going on at convective boundaries. Here, the interaction of convective plumes with a stable region can lead to wave excitation and complicated mixing processes. Various recipes have been proposed to treat these phenomena in stellar evolution models [1,2].

Thanks to growing computer power, we can now simulate convection inside stars in three dimensions in certain cases and use these simulations to test and improve one-dimensional recipes for mixing. In this project, we will focus on the process of “turbulent entrainment” in the late stages of shell convection in massive stars. We will compare the results of recent 3D simulations [3,4] to standard recipes for convective boundary mixing in stellar evolution codes [2] and to more sophisticated one-dimensional turbulence models [5] to determine how these one-dimensional models can be calibrated to correctly reproduce the growth of convective shells by entrainment.


[1] Viallet, Meakin, Prat & Arnett 2015, Astronomy & Astrophysics 580, 61

[2] Freytag, Ludwig & Steffen 1996, Astronomy & Astrophysics 319, 497

[3] Müller, Viallet, Heger & Janka 2016, The Astrophysical Journal 833, 124

[4] Meakin & Arnett 2007, The Astrophysical Journal 667, 448

[5] Wuchterl & Feuchtinger 1998, Astronomy & Astrophysics 340, 419

Astronomy & Astrophysics Dr Bernhard Mueller,
Professor Alexander Heger,
Professor John Lattanzio

Mixing in red giants – attacked with telescopes and computers

Red-giants are fascinating stars and they continue to provide us with problems that as yet have no solutions. One of these concerns mixing as they stars climb the giant branch. The standard models do not predict as much mixing as is seen in the data. We recently discovered a mechanism that is likely to be involved in the solution of this problem, but there are aspects of the mechanism that are still unknown. We are trying to tackle this problem by combining observations and theoretical models. We will be taking new data in December for stars in the globular cluster NGC1851.

This project involves both running stellar models, so that the student investigates the theory of thermohaline mixing, as well as reducing data taken with Australia's largest telescope. This will likely involve a trip to the Australian Astronomical Observatory (AAO) to work with the co-supervisors in Sydney. The aim is to compare the observed data with the models run at Monash.


[1] Lardo, et al., 2012, Astronomy and Astrophysics, 541, p141

[2] Angelou et al., 2012, Astrophysical Journal, 749, p128

[3] Eggleton et al., 2006, Science, 314, p1580

Astronomy & Astrophysics Professor John Lattanzio,
Dr Simon Campbell

Modelling black hole birth kicks

When massive stars undergo supernovae and collapse into neutron stars or black holes, they may asymmetrically eject mass, leading to a recoil kick.  Such birth kicks for black holes play an important role in the evolution of X-ray binaries and possible future gravitational-wave sources.  However, they are difficult to measure through direct observations.  In this project, we will use a combination of supernova explosion models and indirect observational constraints to constrain black hole natal kicks.


Mirabel, http://adsabs.harvard.edu/abs/2016arXiv160908411M,
Mueller et al., http://adsabs.harvard.edu/abs/2016MNRAS.460..742M ,
Mandel & Mueller, https://ui.adsabs.harvard.edu/abs/2020arXiv200608360M

Astronomy & Astrophysics Professor Ilya Mandel,
Dr Bernhard Mueller

Modelling the electronic structure of low-dimensional organic nanostructures on surfaces

Supramolecular and metal-organic self-assembly on surfaces holds promise for the synthesis of functional low-dimensional nanostructures with ultimate atomic-scale precision [1] . This approach consists of depositing atoms and functionalised organic molecules onto clean surfaces, in a controlled environment, to achieve well-defined configurations via programmed inter-adsorbate and adsorbate-surface interactions.

Potential functionality of these nano-assemblies arise from their atomic-scale electronic structure, which is dictated by quantum mechanics. Understanding and predicting such electronic structure is non-trivial, given the typically large size of the unit cell of these many- body systems. Density functional theory (DFT) [2] offers a viable numerical method for determining the energy-dependent electronic density in such systems, allowing to understand and predict their morphology and electronic properties at the atomic scale.

The project here consists of using computational DFT tools (and other complementary numerical approaches) for determining the atomic-scale morphology and electronic structure of low-dimensional nanostructures on surfaces. Systems of interest will consist of 1D and 2D metal-organic frameworks on metals, semiconductors and atomically thin materials. In particular, these systems are relevant for the design of solid interfaces with functionality in photovoltaics, photocatalysis, molecular nanoelectronics and molecular magnetism. This project will be co-supervised by Dr. N. Medhekar (Department of Materials Science and Engineering).


[1] Johannes V. Barth, "Molecular Architectonic on Metal Surfaces", Annual Review of Physical Chemistry, volume 58, 375-407 (2007).

[2] R. O. Jones, "Density functional theory: Its origins, rise to prominence, and future", Reviews of Modern Physics, volume 87, 897 (2015).

Condensed Matter Physics Dr Agustin Schiffrin,
Dr Nikhil Medhekar

Modelling the interaction of atoms with an optically trapped microsphere

The interaction of light with matter invariable involves the exchange of momentum. This exchange of momentum can be exploited to trap and remotely manipulate particles from the size of individual atoms to objects at the micron scale. Typically, the study of optical forces on these vastly different size objects is performed independently. The purpose of this project is to investigate the combined effect of these two, seemingly different, applications of optical forces. In particular, the project will involve modelling the optical field at the surface of a microsphere trapped by a focused laser beam and studying the interaction of laser cooled atoms with the field at the surface of the microsphere.

Imaging Physics Professor Kris Helmerson

Neutron star mergers

Neutron star mergers are thought to be the origin of short gamma-ray bursts. They are also prime candidates for observations with gravitational wave detectors such as LIGO. In this project we will try to adapt our 3D simulation code to model neutron star mergers in 3D with the aim of understanding the physics of these extreme stellar objects.

Astronomy & Astrophysics Professor Daniel Price

Nucleosynthesis during the core helium flash

After a star exhausts its central H supply it becomes a red-giant. For low mass stars this He core becomes electron-degenerate and continues to heat. When the temperature reaches about 100 million degrees we find helium burning is ignited. But due to the degenerate equation of state, this is almost explosive. The star generates about one billion times the energy of our Sun, but just for a few days. The structure of the star changes dramatically, of course. Although the details are very complicated, we know that most stars survive this phase, as we see them in the next stage of their lives.

