QFG @Otago - Research

Quantum Fluid Dynamics

Superfluids flow without resistance—one of the most striking manifestations of quantum many-body physics. Push them hard enough, however, and this perfection breaks—quantized vortices nucleate, a form of quantum viscosity. Driven Bose–Einstein condensates support both compressible phonons and incompressible vortices, providing distinct channels for energy transport in turbulent motion. We investigate turbulence in quantum fluids, spanning dilute-gas BECs and analogue systems such as quantum fluids of light.

Open Quantum Systems

Real quantum systems never evolve in isolation—coupling to the environment drives decoherence and dissipation. In many-body systems, multiple decay channels set the lifetime of superfluid excitations such as vortices and solitons. These robust structures can also emerge spontaneously during the phase transition to Bose–Einstein condensation—a process naturally captured by open-systems theory. We investigate dissipative dynamics in excited quantum fluids and identify the fundamental limits of superfluidity.

Quantum Optics

Many-body entanglement underpins the most profound phenomena in quantum physics. By driving controlled light–matter interactions, we generate entanglement between photons and atoms, converting nonlinear dynamics into practical quantum resources. Quantum phase space—the natural language of quantum optics—reveals the structure and strength of these correlations. We develop and apply entanglement measures to identify, characterise, and harness entanglement for quantum information technologies.