Annular Bose-Einstein Condensates in the Lowest Landau Level

TL;DR

This paper investigates the properties and arrangements of vortices in a rotating annular Bose-Einstein condensate using the Gross-Pitaevskii model restricted to the Lowest Landau Level, combining theoretical analysis and numerical simulations.

Contribution

It provides a theoretical and numerical study of vortex configurations in annular BECs within the Lowest Landau Level approximation, revealing vortex lattice distortions and multiply quantized vortices.

Findings

Vortices form a distorted lattice pattern.

Multiply quantized vortices appear in the central hole.

Vortex locations are determined through numerical minimization.

Abstract

A rotating superfluid such as a Bose-Einstein condensate is usually described by the Gross-Pitaevskii (GP) model. An important issue is to determine from this model the properties of the quantized vortices that a superfluid nucleates when set into rotation. In this paper we address the minimization of a two dimensional GP energy functional describing a rotating annular Bose-Einstein condensate. In a certain limit it is physically relevant to restrict the minimimization to the Lowest-Landau-Level, that is the first eigenspace of the Ginzburg-Landau operator. Taking the particular structure of this space into account we obtain theoretical results concerning the vortices of the condensate. We also compute the vortices' locations by a numerical minimization procedure. We find that they lie on a distorted lattice and that multiply quantized vortices appear in the central hole of low matter density.