Standard calculations with the standard assumptions (hydrostatic equilibrium, instantaneous convective mixing) seem to get through this phase, although clearly the details require multi-dimensional hydro-dynamical calculations. Nevertheless, since models made with these assumptions match the later phases, these standard assumptions must be OK for most stars. In this project you will evolve stars through this phase using a stellar evolution code, investigating the uncertainties in the calculations. Further, a separate code calculates the detailed nuclear reactions occurring and we will investigate the reactions and possible mixing mechanisms. Are there observational tests we can apply to the models?

Astronomy & Astrophysics Professor John Lattanzio

On-surface design of organic nanostructures with tailored optoelectronic functionality

On-surface supramolecular chemistry – through which molecular and atomic units interact and form well-defined geometries – holds promise for the fabrication of nanostructures with atomic-scale precision and tailored electronic properties [1] . This project consists of using approaches of supramolecular chemistry to synthesise low-dimensional organic and metal- organic nano-assemblies on surfaces. The goal is to achieve solid-state interfaces with atomically precise morphologies, resulting in well-defined electronic structure, and with potential for efficient light harvesting and/or emission. The motivation stems from designing materials for efficient and cost-effective optoelectronic applications [2] .

Systems of interest will consist of organic and metal-organic nano-assemblies on noble metal surfaces and thin insulating films. These systems will be prepared in ultrahigh vacuum (UHV) and characterised in situ by means of low-temperature scanning tunneling microscopy (STM) and spectroscopy (STS), as well as non-contact atomic force microscopy (ncAFM). X-ray- based measurements performed at the Australian Synchrotron will provide complementary chemical characterisation. Optical techniques will provide optoelectronic characterisation. International collaborations will allow for time-resolved studies of ultrafast photo-induced charge dynamics.


[1] Johannes V. Barth, "Molecular Architectonic on Metal Surfaces", Annual Review of Physical Chemistry, volume 58, 375-407 (2007).

[2] Gregory D. Scholes, Graham R. Fleming, Alexandra Olaya-Castro, and Rienk van Grondelle, "Lessons from nature about solar light harvesting", Nature Chemistry, volume 3, 763-774 (2011).

Condensed Matter Physics Dr Agustin Schiffrin

Optical photoacoustic tomography sensing

Photoacoustic techniques are seen as the next generation of imaging for biological systems [1]. Photoacoustic tomography allows structures throughout a volume of scattering tissue to be visualized using light, which has many advantages over conventional X-ray or MRI techniques. The main limitation is the lack of high spatial resolution sensors for detecting ultrasound waves. This experimental project will optimize a recently developed optically-based sensor, utilizing a conventional camera, to provide high-resolution, time resolved ultrasound detection of a large region without requiring scanning. A tomographic inversion algorithm will be used to reconstruct the sensing volume.


[1] Laufer J., Zhang E., Raivich G., Beard P., Three-dimensional noninvasive imaging of the vasculature in the mouse brain using a high resolution photoacoustic scanner. Applied Optics, 48, 10, D299-D306, 2009

Imaging Physics Dr Alexis Bishop

Optical Lattices for ultracold atoms

Ultracold atoms can be trapped in an optical lattice, the periodic potential formed by optical standing waves. The atoms in the optical lattice exhibit behavior similar to electrons in an ideal crystal. By including the interaction of the atoms, such a system can be used to study many-body phenomena traditionally in the realm of solid-state physics. This project will investigate the emergence of many-body behaviour of particles as various parameters such as interaction strength and disorder as varied in this model system.

Condensed Matter Physics
Professor Kris Helmerson

Optical site testing for future robotic telescopes

Demand for future optical observing facilities dedicated to survey and fast-response followup is only likely to increase. One such facility is the Gravitational wave Optical Transient Observatory (GOTO), a project aimed at detecting the electromagnetic counterparts of binary inspiral events detected with the Laser Interferometric Gravitational-wave Observatory (LIGO). GOTO is hoped eventually to consist of a pair of instruments, one in La Palma, Canary Islands, and one in Australia. This project is focussed on measurements of the astronomical "seeing", both the degree of blurring of stellar images by the atmosphere, and the brightness of the sky. Portable test equipment will be developed and tested in the lab, and then deployed at candidate sites to obtain empirical values for the seeing, and verify the remote measurements. The student will visit the observing sites to assist in data collection, and analyse the CCD data to estimate the seeing. Experiments at existing telescope sites will also be necessary to calibrate the test equipment.

Further reading: Hotan et al.. 2013, http://dx.doi.org/10.1017/pasa.2012.002

Astronomy & Astrophysics Associate Professor Duncan Galloway,
Professor Karl Glazebrook (Swinburne)

Optical trapping of microscopic water droplets for single molecule studies

Techniques for optically observing single molecules are extending and even changing our understanding of molecular processes in biology. Often, it is desirable to follow the dynamics of a single molecule for several seconds or longer. Methods have been developed to immobilize and isolate or confine single molecule in order to study their dynamics on such long time scales. One such approach is to confine the molecule of interest in a microscopic water droplet immersed in an immiscible background fluid, and then trap the water droplet using optical tweezers. For a sufficiently small water droplet, the molecule of interest will remain within the detection volume of a confocal microscope allowing continuous measurement of the molecule's behaviour. This approach has advantages over other approaches for immobilizing single molecules, such as surface attachment - the molecule is free to diffuse within the water droplet away from an uncharacterized surface. The goal of this project will be to develop an apparatus capable of trapping and manipulating microscopic water droplets containing single molecules and studying the behaviour of the single molecules. In addition to the development of the necessary optical technologies for such studies, microfluidic-based approaches will be investigated for generating single, microscopic water droplets on demand.

Condensed Matter Physics Professor Kris Helmerson

Periodically driven many-body quantum systems

Periodic driving of a system endows it with a temporal periodicity, much like crystal lattices that have a spatial periodicity. Yet, periodic driving yields a variety of tuning knobs which can in principle allow one to investigate physics that is difficult to access in any equilibrium system. Indeed, even though there is only one time dimension, one can even make the system equivalent to higher-dimensional spatial lattices. This project will explore some of the new physics that can emerge in periodically driven many-body quantum systems.

