Quantum kinetic theory VII: The influence of vapor dynamics on condensate growth

TL;DR

This paper extends quantum kinetic models of Bose-Einstein condensate growth by incorporating vapor dynamics, revealing a speedup at high condensate fractions and analyzing temperature effects, with implications for experimental comparisons.

Contribution

It introduces a numerical solution of a modified quantum Boltzmann equation including vapor dynamics, improving the understanding of condensate growth regimes.

Findings

Good agreement with previous models at low condensate fractions

Significant speedup observed at higher condensate fractions

Temperature has a surprisingly small effect on growth dynamics

Abstract

We extend earlier models of the growth of a Bose-Einstein condensate to include the full dynamical effects of the thermal cloud by numerically solving a modified quantum Boltzmann equation. We determine the regime in which the assumptions of the simple model are a reasonable approximation, and compare our new results with those that were earlier compared with experimental data. We find good agreement with our earlier modelling, except at higher condensate fractions, for which a significant speedup is found. We also investigate the effect of temperature on condensate growth, and find that this has a surprisingly small effect. The discrepancy between theory and experiment remains, since the speedup found in these computations does not occur in the parameter regime specified in the the experiment.