PhD projects

PhD projects

quantum_splash_header

The Quantum Science and Technology focused PhD Programme

Students can be trained to be high achieving researchers in Quantum Science and Technology via the MQ Doctor of Philosophy (PhD). These students work with leading theorists and experimentalists in quantum science and technology, to develop deep understanding how the fundamental ideas of quantum physics can be used to build the most advanced quantum sensors in the worlds and to advance our understanding of the Quantum Sciences. PhD researchers will develop considerable expertise in data analysis, modelling, computer visualilation, optical manipulations and the most advanced metrological schemes during their studies. The 3 year PhD program enables the student to progress to become an independent researcher. At completion of their studies they will have acquired problem-solving capabilities, which will allow them to undertake and innovate state-of-the-art original research. They will also be able to communicate the relevance, significance and context of their work with their peers.  Students graduating from the PhD programme in quantum science often choose a diverse range of careers spanning biomedical research through to topological quantum circuits and some have continued to postdoctoral research in Karlsruhe Institute of Technology and the Singapore University of Technology and Design and Ulm University.

A wide range of potential PhD topics are on offer. Students interested in particular projects are strongly encouraged to contact the relevant supervisor(s).

Why study Quantum Science and Technology at Macquarie University

Why undertake your higher degree focused in Quantum Science and Technology at Macquarie University? We have smart people, excellent infrastructure and facilities and a supportive environment focused on building your skills for enquiry, research and innovation.

Intellectual environment

Our alumni enjoy doing researching and learning with one of the most cohesive, extensive and awarded quantum scientists in Australia. Our research team in the Quantum Sciences includes eight continuing academics working in areas ranging from: Quantum Photonics to Topological Quantum Computation. Our research team has been continuously funded by Macquarie University during the last seven years through the Macquarie Research Centre in Quantum Science and Technology (QSciTech). Our academic researchers publish regularly in top journals such as Science, Nature Physics and Nature Photonics and our research is supported by the Australian Research Council through the Centre of Excellence program (CoE for Engineered Quantum Systems, EQuS, CoE for Ultra-High Bandwidth Optical Devices CUDOS),  and have received multiple awards, including two Future Fellowships. The main thrive of our Centre is to build the best quantum sensors in the world, which would complete transform the technologies in the near future. We are working in quantum enhanced magnetic sensors, gravimeters and gyroscopes, which have attracted the interest of the companies which are involved in our Advisory Board: Microsoft Research, Lockheed Martin Inc. and QxBranch. We have also designed some of the most accurate quantum metrology schemes and are continuously developing new algorithms for quantum computing. The excellence of our research has been acknowledged by the Australian Government as we have been ranked three times consecutively as ERA 5, which recognises that our research activities are “Well above world standard”

Training environment

The breath of our research activities and our international links, make Macquarie an ideal environment to get the most out of your post-graduate degrees. Our Centre is regularly visited by the top scientists in the world including, for example, Nobel Laureates Profs. Tony Legett and Bill Phillips, or Prof. Sir Michael Berry and Prof. Sir Peter Knight. Our students learn Quantum Physics from the best!

Access to facilities

Our students have access to the most advanced experimental facilities in the fields of quantum optics:

More about HDR with MQ Quantum Science and Technology

Outreach and Education

The high degree research students within our Research Centre find innumerable opportunities to contribute to Outreach Activities both within the Centre and in the wider context of the Department. Some examples are the Indigenous Science Day @ Redfern or the Science Experience @ MQ.

MRES: Masters by Research

We offer Masters by Research degrees focusing on Quantum Science and Technology related research topics through the Macquarie University MRES degree. This two year degree involves eight units of coursework training and then a full year research project. For a flavour of current/past MRES projects in Quantum click here. Students accepted to this degree receive an automatic scholarship which increments from Yr1 to Yr2. For more information on the MRES degree click here.

Eligibility

The competition is high to obtain a Macquarie University PhD scholarship and to get some idea regarding the academic quality and eligibility for these please see our scholarship eligibility requirements. Proficiency in English is required by all HDR candidates and the standards set by Macquarie University are:

  • TOEFL (computer-based): Overall of 237 with minimum 19 in Listening, 19 in Reading, 25 in Structure/Writing and TWE of 5.0; OR
  • TOEFL (paper-based): Overall of 580 with 53 in Listening, 52 in Reading, 59 in Structure/Written Expression and TWE of 5.0; OR
  • iBT (internet-based TOEFL): Overall score of 92 with 23 in Speaking, 18 in Listening, 17 in Reading and 22 in Writing; OR IELTS (academic version): Overall 6.5 with minimum of 6.0 in each band

The University rigorously applies these.

