QFG @Otago - Research

Quantum Fluid Dynamics

Superfluids flow without resistance, a striking collective quantum many-body phenomenon. Yet even superfluids have their limits - force a superfluid just right and vortices will nucleate, a form of quantum viscosity. In atomic Bose-Einstein condensates (BEC) forcing can excite compressible phonons and incompressible vortices, providing different pathways for energy transport. We explore turbulent dynamics of quantum fluids, both dilute gas BECs, and novel analogue systems such as quantum fluids of light.

Open Quantum Systems

Real quantum systems are not isolated, and contact with the environment causes decoherence. In many-body quantum systems multiple decay channels determine the lifetime of superfluid excitations such as vortices and solitons. These stable excitations can also form during the phase transition to BEC, a process that is also well described by an open systems theory. We explore dissipative mechanisms for excited many-body systems and limits to superfluidity.

Quantum Optics

Many-body entanglement is central to many quantum phenomena. The interaction of light and matter generates entanglement between photons and atoms, sometimes in the form of useable quantum entanglement created via controlled nonlinear processes, for example in four photon interactions. Entanglement can be well understood in quantum phase space, the playground of quantum optics theory. We study measures of entanglement, and entanglement resources for quantum information applications.