Finite temperature expansion dynamics of Bose-Einstein condensates

TL;DR

This paper investigates how finite temperature and changes in trap geometry affect the expansion dynamics of Bose-Einstein condensates, revealing temperature-dependent interference patterns and density distribution features.

Contribution

It introduces the frozen thermal cloud approximation to study finite temperature effects on BEC expansion and compares dynamics between multiply and simply connected geometries.

Findings

Finite temperature causes more pronounced interference rings during expansion.

Geometry transformation from multiply to simply connected alters density distribution.

Finite temperature effects are significant in the initial stages of BEC expansion.

Abstract

We explore the effects of finite temperature on the dynamics of Bose-Einstein condensates (BECs) after it is released from the confining potential. In addition, we examine the variation in the expansion dynamics of the BECs as the confining potential is transformed from a multiply to a simply connected geometry. To include the effects of finite temperatures we use the frozen thermal cloud approximation, and observe unique features of the condensate density distribution when released from the confining potential. We find that at $T\neq 0$, during the initial stages of expansion, the multiply connected condensate has more pronounced interference rings compared to the case of zero temperature. Such difference in the dynamical evolution is also evident for simply connected condensates.