Thermal Fluctuations of Vortex Matter in Trapped Bose-Einstein Condensates

TL;DR

This study uses Monte Carlo simulations to explore thermal vortex fluctuations in three-dimensional trapped Bose-Einstein condensates, revealing complex phase transitions and vortex behaviors influenced by temperature and confinement.

Contribution

It introduces a detailed Monte Carlo analysis of vortex matter in trapped BECs, highlighting novel vortex phase transitions and fluctuation effects.

Findings

Vortex fluctuations are dominant near the cylinder wall in rotating helium.

A transition from vortex solid to vortex tangle occurs near the trap edge at low temperatures.

An intermediate vortex liquid phase may exist at higher temperatures.

Abstract

We perform Monte Carlo studies of vortices in three dimensions in a cylindrical confinement, with uniform and nonuniform density. The former is relevant to rotating 4He, the latter is relevant to a rotating trapped Bose--Einstein condensate. In the former case we find dominant angular thermal vortex fluctuations close to the cylinder wall. For the latter case, a novel effect is that at low temperatures the vortex solid close to the center of the trap crosses directly over to a tension-less vortex tangle near the edge of the trap. At higher temperatures an intermediate tensionful vortex liquid located between the vortex solid and the vortex tangle, may exist.