Quantum Gases,
Condensed Matter Physics,
Theoretical & Computational Physics
Associate Professor Meera Parish,
Dr Jesper Levinsen

Phase contrast imaging with vortex lattices

We are looking for an enthusiastic student to perform research on practical applications of optical vortex lattices [1, 2] for interferometry [3, 4], to expand the scope of contemporary singular optics.  In prior work [5] we have demonstrated quantitative ‘singularimetry’ [6], where a 3-beam lattice of optical vortices directly measured phase shifts imparted by a specimen in one arm of a 3-beam Mach-Zehnder interferometer.  For certain microscopy techniques, strong radiation-matter interactions and short wavelengths may prohibit such uses of beam splitters.  For example, in electron holography, 3-beam vortex lattices have recently been realized, which could enhance the precision of nanoscale electromagnetic field mapping [7, 8].  However, restricting just one electron beam to pass through a sample poses significant engineering challenges.  We have hence derived a different approach, where all beams pass through the sample. To this end, a new differential form of singularimetry was developed, utilising vortices and gradient singularities as topological fiducial markers in a structured-illumination context.  This approach analytically measures phase gradients imparted by refracting specimens, yielding quantitative information that is local and deterministic.  Recent light-optics experiments of this kind have demonstrated that singularity lattices can detect subtle specimen variations with high precision [9].

We would now like to create new capabilities for these experiments, by exploring the non-trivial movement of oppositely charged vortices in response to specimen attenuation variations.  Similarly, we want to extend these ideas to non-vortical singular points in more general structured optical wave-fields, with applications for other forms of radiation.  The project is open to theoretical, computational and/or experimentally inclined students.


[1] K. W. Nicholls and J. F. Nye, "Three-beam model for studying dislocations in wave pulses", Journal of Physics A: Mathematical and General, volume 20, 4673-4696 (1987).

[2] Jan Masajada and Bogusława Dubik, "Optical vortex generation by three plane wave interference", Optics Communications, volume 198, 21-27 (2001).

[3] Jan Masajada, "Small-angle rotations measurement using optical vortex interferometer", Optics Communications, volume 239, 373-381 (2004).

[4] Agnieszka Popiolek-Masajada, Monika Borwinska, and Boguslawa Dubik, "Reconstruction of a plane wave’s tilt and orientation using an optical vortex interferometer", Optical Engineering, volume 46, 073604-073608 (2007).

[5] Samuel A. Eastwood, Alexis I. Bishop, Timothy C. Petersen, David M. Paganin, and Michael J. Morgan, "Phase measurement using an optical vortex lattice produced with a three-beam interferometer", Optics Express, volume 20, issue 13, 13947-13957 (2012).

[6] M. R. Dennis and J. B. Gotte, "Beam shifts for pairs of plane waves", Journal of Optics, volume 15, 014015 (2013).

[7] T. Niermann, J. Verbeeck, and M. Lehmann, "Creating arrays of electron vortices", Ultramicroscopy, volume 136, 165-170 (2014).

[8] C. Dwyer, C. B. Boothroyd, S. L. Y. Chang, and R. E. Dunin-Borkowski, "Three-wave electron vortex lattices for measuring nanofields", Ultramicroscopy, volume 148, 25-30 (2015).

[9] Timothy C. Petersen, Alexis I. Bishop, Samuel A. Eastwood, David M. Paganin, Kaye S. Morgan, and Michael J. Morgan, "Singularimetry of local phase gradients using vortex lattices and in-line holography", Optics Express, volume 24, issue 3, 2259-2272 (2016).

Imaging Physics,
Condensed Matter Physics,
Theoretical & Computational Physics
Dr Timothy Petersen,
Dr Alexis Bishop

Photoacoustic detection of deep targets

There is much interest in being able to detect stroke affected regions in the human brain without using dangerous ionising X-rays or expensive MRI or CT techniques. Recently developed photoacoustic techniques have the ability to provide visualisation of the vascular structure as well as measurements of other properties. For the photoacoustic technique, an intense pulsed laser beam, with a wavelength that is absorbed by the haemoglobin in red blood cells, illuminates the skull, which strongly diffuses the light without appreciable absorption. The blood cells in the vessels of the brain absorb the scattered light, and generate an outward pressure pulse. The pressure pulse can travel largely unimpeded through the brain and skull to the surface where it can be detected by a pressure transducer.  By observing the pressure signal at different delay times, images of structures at different depths in the brain can be made.

This experimentally-based project is to develop a sensor system, based on piezoelectric polymers, that is capable identifying the equivalent of stroke affected brain regions beneath a human skull. The project does not involve human or animal experimentation, and will use simulated brain analogues.

Imaging Physics Dr Alexis Bishop

Planets around evolved stars

The results from stellar evolution calculations are an essential tool for studies of extra-solar planets. While most extra-solar planets are found around solar-type main sequence stars, planets are found around cooler evolved red giant stars. Observational studies suggest these planet-hosting evolved stars may be metal poor, in contrast to the main-sequence stars with planets, which tend to be metal rich (Maldonado et al. 2013). When a star exhausts it's supply of hydrogen the outer layers expand and the star becomes a red giant. Will it expand enough to swallow the planets that orbit it? The answer to that question depends on the initial mass and composition of the star, and masses and orbital characteristics of the planets (e.g., Villaver et al. 2014).

In this project you will use theoretical models of stars from the main sequence to the tip of the asymptotic giant branch to study the impact of stellar evolution on the orbits of planets. You will start with predicting the future of our Sun and Earth (e.g., Schroeder & Connon Smith 2008) and then expand the calculations to include other mass planets, and stars of different mass and composition.


[1] Maldonado, J. et al. 2013, Astronomy & Astrophysics, 554, A84

[2] Villaver, E. et al. 2014, The Astrophysical Journal, 794, p3

[3] Schroeder, K.-P. & Connon Smith, R. 2008, Monthly Notices of the Royal Astronomical Society, Volume 386, Pages 155

Astronomy & Astrophysics Associate Professor Amanda Karakas

Precise atomic-scale structure determination in thick nanostructures

Knowing where atoms are and how they are bonded is vital to understand the properties and performance of advanced materials. Among various atomic-scale characterisation methods, transmission electron microscopy has proven highly successful for precise structure determination. Breakthrough advances in fast-readout pixel detectors are enabling structure determination at unprecedented resolution. Despite these new tools, reliable structure determination remains restricted to ultrathin (a few nanometers thick) materials – a small subset of all materials of technological interest – as existing methods fail in thicker nanostructures due to multiple scattering of the probe electrons. Overcoming this limitation is the focus of much research [1-3].

This computational project could take several directions, including:

  • Extending existing thin-object reconstruction strategies by developing iterative algorithms to correct for multiple scattering.
  • Comparing phase retrieval strategies for determining the so-called scattering matrix with as few measurements as possible.
  • Developing methods to characterise instrument aberrations from the data itself.
  • Generalising methods to handle non-periodic structures.


