Non-Equilibrium description of ultra-cold Bose gases: beyond the mean field
We have developed a methodology, based on the truncated Wigner approximation, that treats effects arising from quantum and thermal fluctuations in trapped ultra-cold bosons. This talk presents an overview of our ‘c-field’ method, and its application to a range of equilibrium and dynamical phenomena. We show how a condensate can be identified in non-equilibrium systems, and present quantitative calculations of the thermodynamic properties and correlations of the accompanying thermal cloud. We discuss the description of vortex dynamics and formation, including the results of recent experiments. A critical comparison is made between c-field and symmetry-breaking methods.