Impact of anisotropy on vortex clusters and their dynamics

TL;DR

This paper explores how anisotropy influences the stability and dynamics of vortex clusters in Bose-Einstein condensates, revealing that anisotropy can both stabilize and destabilize vortex configurations and providing a comprehensive analysis across different regimes.

Contribution

It introduces a detailed analysis of vortex cluster stability under anisotropy, including bifurcation analysis and a particle-like dynamical model, advancing understanding of vortex behavior in anisotropic traps.

Findings

Anisotropy stabilizes vortex states unstable in isotropic traps.

Anisotropy destabilizes some stable isotropic vortex states.

Good agreement between analytical models and numerical simulations.

Abstract

We investigate the effects of anisotropy on the stability and dynamics of vortex cluster states which arise in Bose-Einstein condensates. Sufficiently strong anisotropies are shown to stabilize states with arbitrary numbers of vortices that are highly unstable in the isotropic limit. Conversely, anisotropy can be used to destabilize states which are stable in the isotropic limit. Near the linear limit, we identify the bifurcations of vortex states including their emergence from linear eigenstates, while in the strongly nonlinear limit, a particle-like description of the dynamics of the vortices in the anisotropic trap is developed. Both are in very good agreement with numerical results. Collective modes of stabilized many vortex cluster states are demonstrated.