[1] D. Ren, M. Chen, L. Waller & C. Ophus, ArXiv eprints (2018), arXiv:1807.03886

[2] H.G. Brown et al., Physical Review Letters 121 (2018) 266102

F. Wang, R.S. Pennington & C.T. Koch, Physical Review Letters 117 (2016) 015501

Imaging Physics,
Condensed Matter Physics,
Theoretical & Computational Physics
Dr Scott Findlay

Probing neutron stars via thermonuclear bursts

Studies of thermonuclear (X-ray) bursts in accreting neutron stars have historically relied on short observations of individual sources, resulting in (usually) a handful of bursts. Another approach is to gather large numbers of bursts from multiple sources and telescopes, and analyse the resulting combined sample to better understand the physics of this phenomena. Such an effort is currently underway at Monash with the Multi-INstrument Burst ARchive (MINBAR), which presently consists of approximately 2200 bursts from NASA's Rossi X-ray Timing Explorer satellite as well as the defunct Dutch/Italian mission BeppoSAX. The principal efforts at present are to add bursts in public data observed by the JEM-X camera onboard ESA's INTEGRAL satellite, likely adding another 2000 events and with new observations continually being added. The catalog, once complete, will prove a vital resource for studies of thermonuclear bursts and will be released to the public.

This project will involve analysis of burst data, cross calibration, and verification for addition to the burst sample. It is expected that the student will also work on burst data from newly-discovered transient neutron stars through the course of the project, and collaborate on papers resulting from this work.

This project will primarily involve analysis of reduced data from the various X-ray satellites with IDL. Opportunities exist for work with project partners at SRON (Netherlands) and DTU Space (Denmark).

Astronomy & Astrophysics Associate Professor Duncan Galloway

Prospects for atomic-resolution magnetic field imaging

The development of aberration-correctors in the early 2000s has enabled electron microscopes to routinely “image” materials at atomic resolution. These images primarily probe the electrostatic potential of the atoms. Electron microscopes are also able to probe magnetic fields in materials [1], however this has not yet been achieved at atomic resolution. The limitation that the magnetic field of the electron microscope lens changed the magnetic structure of the sample of interest has recently been overcome via a new lens design [2]. However, the more fundamental challenge is that the interaction between the electrons in the probe beam and the sample magnetic field is orders of magnitude smaller than that with the sample electric field, making magnetic effects very hard to detect. Nevertheless, progress is being made [3].

This computational project will explore ways on incorporating magnetic field effects in electron microscope imaging calculations, and strategies (like beam shape and detector geometry) which might help enable atomic-resolution magnetic field imaging.


[1] J.N. Chapman and M. R. Scheinfein, Transmission electron microscopies of magnetic microstructures, Journal of Magnetism and Magnetic Materials 200 (1999) 729

[2] N. Shibata et al., Atomic resolution electron microscopy in a magnetic field free environment, Nature Communications 10 (2019) 2308

[3] K. Nguyen et al., Multislice Electron Scattering Simulations for Angstrom-Scale Magnetic Measurements with 4D-STEM, Microscopy & Microanalysis 2020 conference proceedings

Imaging Physics,
Condensed Matter Physics,
Theoretical & Computational Physics
Dr Scott Findlay

Quantitative Electron Tomography at the Nanoscale

Electron tomography is a 3D characterisation technique that can be performed in a scanning transmission electron microscope (STEM) [1,2]. It is capable of sub-nanometre resolution, and in some cases can even resolve individual atoms in 3D [3]. However, its accuracy is primarily geometric - it determines the shape of the object with high resolution but the correlation between the reconstructed intensity in an individual voxel (volume pixel) and the physical properties of the object (density, atomic number, etc.) is poor.

This project seeks to improve the correlation between voxel intensity and atomic number / density of a sample based on recent work that models the physics of electron scattering to put the recorded STEM intensities on an absolute scale [4]. This will primarily be investigated via numerical simulation, though options for combining simulation and experimental data from simple, standard specimens may also be explored. This project involves computation - learning to use programs for generation of crystal structures, multislice image simulation and tomographic reconstruction - and potentially experimental data analysis on data obtained at the Monash Centre for Electron Microscopy. The student may be involved in (but not directly running) sample preparation by focused ion beam milling and electron tomography experiments.


[1] M. Weyland, Electron Tomography of Catalysts, Topics in Catalysis volume 21, issue 4, 2002.

[2] M. Weyland et. al., Three-Dimensional Structural and Compositional Characterisation of Nanoscale Materials by Alternative Modes of Electron Tomography, Scripa Materialia 55 (1) 2006.

[3] S. Van Aert et. al., Three-dimensional atomic imaging of crystalline nanoparticles, Nature volume 470, issue 7334, 2011.

[4] James M. LeBeau, Scott D. Findlay, Leslie J. Allen, and Susanne Stemmer, Quantitative Atomic Resolution Scanning Transmission Electron Microscopy, Phys. Rev. Lett. volume 100, issue 20, 2008

Imaging Physics,
Condensed Matter Physics,
Theoretical & Computational Physics
Dr Matthew Weyland,
Dr Scott Findlay

Quantum engines in many-body systems

In recent years, many concepts belonging to thermodynamics have been translated to quantum systems. While the description of such systems is often highly abstract, this project will explore some of these ideas in the context of physically realisable many-body quantum systems.

Quantum Gases,
Condensed Matter Physics,
Theoretical & Computational Physics
Associate Professor Meera Parish,
Dr Jesper Levinsen

Quantum hearing: Using cold atoms to sense weak signals in noise

Hearing is amazing – your ears and brain can pick our your name dropped in conversation against a noisy background many times louder. Recorded sound needs hundreds of kilobits per second, yet your brain deals with the datastream in real time. What does this have to do with quantum mechanics? In this project, you will create a ‘quantum hearing cell’ made of ultracold atoms which senses audio-frequency magnetic fields with ‘hearing-like’ properties of frequency selectivity, and even with phase selectivity. The ultimate goal is to build a 'quantum cochlea', inspired by the mammalian auditory system - an array of quantum sensors each tuned to a different frequency which will sense complex signals efficiently and at the quantum noise limit.

Quantum Gases Dr Lincoln Turner

Quantum process tomography of an evolving spinor condensate

Quantum process tomography lets you work out what Hamiltonian a quantum system is evolving under, by feeding different states into the process and measuring what comes out. But what if you have only one quantum state, for example a Bose-Einstein condensate you don't want to destroy in a projective measurement? In a previous Honours project, Michael Kewming showed that quantum state tomography could be done on BECs - many times over without destroying the BEC. In this project you'll extend this to quantum process tomography, using many successive measurements on an evolving BEC to measure its mean-field spinor Hamiltonian.

