We numerically study the phase ordering dynamics of a uniform 2D Bose gas following a quench into the superfluid phase, using the classical field methodology. We explore the crossover between conservative and dissipative evolution, finding clear evidence for universal behaviour in the dynamics, regardless of the dissipation strength. This universal behaviour manifests as a power-law growth of the correlation length in time ~t(1/z), characterised by the dynamical exponent z.
In the fully dissipative limit, we find the exponent to be consistent with z=2 with logarithmic corrections to the power-law scaling, as seen in previous studies. Decreasing the dissipation towards the conservative limit, we observe a smooth crossover in z that converges to an anomalous value distinctly lower than 2 at a small finite dissipation strength. We show that this lower exponent may be attributable to a power-law vortex mobility arising from interactions between vortices and sound waves in the system.
About the presenter
Dr. Andrew Groszek is a theorist that has recently joined FLEET to work as a research fellow with CI Matthew Davis at the University of Queensland. His research will focus on non-equilibrium quantum systems, in collaboration with the laboratory of CI Kristian Helmerson at Monash University.