Generation and Decay of Two-Dimensional Quantum Turbulence in a Trapped Bose-Einstein Condensate

TL;DR

This paper investigates the formation and decay of two-dimensional quantum turbulence in a trapped Bose-Einstein condensate, combining experimental insights with mean-field simulations to understand vortex dynamics and thermal effects.

Contribution

It provides a detailed simulation-based analysis of vortex formation, decay, and the influence of thermal dissipation in quantum turbulence within BECs, aligning with experimental results.

Findings

Vortex formation from superfluid flow past an obstacle

Disordered vortex states develop over time

Vortex decay involves annihilation and boundary interactions

Abstract

In a recent experiment, Kwon et. al (arXiv:1403.4658 [cond-mat.quant-gas]) generated a disordered state of quantum vortices by translating an oblate Bose-Einstein condensate past a laser-induced obstacle and studying the subsequent decay of vortex number. Using mean-field simulations of the Gross-Pitaevskii equation, we shed light on the various stages of the observed dynamics. We find that the flow of the superfluid past the obstacle leads initially to the formation of a classical-like wake, which later becomes disordered. Following removal of the obstacle, the vortex number decays due to vortices annihilating and reaching the boundary. Our results are in excellent agreement with the experimental observations. Furthermore, we probe thermal effects through phenomenological dissipation.