Quantum Gases Dr Lincoln Turner

r-band as a star formation rate indicator

For this project, you will calibrate r-band as a star formation rate indicator, which can then be used to measure the star formation rates of galaxies across the whole sky. Galaxies grow in stellar mass via galaxy mergers and star formation, with the latter process dominating the growth of low mass galaxies. Accurate measurements of star formation rates are thus critical for understanding how galaxies grow over cosmic time. Unfortunately measuring star formation rates in low mass galaxies is challenging, with local dwarf galaxies often being undetected (or lacking data) in ultraviolet, mid-infrared and radio continuum bands. However, the H-alpha emission line is present in the optical r-band, and there will soon be r-band coverage of the whole sky from SDSS, Panstarrs and Skymapper. If one can effectively use i-band and z-band to subtract the stellar continuum, r-band photometry can be used to measure star formation rates for local galaxies across the entire sky.


Brown et al., 2014, ApJS, 212, 18 (arXiv: 1312.3029)

Brown et al., 2017, ApJ, 847, 145 (arxiv: 1709.00183)

Moustakas and Kennicutt., 2006, ApJS, 164, 81

Astronomy & Astrophysics Associate Professor Michael Brown

Rapid x-ray phase and dark field imaging

The honours project will involve measuring and quantifying these 'phase-contrast' and ‘dark-field’ signals captured with these methods, specifically when resolved over time. There are opportunities for computational modelling to elucidate the imaging process, experimental implementation on various x-ray sources and numerical analysis of the resulting images.  Depending on the preferences of the student, the project could also look at incorporating new algorithms [5] into the image analysis code.

X-ray imaging has become an essential tool in the medical field, but conventional absorption methods are still limited in their ability to differentiate between different types of soft tissue. Various methods of phase-contrast x-ray imaging enable visualisation of soft tissue by taking advantage of the changes in the direction of x-ray propagation [1].    In addition, a ‘dark field’ signal can be collected that maps scattering by structures that are too small to resolve directly, like the air sacs in the lungs or cracks in manufactured parts [1].  These image modalities are already being applied in biomedical research [2].    However, many of these methods require multiple images to reconstruct the phase or dark-field images, which is an obstacle when imaging breathing, moving subjects or where the total imaging time should not be too long (e.g. airport security).    Therefore, we are developing methods that either work with only a single exposure [3] or that carefully time image capture to match sample/patient movement [4].


[1] Marco Endrizzi, “Phase contrast x-ray imaging”, Nuclear Inst. And Methods in Physics Research A (2017).

[2] PhysicsWorld - “Making the invisible visible”

[3] Kaye Morgan, Timothy Petersen, Martin Donnelley, Nigel Farrow, David Parsons and David Paganin, “Capturing and visualizing transient x-ray wavefront topological features by single-grid phase imaging”, Opt. Express 24 (2016).

[4] R. Gradl et al. – Dynamic in vivo chest x-ray dark-field imaging in mice. IEEE transactions on medical imaging, 38(2), pp.649-656 -

[5] K. S. Morgan and D. M. Paganin, 2019. - Applying the Fokker–Planck equation to grating-based x-ray phase and dark-field imaging. Scientific reports, 9(1), pp.1-14. -

Imaging Physics Dr Kaye Morgan

Rotation in Massive stars with Varying Spin Direction

With LIGO and its cousins and successors, it has now become possible to detect the gravitational waves from merging close binary star systems. Indeed, the the detections and analyses have become so sophisticated that they place constrains on the rotation axes of the merging stars. What is a lot less well known, however, is how we may get there, in particular, how the rotation evolves inside these massive stars that make the black holes or neutron stars that merge.  Simple one-dimensional models do exist that follow the rotation from star formation (pre-main sequence) to stellar death (core collapse), even including magnetic fields [Ref 1], however, they all assume that the rotation axis of the star remains fixed and is the same for all layers.

This, however, may well be a crude oversimplification.

As stars form inside a turbulent molecular cloud, they may accrete material with varying angular momentum direction.  For low-mass star such as the sun, they will be fully convective in their infancy, likely aligning the entire spin.  For the sun we find that the orbital plane in which the planets move is misaligned with the spin of the sun by some 7 degrees, suggesting notable misaligned of the last accretion phase that made the planets with the average of the earlier accretion that made the sun.

For massive stars that die as neutron stars or black holes, accretion is still continuing for a major fraction of their lifetime, i.e.,  while the star is already evolving and is no longer fully convective.  With variation of angular momentum direction of accreted material continuing, the star may build up layers rotating about different axes from the core to the surface of the star.

The goal of this project is to understand the relative motion and shear between these layers.  This can include potential instabilities that lead to transport of angular momentum and composition.  The project can also involve understanding hydrodynamic fluid instabilities and implementing some of the ideas into a code, in collaboration with the supervisors, and performing simulations of the evolution of such stars until core collapse.  The results will be an original new contribution helping to shed new light on interpreting gravitational wave signals.


[1] Heger, A.; Woosley, S. E.; Spruit, H. C.: "Presupernova Evolution of Differentially Rotating Massive Stars Including Magnetic Fields", The Astrophysical Journal, Volume 626, Issue 1, pp. 350-363, 2005.

Astronomy & Astrophysics Professor Alexander Heger,
Dr Bernhard Mueller,
Dr Rosemary Mardling

Searching for Beyond Standard Model physics with the COMET detector

The Standard Model of Particle Physics has been incredibly successful at describing every fundamental particle interaction which we have measured over the last decades. Interactions which are either forbidden by the Standard Model, or extremely rare offer an opportunity to look for effects which result from new physics contributions not described by the Standard Model.

The COMET experiment currently being constructed in Japan will search for the Charged Lepton Flavour Violating (CLFV) decay of muons to electrons.  The Standard Model calculation for this decay predicts an extremely small rate while many Beyond Standard Model (BSM) physics contributions would potentially give much larger rates.  If evidence of this reaction is seen at COMET it would point to the existence of new physics previously undetected.

The project will involve working with Simulations of the COMET detector, and working to help prepare for initial running of the detector due to take place in the next few years. Any students who would like to take part should have some experience of programming, with experience of C++ being particularly useful.