How to Apply

To apply for either our PhD or MRES degree programme you need to complete an EXPRESSION OF INTEREST application form online. For this you will be asked to select your preferred research project from the list of offered PhD projects, your CV, and list of two potential Referees who you agree we can contact, and a brief statement regarding your short-term and long-term motivation for undertaking the degree programme.

This information allows us to judge your capability with other students applying so we can select those best suited to advance to full admission through the University scholarship programme.

Once selected you will be paired with a potential Supervisor who will then invite you to an interview. These interviews help potential students get a better feel for what the Degree Programme and research will be like. These interviews will be via Skype, phone or in-person and will take place at most one month after the Expression of Interest deadline.

Once you have passed the interview and the potential Supervisor agrees to supervise your PhD studies you need to prepare a formal application. This application will be to Macquarie University and will enable you to apply to all types of scholarships that you will be eligible for. You will need some referees to also fill out pre-set referee application forms and these are sent separately to the Macquarie University HDR office. Applicants are strongly advised to prepare their applications as soon as possible after finding a supervisor. Copies of some documents must be certified (by the relevant authorities) as part of the formal application.

PhD projects

The projects below are available for possible PhD projects. We encourage you to read them, follow the hyperlinks to read background information on the science related to the projects, and email the Chief Project scientist (bold font), for more information. If you are interested to apply to do a PhD on a particular project please submit your Expression of Interest application by the next deadline by clicking HERE.

Many Body quantum information

A/Prof Gavin Brennen: Macquarie University

*gavin.brennen@mq.edu.au

 There are several models for quantum computation which are equivalent in ability to simulate each other but which differ in how they operate. For example, in the measurement based model one begins with a special resource state (a 2D lattice of entangled spins with one spatial axis representing position on the computational register, the other time) and then performs adaptive single spin measurements on the remaining correlated spins to process a quantum computation.  This project will investigating how to prepare and process good resource states which are stable ground states of naturally occuring systems--i.e. computational phases of matter [1,2]. The scope of the research covers: encoding information in edge degrees of freedom [3] of two dimensional symmetry protected topological order, applying renormalization techniques to identify stable computational phases of matter [4], and analysis of how to use many body states are resources for precision measurement [5].

[1] G. K. Brennen and A. Miyake. Measurement-based quantum computer in the gapped ground state of a two-body hamiltonian. Phys. Rev. Lett., 101(1):010502 (2008).

[2] A.S. Darmawan, G.K. Brennen, and S.D. Bartlett, Measurement-based quantum comptuation in a two dimensional phase of matter, New J. Phys. 14, 013023 (2012). 

[3] J.M. Renes, A. Miyake, G.K. Brennen, S.D. Bartlett, Holonomic quantum computing in ground states of spin chains with symmetry-protected topological order, New Journal of Physics 15, 025020 (2013). 

[4] S.D. Bartlett, G.K. Brennen, A. Miyake, and J. Renes, Quantum Computational Renormalization in the Haldane Phase, Phys. Rev. Lett. 105, 110502 (2010). [5] S. Bartlett, G.K. Brennen, and A. Miyake, "Robust symmetry-protected metrology with the Haldane phase,' arXiv:1608.08221.

Topological Quantum Science

A/Prof. Gavin Brennen: Macquarie University

*gavin.brennen@mq.edu.au

We traditionally classify order in many body systems through the lens of Landau theory where the symmetry at the microscopic level is broken to a lower symmetry in the ground states, e.g. ordering of spins along one direction in the Ising model. In topological systems the opposite occurs, the ground states have emergent symmetries not present in the microscopic equations of motion. Such emergent properties include (1) non-locally degrees of freedom that can be used to store quantum information in a protected way and (2) anyons which are particles in 2D which have richer behavior under exchange than Bosons or Fermions. One project will investigate how to engineer spin lattices using trapped atom/molecules/ or photonic networks which have topological order and emergent anyons [1,4].   Further we investigate how to make braiding operations for anyons fault tolerant in physical realisations and possible novel applications such as computing the statistics of braided systems [3].  Another project will study the statistical mechanics of these anyons via discrete time dynamics described by quantum walks and in continuous time via anyonic Hubbard models.  Numerical studies will include using and extended already developed code for anyonic matrix product states (MPS) [5].

[1] G. K. Brennen, M. Aguado, and J. I. Cirac. Simulations of quantum double models. New J. Phys., 11:053009 (2009).

[2] L. Lehman, V. Zatloukan, G.K. Brennen, J.K. Pachos, and Z. Wang, Quantum Walks with Non-Abelian Anyons, Phys. Rev. Lett. 106, 230404 (2011).

