Thermally induced instability of a doubly quantized vortex in a Bose-Einstein condensate

TL;DR

This paper investigates how small thermal fluctuations can cause a doubly quantized vortex in a Bose-Einstein condensate to split into two singly quantized vortices, highlighting the sensitivity of vortex stability to thermal noise.

Contribution

The study uses 3D Gross-Pitaevskii simulations with thermal noise to analyze vortex instability, revealing the impact of minimal thermal atoms on vortex decay.

Findings

Small thermal fluctuations (10-15%) induce vortex splitting within tens of milliseconds.

Vortex lifetime decreases monotonically with increasing interaction strength.

Thermal noise significantly affects vortex stability in Bose-Einstein condensates.

Abstract

We study the instability of a doubly quantized vortex topologically imprinted on $^{23}$Na condensate, as reported in recent experiment [Phys. Rev. Lett. \textbf{93}, 160406 (2004)]. We have performed numerical simulations using three-dimensional Gross-Pitaevskii equation with classical thermal noise. Splitting of a doubly quantized vortex turns out to be a process that is very sensitive to the presence of thermal atoms. We observe that even ve ry small thermal fluctuations, corresponding to 10 to 15% of thermal atoms, ca use the decay of doubly quantized vortex into two singly quantized vortices in tens of milliseconds. As in the experiment, the lifetime of doubly quantized vortex i s a monotonic function of the interaction strength.