Vortex lattice of a Bose-Einstein Condensate in a rotating anisotropic trap

TL;DR

This paper analyzes vortex lattice formations in a Bose-Einstein Condensate within a rotating anisotropic trap, revealing how vortex configurations depend on interaction strength and trap anisotropy, with implications for understanding superfluid behavior.

Contribution

It provides exact solutions for single particle wavefunctions in anisotropic traps and explores vortex configurations for different vortex numbers, highlighting the effects of anisotropy.

Findings

Vortex lattices remain triangular in many-vortex limit.

Vortex lattice planes align with the trap's weak axis.

Vortex configurations differ significantly from symmetric traps for few vortices.

Abstract

We study the vortex lattices in a Bose-Einstein Condensate in a rotating anisotropic harmonic trap. We first investigate the single particle wavefunctions obtained by the exact solution of the problem and give simple expressions for these wavefunctions in the small anisotropy limit. Depending on the strength of the interactions, a few or a large number of vortices can be formed. In the limit of many vortices, we calculate the density profile of the cloud and show that the vortex lattice stays triangular. We also find that the vortex lattice planes align themselves with the weak axis of the external potential. For a small number of vortices, we numerically solve the Gross-Pitaevskii equation and find vortex configurations that are very different from the vortex configurations in an axisymmetric rotating trap.