[3] V. Zatloukan, L. Lehman, J.K. Pachos, and G.K. Brennen Transport properties of anyons in random topological environments, Physical Review B 90, 134201 (2014).

[4] T. Demarie, T. Linjordet, N. Menicucci, and G.K. Brennen, Detecting Topological Entanglement Entropy in a Lattice of Quantum Harmonic Oscillators, New Journal of Physics 16, 085011 (2014).

[5]  S. Singh, R. Pfeifer, G. Vidal, and G.K. Brennen, Matrix Product States and Efficient Simulation of Anyons, Physical Review B 89, 075112 (2014); B.M. Ayeni, S. Singh, R.N.C. Pfeifer, G.K. Brennen, Simulation of braiding anyons using Matrix Product States, Phys. Rev. B 93, 165128 (2016).

Quantum Simulations

A/Prof. Gavin Brennen: Macquarie University

*gavin.brennen@mq.edu.au

One of the great promises of quantum science is to simulate complex physical systems that are difficult to compute on classical machines. However, individual quantum systems are very fragile and to be useful in quantum devices for simulation, they must be accurately controlled. In the standard approach one must develop technology capable of controlling each and every individual quantum system within the device. The challenge of scaling up these control solutions to quantum devices containing hundred and perhaps millions of quantum systems seems incredibly daunting. We have shown how to run a quantum computer fault-tolerantly using semi-global operations and with very noisy measurements [1]. Here semi-global means the number of control modes (fields) is only very weakly dependent on the number of information carriers (specifically it scales logarithmically with the number of logical qubits) [2]. One project will study how apply these ideas to specific quantum simulation algorithms, particularly constant depth circuits and to compute a threshold on the individual gate errors. Another project will focus on how to use low depth quantum circuits to compute partition functions [3] for Lagrangians particularly in the context of continuous variable encodings using photonic networks. A third project will investigate analogue [4] and digital simulations of quantum field theories [5]. 

[1] G.A. Paz-Silva, G.K. Brennen, and J. Twamley, Fault Tolerance with Noisy and Slow Measurements and Preparation, Phys. Rev. Lett. 105, 100501 (2010). 

[2] G.A. Paz-Silva, G.K. Brennen, and J. Twamley, Bulk Fault Tolerant Quantum Information Processing with Boundary Addressability, New J. Phys. 13, 013011 (2011). 

[3] S. Iblisdir, M. Cirio, O. Boada, and G.K. Brennen, Low Depth Quantum Circuits for Ising Models, Annals of Physics 340, 205 (2014). 

[4] G.K. Brennen, G. Pupillo, E. Rico, T.M. Stace, and D. Vodola, "Loops and strings in a superconducting lattice gauge simulator," arXiv:1512.06565.

[5] G.K. Brennen, P. Rohde, B. Sanders, and S. Singh,  Multi-scale quantum simulation of quantum field theory using wavelets, Phys. Rev. A 92, 0323145 (2015);  "Holographic construction of quantum field theory using wavlets," arXiv:1606.05068.

Quantum Simulation of Quantum Chemistry

Berry Quantum Simulations PhD Scholarship Project

Dr. Dominic W Berry: Macquarie University
Prof. Alán Aspuru-Guzik: Harvard University

There are an enormous variety of technological challenges, such as renewable energy and pharmaceutical design, that could be solved if one could rapidly simulate molecules. The problem is that quantum systems are fundamentally difficult to simulate on normal “classical” computers. This led Feynman to propose the idea of quantum computers [1]. Later Lloyd gave a general quantum simulation algorithm [2], but it was Aspuru-Guzik and co-workers who showed how to simulate quantum chemistry on a quantum computer [3]. Unfortunately, this algorithm was relatively slow [4].

The goal of this PhD project is to develop techniques for quantum computers to simulate quantum chemistry that are much faster, and could enable quantum computers to simulate much larger molecules. The basic techniques to achieve this have been presented in a pair of papers by Berry and Aspuru-Guzik [5], and are based upon the ability to exponentially accelerate a numerical integral. This project will fully develop these techniques and devise ways to further improve the complexity, for example by showing how to better choose integration grids, and tailoring the algorithms for real molecules.

[1] R. Feynman, International Journal of Theoretical Physics 21, 467 (1982).
[2] S. Lloyd, Science 273, 1073 (1996).
[3] A. Aspuru-Guzik, A. D. Dutoi, P. J. Love, and M. Head-Gordon, Science 309, 1704 (2005).
[4] D. Wecker, B. Bauer, B. K. Clark, M. B. Hastings, and M. Troyer, Phys. Rev. A 90, 022305 (2014).
[5] R. Babbush, D. W. Berry, I. D. Kivlichan, A. Y. Wei, P. J. Love, and A. Aspuru-Guzik, arXiv:1506.01020; arXiv:1506.01029 (2015).