If you would like to discuss this project please contact Jordan.Nash@monash.edu

Particle Physics Professor Jordan Nash

Shattering insights towards the atomic structure of glasses

The formation and atomic structure of glasses remains a long-standing important and unsolved problem in condensed matter physics. Despite continued international efforts, there are many intriguing scientific questions which remain unanswered. For example, how can a brittle solid maintain short range order yet still possess the structure of a liquid, supposedly devoid of long range order? What is the atomic structure of an archetypal vitrified monatomic solid, such as pure amorphous silicon or diamond like carbon? Do the atoms form continuous random networks or, as recently and hotly debated in Science [1, 2, 3], are there nano-scopic 'para-crystals' inter-dispersed within a structurally-frustrated meta-stable ensemble? For low density carbonaceous solids, do Fullerenes, such as interwoven, buckled, graphene sheets and nanotubes, provide an adequate description of the medium range order [4, 5]?

Using high-resolution transmission electron microscopes (TEMs), this project will acquire experimental data to address several of these fundamental questions. There are also opportunities to implement modelling techniques to interrogate the structure of such glasses, ranging from Monte Carlo integration techniques to the advanced processing of scanning electron nano-diffraction patterns [6]. Theoretically inclined students could also develop associated Hybrid Reverse Monte Carlo source code [7, 8], to increase the number of many-body inter-atomic potentials for describing bonding configurations in multi-component glasses.

Modern wonder materials like metallic glasses have interesting properties, such as substantial hardness, and can undergo super-plastic deformation [9]. The glass forming abilities of bulk metallic glasses are sensitively tied to composition and generally a multitude of elements are required to cause structural arrest in rapid thermal quenching from the liquid state. However, several binary and ternary alloys have been identified as good glass formers. Such metallic glasses are being synthesized by collaborators at CSIRO and are available for this project. Several pertinent questions concerning these alloys need to be addressed. For example, on the atomic scale, are these glasses partially crystallized? Can the pair correlation functions be reliably measured and how do these correlate with the alloy properties? Experimental students would be trained to prepare ultra-thin metallic glass foils and will analyze high quality experimental data from TEMs at the Monash Centre for Electron Microscopy.


[1] "The local structure of amorphous silicon", M. M. J. Treacy and K. B. Borisenko, Science 335, 950 (2012).

[2] Comment on "The local structure of amorphous silicon", S. Roorda and L. J. Lewis, Science 338, 1539 (2012).

[3] Response to Comment on "The local structure of amorphous silicon", M. M. J. Treacy and K. B. Borisenko, Science 338, 1539(2012).

[4] "High-resolution transmission electron microscopy study of a cross-linked fullerene-related multilayer graphitic material", L. N. Bourgeois and L. A. Bursil, Phil. Mag. A, 79, 1155 (1999).

[5] "Curved-surface atomic modelling of nanoporous carbon", T. C. Petersen, I. K. Snook, I. Yarovsky, D. G. McCulloch, and B. O'Malley, J. Phys. Chem. C; 111, 802 (2007).

[6] "Systematic mapping of icosahedral short-range order in a melt-spun Zr36Cu64 metallic glass", A. C. Y. Liu, M. J. Neish, G. Stokol, G. A. Buckley, L. A. Smillie, M. D. de Jonge , R. T. Ott, M. J. Kramer and L. Bourgeois, Phys. Rev. Lett. 110, 1539 (2012).

[7] "Structural analysis of carbonaceous solids, using an adapted Reverse Monte Carlo algorithm", T. Petersen, I. Yarovsky, I. Snook, D. G. McCulloch, G. Opletal, Carbon, 41, 2403-2411 (2003).

[8] "HRMC_2.0: Hybrid Reverse Monte Carlo method with silicon, carbon and germanium potentials", G. Opletal, T. C. Petersen, I. K. Snook and S.P. Russo, Computer Physics Communications 184, 1946 (2013).

[9] "Superplastic deformation of Zr65Al10Ni10Cu15 metallic glass", Y. Kawamura, T. Shibata, A. Inoue and T. Masumoto, Script. Mat. 37, 431 (1997).

Condensed Matter Physics Dr Timothy Petersen

Spectroscopy and the composition of stars in globular clusters

Globular clusters are the oldest and most populous stellar aggregates in existence. Recent studies have shown that the stars in globular clusters show abundance patterns that are unique to the clusters. We do not know why they are not seen in the Galaxy, but only within the globular clusters. They may even be the remnants of collisions between dwarf Galaxies and our Milky Way. A fuller understanding requires us to determine the abundances of many stars in many clusters and to compare with theoretical models so we can see what stars produced the existing patterns.

We will source original data form the world's largest telescopes and then analyse this to determine the abundances of key species in globular cluster stars: perhaps Li, C, N, O, Mg, Al, Fe as well as the heavy elements made by neutron capture, such as Sr, Y, Zr, Ba, La. Stellar models that can produce these species will be compared with the abundances we measure.

This project will involve travel to the Australian Astronomical Observatory (in Sydney) to visit and work with Dr de Silva. There is also the opportunity to visit the 4m Anglo-Australian Telescope in Coonabarabran, NSW.

Astronomy & Astrophysics Professor John Lattanzio,
Dr Simon Campbell

SPH with numerical relativity

In this project we will attempt to couple our existing smoothed particle hydrodynamics (SPH) code for simulating flows around black holes to a backend that allows for dynamical evolution of the background spacetime. Successful completion of the project will enable state of the art calculations of neutron star mergers in full general relativity.

Astronomy & Astrophysics Professor Daniel PriceDr Paul Lasky

Split-Field Spectral Computed Tomography

X-ray computed tomography (CT) is a method to non-destructively image the internal structures of a three dimensional object. However, conventional CT suffers from the inability to distinguish different materials. It has been shown that this can be overcome by combining data sets taken at two or more different X-ray energies, which is often called dual-energy, or spectral CT, respectively [1]. Common implementations of dual-energy CT make use of energy resolving detectors, or a change of the X-ray illumination between two acquisitions [2, 3].

The goal of this project is to design and implement a method to perform dual-energy CT that can be readily implemented into existing imaging systems. We plan to combine X-ray filters and exploit intrinsic symmetries present in X-ray imaging to simultaneously acquire CT data at different X-ray energies. This would circumvent the need for an energy resolving detector or multiple sequential acquisitions and their respective drawbacks.

Experiments will be conducted both at the Australian Synchrotron, and Monash University. Data analysis includes image processing, tomographic reconstruction, and implementation of algorithms for elemental separation. Depending on the progress, the possibility to work towards combining these methods with phase-contrast X-ray imaging exists.


