Nucleation of vortex arrays in rotating anisotropic Bose-Einstein condensates

TL;DR

This paper investigates how vortices form and arrange in rotating anisotropic Bose-Einstein condensates using numerical simulations, revealing the influence of rotation speed and trap shape on vortex nucleation and array structures.

Contribution

It provides a detailed numerical analysis of vortex nucleation in anisotropic traps, highlighting the critical rotation frequency and the impact of trap geometry on vortex arrangements.

Findings

Vortices appear at rotation frequencies above the critical threshold.

Vortex array structures are strongly affected by trap anisotropy.

Nucleation follows a critical velocity mechanism.

Abstract

The nucleation of vortices and the resulting structures of vortex arrays in dilute, trapped, zero-temperature Bose-Einstein condensates are investigated numerically. Vortices are generated by rotating a three-dimensional, anisotropic harmonic atom trap. The condensate ground state is obtained by propagating the Gross-Pitaevskii equation in imaginary time. Vortices first appear at a rotation frequency significantly larger than the critical frequency for vortex stabilization. This is consistent with a critical velocity mechanism for vortex nucleation. At higher frequencies, the structures of the vortex arrays are strongly influenced by trap geometry.