Dark soliton dynamics in Bose-Einstein condensates at finite temperature

TL;DR

This paper investigates how dark solitons in elongated Bose-Einstein condensates decay over time at finite temperatures, highlighting the influence of thermal clouds and initial velocities on soliton stability.

Contribution

It introduces numerical simulations that accurately model finite-temperature effects on dark soliton dynamics, aligning well with experimental observations.

Findings

Solitons oscillate with increasing amplitude at finite temperatures.

Decay times decrease with higher temperature and initial velocity.

Simulation results agree with experimental data from S. Burger et al.

Abstract

The dynamics of a dark soliton in an elongated Bose-Einstein condensate at finite temperatures is studied using numerical simulations. We find that in the presence of harmonic confinement the soliton may oscillate even at finite temperatures, but with an amplitude that increases with time, indicating the decay of the soliton. The timescale of this decay decreases both with increasing temperature and with increasing initial soliton velocity. Simulations performed for the experiment of S. Burger et al., Phys. Rev. Lett. 83, 5198 (1999), reveal excellent agreement with the observed soliton decay, confirming the crucial role of the thermal cloud in soliton dynamics.