Optical trapping and Levitation of nanoparticles

Molina-Terriza Quantum Levitation PhD MSc Scholarship Project

A/Prof Thomas Volz: Macquarie University
Prof. Jason Twamley: Macquarie University

External collaborators: Prof. Gabriel Molina Terriza and Dr Mathieu Juan

*thomas.volz@mq.edu.au

In the Quantum Nanophotonics laboratories of Macquarie University, we have started a series of experiments showing that the the Physics of the Star Wars’ “tractor beam” was possible. Using electromagnetic radiation (an optical beam) we have managed to capture a small particle and move it around without physically touching the particle. This technique, which has led to a Nobel prize in physics and a whole new industry in biotechnology, could allow us to explore new physical regimes when we combine it with cooling the particle to the its quantum ground state. Nevertheless, the possibility of trapping small particles in vacuum (optical levitation) is still a battleground for physicists.

In this project we will set-up an experiment to trap and manipulate small particles in water, air and vacuum. We will use a continuous wave laser and a nanopositioner in order to beat the gravitation and van der Waal’s forces locking the particles to the substrates. We will explore different experimental techniques to increase the optical forces to levitate smaller and smaller dielectric particles.

This project is part of an ambitious project to observe quantum effects in dielectric particles, by isolating them from any decoherence due to the environment. Over a 3 year PhD program, the candidate will have the opportunity to use these techniques to cool the dielectric particle to ultralow temperatures and observe the quantum properties of a macroscopic object.

[1] Near-field Levitated Quantum Optomechanics with Nanodiamonds: Strong Single-Photon Coupling at Room Temperature arXiv:1505.03363

Quantum control of plasmonic structures with entangled photon states

Molina-Terriza PhD Scholarship Project on quantum plasmonics

A/Prof Gabriel Molina-Terriza*: Macquarie University
Prof. Javier Aizpurua: EHU
Prof. Anton Zeilinger: Univ. of Vienna

*gabriel.molina-terriza@mq.edu.au

The group of Prof. Gabriel Molina-Terriza (Macquarie University, Australia) offer a Ph.D. position to work in the field of quantum nanophotonics. The successful candidate will study both experimentally and theoretically the interaction of quantum states of light with nanoplasmonic structures. This is an exciting new field of research where several groups in the world are working to control the quantum properties of small metallic nanostructures. The extreme sensitivity of these quantum devices make them suitable to become the next generation of biosensors or to perform very precise measurements of electric and magnetic fields.

There are several PhD positions available in this research line, some of them could be carried out as a co-tutelle with other Universities, including the University of the Vasque Country (EHU) and the University of Vienna. The experimental research activity will be mainly developed in Macquarie University, where the candidate will benefit from the facilities in the group of Molina-Terriza, including a fully equipped quantum optics laboratory and nanofabrications and characterization facilities.

[1] Measurement and shaping of biphoton spectral wavefunctions, arXiv:1503.08629
[2] Angular momentum-induced circular dichroism in non-chiral nanostructures Nature Communications
[3] Twisted Photons Nature Physics

Self-Modifying Tensor Network Algorithms

Pfeifer PhD Scholarship Project on tensor network algorithms

Dr. Robert Pfeifer, robert.pfeifer@mq.edu.au
A/Prof. Gavin Brennen, gavin.brennan@mq.edu.au

Macquarie University

Tensor network algorithms are one of the most powerful techniques for the study of low-dimensional quantum systems. Indeed, one of the most successful numerical methods of all time, the Density Matrix Renormalisation Group algorithm [1], is a tensor network algorithm. However, the effectiveness of the algorithm depends very strongly on the extent to which its structure reflects the underlying (and possibly unknown) physics as well as the spatial structure of the system under study. The design of successful tensor network algorithms is very much a skilled art.

Using some of the latest developments in tensor network design [2,3], this project will investigate whether it is possible to make the networks design themselves, detecting both the spatial and entanglement structure of a physical system and organizing themselves appropriately.

[1] U. Schöllwock, Ann. Phys. 326, 96–192 (2011).
[2] G. Evenbly and R. N. C. Pfeifer, Phys. Rev. B 89, 245118 (2014).
[3] R. N. C. Pfeifer, J. Haegeman, and F. Verstraete, Phys. Rev. E 90, 033315 (2014).

