Quantum kinetic theory of trapped atomic gases

TL;DR

This paper develops a comprehensive quantum kinetic framework using a Fokker-Planck equation to accurately describe the non-equilibrium dynamics of trapped atomic gases, including phase transitions and collective modes.

Contribution

It introduces a novel Fokker-Planck approach that captures dynamics across phase transitions, surpassing traditional mean-field theories.

Findings

Effective description of non-equilibrium dynamics

Application to Bose-Einstein condensation

Analysis of collective modes

Abstract

We present a general framework in which we can accurately describe the non-equilibrium dynamics of trapped atomic gases. This is achieved by deriving a single Fokker-Planck equation for the gas. In this way we are able to discuss not only the dynamics of an interacting gas above and below the critical temperature at which the gas becomes superfluid, but also during the phase transition itself. The last topic cannot be studied on the basis of the usual mean-field theory and was the main motivation for our work. To show, however, that the Fokker-Planck equation is not only of interest for recent experiments on the dynamics of Bose-Einstein condensation, we also indicate how it can, for instance, be applied to the study of the collective modes of a condensed Bose gas.