[1] Robert E. Alvarez and Albert Macovski , “Energy-selective reconstructions in X-ray computerised tomography”, Phys. Med. Biol., volume 21, 733 (1976)

[2] M. Paziresh, A. M. Kingston, S. J. Latham, W. K. Fullagar, and G. M. Myers, “Tomography of atomic number and density of materials using dual-energy imaging and the Alvarez and Macovski attenuation model”, Journal of Applied Physics, volume 119, 214901 (2016)

[3] S. Ehn, T. Sellerer, K. Mechlem, A. Fehringer, M. Epple, J. Herzen, F. Pfeiffer and P. B. Noël, “Basis material decomposition in spectral CT using a semi-empirical, polychromatic adaption of the Beer-Lambert model”, Phys. Med. Biol., volume 62, N1–N17 (2017)

Imaging Physics Dr Florian Schaff,
Dr Kaye Morgan,
Associate Professor Marcus Kitchen

Statistical mechanics of random Graphs and complex networks

Many systems in nature can be described in terms of complex networks. Non-trivial examples include genetic networks, ecological networks and spin networks. This project will apply the principles of statistical mechanics to explore the organising principles and dynamics of random graphs and complex networks. Field theoretic techniques will be used to investigate an ensemble of random graphs, including networks that exhibit a Bose-Einstein phase transition.


[1] R. Albert, A-L Barabasi, "Statistical mechanics of complex networks", Reviews of Modern Physics, Volume 74, Issue 47 (2002).

Theoretical & Computational Physics Professor Michael Morgan

Stellar population synthesis

Stars are born in clusters. These are very valuable tools for learning about stellar processes, because they provide us with a large number of stars, all born at the same time, but with different masses. Hence we can do statistical studies to understand what is happening to the stars. However, detailed stellar models take a lot of computer time. Yet it is possible to make some approximations that are very accurate, informed by the results of detailed models, which enable us to produce a statistical model of a cluster of stars. This is called "Population Synthesis". One application of this is to investigate the evolution of red-giants that become carbon stars. Does the predicted distribution match what we see in real clusters?

Skills required: Some interest in programming is needed. That could be fortran or another high level language, or even MATLAB or something similar. Some astronomy would be an advantage, especially second year units. But is not essential.

Astronomy & Astrophysics Professor John Lattanzio,
Dr Simon Campbell

Study of Flavour Anomalies

An important component of particle physics research is the study of rare processes in 'flavour physics'. In current experiments this typically refers to decays of bottom or charm mesons that have very small branching fractions. Recent experimental studies of these decays have produced a number of 'anomalies', or disagreements with the standard model expectations.

In this project we will study these anomalies from the theoretical perspective, looking for common threads that can lead to global explanations in terms of new physics. When good explanations are found, they also produce predictions for upcoming experiments that can rule the out (or, with much luck, confirm them).

Particle Physics Professor German Valencia

Strings in Quantum Chromodynamics

In this project, we will consider the physics of “hadronisation” - the process by which high-energy quarks and gluons turn into hadrons. This is intimately related to a fundamentally unsolved question in theoretical physics - the problem of confinement. (There is even a $1M prize for finding a solution to it.) Today, the most successful and widely applied physical model of the process of hadronisation is based on strings. Essentially, a high-mass string, with a single quark and antiquark as its endpoints, breaks into a series of smaller string pieces - hadrons - via a series of tunnelling events. The model makes several intrinsic assumptions however, which are now beginning to be challenged by new data from the Large Hadron Collider. Motivated by this data, we will consider simple alternative formulations of the string model, and compare these with data. This project is well suited for students with an interest in theoretical physics (note, however, that the strings we consider are not superstrings; there is no connection between this project and quantum gravity), computer physics (the string model is implemented as a C++ code), and physics at the Large Hadron Collider.

Particle Physics Associate Professor Peter Skands

Supernova Explosions and General Relativity

Core-collapse supernovae mark the death of massive stars: In an evolved star that has gone through the various burning stages, its iron core eventually collapses, leaving behind a neutron star, while the envelope is expelled in a violent and very bright explosion [1]. These explosions are fascinating laboratories for matter under extreme conditions and cosmic furnaces that make many of the chemical elements that are the building block of planets like ours. Supernovae are also promising sources of neutrinos and gravitational waves.

As the engine powering the explosion is hidden deep inside the stellar core, we need numerical simulations to understand the supernova mechanism. Simulation codes need to include include a variety of physical ingredients such as multi-dimensional fluid flow [2], general relativistic effects, and radiation transport.

In this project, we will explore the role of general relativistic effects in a more controlled manner than hitherto possible. Previous comparisons of relativistic and Newtonian models [3,4] have been plagued by differences in grid resolution and numerical methods, whereas this project will use a single code to eliminate these confounding factors. The project will entail one- and two-dimensional simulations, some of whom will be performed on national supercomputers.


[1] Janka 2012, Annual Review of Nuclear and Particle Science 62, 407

[2] Mueller 2016, Publications of the Astronomical Society of Australia 33, e48

[3] Mueller, Janka & Marek 2012, The Astrophysical Journal 756, 84

[4] Liebendoerfer et al. 2005, The Astrophysical Journal 620, 840

Astronomy & Astrophysics Dr Bernhard Mueller,
Professor Alexander Heger

Supernovae Making Neutron Stars or Black Holes?

When a massive star reaches the end if its life, the core collapses into a neutron star or, possibly, a black hole. In many cases, at first a shock is launched moving outward, ejecting the outer layers of the star. But there may not be enough energy to eject the entire core, or there can be hydrodynamic interactions in the envelope that push some of the matter onto the central object. How much of the material falls back will determine the final mass of the compact remnant that is left behind. If the mass exceeds the maximum mass for a neutron star, it will collapse to a black hole.

For this project you will use an analytic model for supernova explosions and their energies to simulate the explosion of these stars. You will then use a one-dimensional hydrodynamic code modified for proper inner boundary conditions, to simulate the dynamics of the explosion and how much mass is ejected or fall back. This will allow you to estimate the remnant mass (some of the rest mass is carried away by neutrinos). Using a range of supernova progenitor models, you can make perditions about the distribution of neutron star and black hole masses.


[1] W. Zhang, S. E. Woosley, and A. Heger, "Fallback and Black Hole Production in Massive Stars ", The Astrophysical Journal, Volume 679, Number 1 (2008)

[2] H-T. Janka, "Explosion Mechanisms of Core-Collapse Supernovae ", Annual Review of Nuclear and Particle Science, Volume 62, pages 407-451 (2012).

