Noisy Dynamics of a Vortex in a Partially Bose-Einstein Condensed Gas

TL;DR

This paper models the stochastic dynamics of a vortex in a partially Bose-Einstein condensed gas at nonzero temperature, revealing how thermal fluctuations influence vortex lifetime and motion.

Contribution

It introduces a variational approach to derive stochastic equations of motion for vortices, incorporating thermal fluctuations in a partially condensed Bose gas.

Findings

Vortex lifetime is finite due to thermal fluctuations.

Derived stochastic equations describe vortex spiral-out dynamics.

Thermal effects significantly impact vortex stability.

Abstract

We study the dynamics of a straight vortex line in a partially Bose-Einstein condensed atomic gas. Using a variational approach to the stochastic field equation that describes the dynamics of the condensate at nonzero temperature, we derive the stochastic equations of motion for the position of the vortex core. Using these results, we calculate the time it takes the vortex to spiral out of the condensate. Due to the fact that we include thermal fluctuations in our description, this lifetime of the vortex is finite even if its initial position is in the center of the condensate.