Quantum logic in colour

Steel PhD Scholarship Project on quantum optics in frequency and time

Prof. Michael Steel: Macquarie University

In quantum mechanics, interference occurs whenever a given experimental outcome can come about in two or more ways. This means for instance that two photons incident from opposite sides of an oblique two-way mirror always leave as a pair. Weirdly, the two photons need not even reach the mirror at the same time: the interference occurs as long as we can’t tell which one arrived first. This surprising phenomenon is at the heart of photonic approaches to quantum information processing, including including quantum metrology, boson sampling, and optical quantum computing. These operations have been thoroughly investigated in real space, but there are even stranger analogs which are much less studied: it should be possible to see interference of two photons of completely different colour.

In this project we will explore the description and design of quantum logic gates and processes in the frequency and time domains. We will design nonlinear optical devices that enable the quantum interference of photons of different frequencies, including the optimisation and suppression of competing frequency conversion processes. Connections to classical optics will be pursued to facilitate ease of laboratory characterisation and implementation. There will be close interaction with experimental teams working on these and similar ideas.
Z. Chaboyer, T. Meany, L. G. Helt, M. J. Withford, and M. J. Steel, Tunable quantum interference in a 3D integrated circuit Scientific Reports 5, 9601:1–5 (2015)

L. G. Helt, J. E. Sipe, and M. J. Steel, Spontaneous parametric downconversion in waveguides: What’s loss got to do with it? New Journal of Physics 17, 013055:1–17 (2015)

M. J. Collins, C. Xiong, I. H. Rey, T. D. Vo, J. He, S. Shahnia, C. Reardon, T. F. Krauss, M. J. Steel, A. S. Clark, and B. J. Eggleton, Integrated spatial multiplexing of heralded single photon sources Nature Communications 4, 2582:1–7 (2013)

M. K. Dezfouli, M. J. Steel, J. E. Sipe and M. M. Dignam, Heisenberg treatment of pair-generation in lossy coupled-cavity systems Physical Review A 90, 043832:1–12 (2014)

Single Spin Sensing with Nano Diamonds

Single spin sensing PhD project in the Volz group.

Dr Thomas Volz*: Macquarie University
Dr Sarah Kaiser: Macquarie University

*thomas.volz@mq.edu.au

The Quantum Materials and Applications group at Macquarie University Sydney is looking for an interested and highly motivated individual to work on a PhD project on nanoscale single-spin sensing with defect centres in (nano-)diamonds. The technique of using single NV centres for magnetic field sensing down to the nT/sqrt(Hz) level in different contexts is well established in the field and has been applied to different scenarios including magnetic-field sensing in biological contexts [1]. This project aims at implementing a low-temperature single-spin sensing platform based on a closed-cycle cryostat and a commercially available AFM platform. The platform will be used for studying novel and exotic solid-state materials and for exploring their potential for real-world applications. The student should bring a strong interest in technology and a good understanding and working knowledge of quantum mechanics. Previous experience in the field is a plus but not absolutely necessary.

If you are interested in the project please contact Dr Thomas Volz (thomas.volz@mq.edu.au) and/or Dr Carlo Bradac (carlo.bradac@mq.edu.au).

[1] L. Rondin, J.-P. Tetienne, T. Hingant, J.-F. Roch, P. Maletinsky, and V. Jacques Magnetometry with nitrogen-vacancy defects in diamond Rep. Prog. Phys. 77, 056503 (2014)

Parity-Time symmetry phase transitions in quantum opto-acoustic systems

msteel_twamley_parity

A/Prof Michael Steel, michael.steel@mq.edu.au
Prof. Jason Twamley, jason.twamley@mq.edu.au

Conventional quantum mechanics of isolated systems is built upon the assumption of a Hermitian Hamiltonian to ensure physical real-valued energy levels. Parity-Time symmetric (PT) quantum systems are attracting enormous interest in the community. PT systems, while not Hermitian, still exhibit real eigenenergies and display complex and interesting behaviors. In particular such systems support a discontinuous phase transition when a control parameter is varied and PT symmetry is broken. Surprisingly, PT-symmetry breaking enables potentially very useful properties for technologies eg. non-reciprocal optical devices [1], enhancement of optomechanical coupling [2], and phonon/photon enhanced couplings.

In this project, we will explore the novel phase transitions that appear in PT related materials and in particular in systems that couple light to elastic vibrations (phononics) [4,5], and also to spin (spintronics). Such systems will have many potential applications ranging from novel types of sensors through to the quenching of quantum phase transitions. During the project you will learn techniques (analytic and numeric), in advanced photonics and acoustics, techniques related to quantum spin physics and the design and simulation of ultra-precise sensors [3].

Back to the top of this page