Quantum science and technology

Supervisor: Associate Professor James Downes

Topic description

This PhD project will investigate the diamagnetic levitation of insulating micro-particles in ultra-high vacuum as a route to creating ultra-high-quality factor (Q) mechanical oscillators.

By eliminating mechanical clamping losses, diamagnetic levitation offers a promising platform for studying extremely low-dissipation mechanical motion and developing next-generation precision sensing technologies. The project will involve the design, construction and characterisation of experimental levitation systems capable of stable operation under ultra-high vacuum conditions.

A key component of the research will be the development of optical position sensing and active feedback control systems capable of measuring and cooling all six mechanical degrees of freedom of the levitated object.

The candidate will combine advanced optical, electronic and control techniques with theoretical modelling of mechanical dynamics, noise processes and feedback cooling mechanisms. The project is primarily experimental but will include complementary theoretical and numerical investigations to guide system design and performance optimisation.

The long-term goal of the research is to develop levitated mechanical systems with unprecedented force and acceleration sensitivity. Such devices have potential applications in inertial sensing, precision acceleration measurement and, ultimately, quantum-enhanced gravimetry.

The project will be conducted within an established international collaboration with researchers at the Okinawa Institute of Science and Technology, providing opportunities for close interaction with leading experts in levitated optomechanics and quantum sensing.

Supervisor: Professor Michael Steel

Topic description

Raman spectroscopy is a ubiquitous optical technique for detecting and analysing trace quantities of molecules and proteins in various scenarios, including environmental monitoring, explosives detection and biosecurity. Recent breakthroughs have allowed direct observation of the stretching of individual atomic bonds and even control of chemical reactions.

In this project, we will show how quantum imaging can push past the classical constraints of Raman microscopy to improve the resolution, sensitivity and contrast of Raman microscopes. This will be achieved by leveraging quantum advantages across the three key stages of the Raman measurement process:

• exciting the molecule with nonclassical light
• controlling the quantum state of the internal molecular vibrations
• optimising detection protocols to efficiently extract the information encoded in the scattered light.

The work will involve advanced techniques in theoretical quantum optics that examine the role of non-classical states in each stage of the Raman process: illumination, excitation and emission.

Techniques may involve analytic and numerical solution of quantum optical master equations, a formalism known as molecular optomechanics and the application of quantum measurement optimisation techniques.

The project involves collaboration with partners in Brisbane, Spain and the United States.

Supervisor: Professor Richard Mildren

Topic description

A PhD position is available in the area of ultra-stable laser physics and optical frequency control. The project will investigate compact monolithic diamond Raman lasers with ultra-narrow linewidths for next-generation optical atomic clocks and precision sensing.

The research combines nonlinear optics, laser stabilisation, photonics, and advanced optical materials, with opportunities to work on state-of-the-art frequency metrology and international collaborations in optical clocks and quantum technologies.

Within a highly collaborative research environment, the successful candidate will develop expertise in:

• feedback control
• high-performance laser systems
• photonics engineering
• precision measurement.

Applicants with backgrounds in physics, photonics, optics, electrical engineering or related disciplines are encouraged to apply.

Supervisor: Professor Richard Mildren

Topic description

A PhD position is available in the emerging area of self-referenced laser stabilisation and optical frequency control. The project will explore a new approach to ultra-stable lasers in which thermal drift is measured and corrected internally using stress-induced birefringence in diamond resonators.

The research spans precision photonics, laser stabilisation, nonlinear optics and optical metrology, with applications in portable optical atomic clocks, quantum technologies, navigation and precision sensing. The successful candidate will collaborate with leading international groups in optical clocks and precision metrology and work on:

• advanced feedback systems
• compact resonator platforms
• dual-frequency laser operation
• frequency-noise analysis.

Applicants with backgrounds in physics, photonics, optics, electrical engineering, control systems or related disciplines are encouraged to apply.

Supervisor: Professor Daniel Terno

Topic description

Information is physical – the rules of information processing are determined by the physics of its carriers.

Relativistic quantum information asks how these rules change when quantum systems move at relativistic speeds, propagate through curved spacetime or are detected by observers whose motion and gravitational environment cannot be ignored. Its aim is to understand how relativity modifies performance of information-processing tasks and how quantum info can help the fundamental physics.

Quantum systems are now deployed over long baselines and in space, where distances, velocities, gravitational redshifts and time delays exceed what can be achieved in ground-based laboratories. At the same time, quantum-enhanced metrology is approaching the precision at which weak relativistic effects may become measurable signals or limiting noise sources.

This PhD project will develop theoretical tools for quantum interferometry and metrology in relativistic settings. Possible directions include:

• Hong-Ou-Mandel interference as a probe of relativistic time delays
• possible effects of exotic physics on atomic clocks
• quantum-optical tests of the equivalence principle
• structured-light states in weak gravitational fields.

The project will begin from this common framework, with one specific direction selected for detailed development by the student.

Supervisor: Professor Gavin Brennen

Topic description

This project aims to explain how spacetime may emerge from quantum information, addressing shortcomings in quantum field theory to make it fit better with gravity.

Inspired by ideas from image compression and the physics of sound waves, the project will use innovative tools like wavelets, holography, and sonic relativity to develop a new framework for understanding emergent geometry and relativistic phenomena.

Expected outcomes include advanced computational techniques which can be tested on mature quantum technologies and insights into the fundamental nature of spacetime.

Topics involved:

• functional analysis
• quantum computation and simulation
• quantum field theory.