# Prof. Matthew Davis

### Chief Investigator, Professor

Dr Matthew Davis' research interests are in the area of the quantum behaviour of ultra-cold gases and Bose-Einstein Condensation. He did his undergraduate studies in physics at the University of Otago in Dunedin, New Zealand, before completing his PhD at the University of Oxford in 2001 under the supervision of Professor Keith Burnett. His chief research interests are methods for nonequilibrium dynamics of Bose gases formation of BECs generation of correlations in ultra-cold gases computational physics.

### 2019

We experimentally realize a highly tunable superfluid oscillator circuit in a quantum gas of ultracold atoms and develop and verify a simple lumped-element description of this circuit.

Adding energy to a system through transient stirring usually leads to more disorder. In contrast, point-like vortices in a bounded two-dimensional fluid are predicted to reorder above a certain energy, forming persistent vortex clusters.

### 2018

Rapidly scanning magnetic and optical dipole traps have been widely utilized to form time-averaged potentials for ultracold quantum gas experiments.

### 2016

The development of novel trapping potentials for degenerate quantum gases has been an important factor driving experimental progress in the field. The introduction of spatial light modulators (SLMs) into quantum gas laboratories means that a range of configurable geometries are now possible.

Interferometric measurements with matter waves are established techniques for sensitive gravimetry, rotation sensing, and measurement of surface interactions, but compact interferometers will require techniques based on trapped geometries.

### 2013

The study of dynamical tunneling in a periodically driven anharmonic potential probes the quantum-classical transition via the experimental control of the effective Planck's constant for the system.

### 2011

We study the formation of a Bose-Einstein condensate in a cigar-shaped three-dimensional harmonic trap, induced by the controlled addition of an attractive “dimple” potential along the weak axis.

### 2009

We observe the formation of shock waves in a Bose-Einstein condensate containing a large number of sodium atoms. The shock wave is initiated with a repulsive blue-detuned light barrier, intersecting the Bose-Einstein condensate, after which two shock fronts appear.

### 2008

We propose and investigate a technique for generating smooth two-dimensional potentials for ultra-cold atoms based on the rapid scanning of a far-detuned laser beam using a two-dimensional acousto-optical modulator (AOM).

### ARC Centre of Excellence for Engineered Quantum Systems (EQUS) (2011–2022)

Abstract: The future of technology lies in controlling the quantum world. The ARC Centre of Excellence for Engineered Quantum Systems (EQuS) will deliver the building blocks of future quantum technologies and, critically, ensure Australian primacy in this endeavour. Three strategic research programs will target Quantum Measurement and Control; Synthetic Quantum Systems and Simulation; and Quantum-Enabled Sensors and Metrology.

### ARC Discovery Projects: Riding a quantum wave: transport and flow of atomic quantum fluids (2015–2018)

Abstract: In our lab, we use lasers and magnetic fields to cool tiny samples of millions of atoms to temperatures a few billionths of a degree above absolute zero. At such cold temperatures they form a superfluid known as a Bose-Einstein condensate, that flows with zero viscosity. Using tailored light fields to trap and guide the atoms, we will build rudimentary atomic circuits, and coax the superfluid to flow through a channel between two reservoirs, firstly with thermodynamic gradients, and secondly by building a quantum pump.

### ARC Discovery Projects: Spin vortex dynamics in a ferromagnetic superfluid (2020-2023)

Magnetic spin vortices are stable whirlpool-like objects that can spontaneously form when magnetic materials are rapidly cooled. This project aims to understand and manipulate spin vortices in a magnetic quantum fluid, one of the cleanest and most controllable magnetic systems. The significance is that spin vortices are potentially fundamental elements of future electronic technologies for advanced storage and logic. The expected outcomes are the ability to create spin vortices on demand, and the characterisation of their suitability for future applications.