[3] O. Pejcha and T. A. Thompson, "The landscape of the neutrino mechanism of core-collapse supernovae: neutron star and black hole mass functions, explosion energies, and nickel yields ", The Astrophysical Journal, Volume 801, Number 2 (2015).

[4] S. E. Woosley, A. Heger, and T. A. Weaver, "The evolution and explosion of massive stars ", Reviews of Modern Physics, Volume 74, 1015 (2002).

[5] A. Heger, C. L. Fryer, S. E. Woosley, N. Langer, and D. H. Hartmann, "How Massive Single Stars End Their Life ", The Astrophysical Journal, Volume 591, Number 1 (2003).

Astronomy & Astrophysics Professor Alexander Heger

Supersymmetric dark matter

When interpreted within the standard (ΛCDM) cosmological framework astrophysical observations indicate that some 85 percent of the matter in the Universe is non-luminous (dark). Supersymmetry offers a natural explanation for this dark matter in the form of the lightest supersymmetric particle.

While the minimal supersymmetric extension of the standard particle model is constrained into a fine-tuned theoretical region by experiments, extending the Higgs (electroweak symmetry breaking) sector of these models can remove this problem.

This project examines whether we can obtain an amount of dark matter consistent with observations within a particular realization of the next-to-minimal supersymmetric standard model while staying in the natural part of the parameter space and remaining consistent with various collider, astrophysical and low energy measurements.


[1] H. Baer, C. Balazs, "χ2 analysis of the minimal supergravity model including WMAP, g(mu)-2 and b → gamma constraints", arXiv:hep-ph/0303114

[2] C. Balazs, M. S. Carena, A. Menon, D.E. Morrissey, C. E. M. Wagner, "The Supersymmetric origin of matter", Physical Review D, Volume 71, 075002 (2005).

[3] C. Balazs, D. Carter, "Discovery potential of the next-to-minimal supergravity motivated model", Physical Review D, Volume 78, 055001 (2008).

[4] C. Balazs, D. Carter, "Likelihood analysis of the next-to-minimal supergravity motivated model", AIP Conference Proceedings (2009).

Particle Physics Professor Csaba Balazs

Supersymmetric origin of matter

Supersymmetry has the potential to explain the origin of all, baryonic (visible) and non-luminous (dark), matter in the Universe. While dark matter may be the lightest supersymmetric particle, a baryon-antibaryon asymmetry can be generated by electroweak baryogenesis in the (next-to-)minimal supersymmetric extension of the standard particle model.

Electroweak baryogenesis is typically driven by charged superpartners of the standard gauge bosons (gauginos). While in the minimal models the matter content of the Universe is successfully reproduced, these scenarios face stringent constraints from experiments measuring the electric dipole moments of electrons.

In this project, we explore the possibility that electroweak baryogenesis can be driven by neutral gauginos, gauge singlet scalars or by non-standard gauge bosons. In such models the electric dipole moment constraints would not apply, but the question whether the dark matter content is consistent with measurements remains to be examined.


[1] C. Balazs, M. S. Carena, A. Menon, D.E. Morrissey, C.E.M. Wagner, The Supersymmetric origin of matter, arXiv:hep-ph/0412264.

[2] C. Balazs, M. S. Carena, A. Freitas, C.E.M. Wagner, Phenomenology of the nMSSM from colliders to cosmology, arXiv:0705.0431.

[3] Y. Li, S. Profumo, M. Ramsey-Musolf, Bino-driven Electroweak Baryogenesis with highly suppressed Electric Dipole Moments, arXiv:0811.

Particle Physics,
Theoretical & Computational Physics
Professor Csaba Balazs

Symmetry of local structures in glasses

In condensed matter physics, the structure of a material is integral to its nature. For example, at the liquid-to-crystal phase transition, symmetry is broken and translational symmetry arises. The new phase is rigid and this property is due to lattice symmetry; the force exerted on any particle in the array is exactly cancelled by neighbours.
Glasses don’t fit this description; they are solids with liquid structure. Why glasses are solid and how they deform via brittle fracture are open questions. The lack of knowledge and understanding of the structure of glasses is a major road-block for glass science and technology.
A series of new and measureable parameters that are sensitive to the symmetry of local atomic arrangements in glasses has recently been demonstrated by Monash University researchers [1,2,3]. At the same time, the average degree of symmetry in local atomic arrangements has been proposed as a key parameter in understanding the rigidity of glasses [4]. This project will test if the average centro-symmetry of local structures does correlate to the hardness of glasses. The project will involve electron diffraction measurements on a next-generation scanning-transmission electron microscope (UltraTEM – installation in the Monash Centre for Electron Microscopy scheduled for late 2019). Experimental results will be matched to simulations from atomic models.
The project would suit a student interested in experimental and computational materials physics and developing new imaging methods and data analysis tools.


[1] A. C. Y. Liu, M. J. Neish, G. Stokol, G. A. Buckley, L. A. Smillie, M. D. de Jonge, R. T. Ott, M. J. Kramer, and L. Bourgeois, Phys. Rev. Lett. 110, 205505 (2013)

[2] A. C. Y. Liu, R. F. Tabor, L. Bourgeois, M. D. de Jonge, S. T. Mudie, and T. C. Petersen, Phys. Rev. Lett., 116, 205501 (2016)

[3] A. C. Y. Liu, R. F. Tabor, M. D. de Jonge, S. T. Mudie, and T. C. Petersen, Proc. Nat. Acad. Sci., 114, 10344–10349 (2017)

[4] M. Schlegel, J. Brujic, E. M. Terentjev, and A. Zaccone, Sci. Rep. 6, 18724 (2016)

Imaging Physics,
Condensed Matter Physics,
Theoretical & Computational Physics
Dr Amelia Liu,
Dr Timothy Petersen,
Dr Scott Findlay

The aftermath of merging neutron stars

When two neutron stars collide they emit large quantities of energetic electromagnetic radiation and gravitational waves. To date, we have observed the gamma-ray and X-ray emission of these catastrophic collision, but have not yet observed their gravitational wave signal. Regardless, what happens following the merger is heavily debated, and depends on complicated details of the way matter behaves in these hot, dense environments. Whether the post-merger remnant is a black hole, an unstable neutron star that eventually collapses into a black hole, or an eternally stable neutron star, is uncertain. In this project, we will use gamma- and X-ray observations, as well as state-of-the-art neutron star models to understand electromagnetic and gravitational-wave observations that are the smoking gun for determining whether a black hole or a neutron star is born during these mergers.