Dynamics of a single ring of vortices in two-dimensional trapped Bose-Einstein condensates

TL;DR

This paper investigates the behavior and stability of vortex rings in two-dimensional Bose-Einstein condensates, analyzing their ground states and excitations in both uniform and trapped conditions.

Contribution

It provides a detailed analysis of vortex ring dynamics, including stability and excitation spectra, in different trapping scenarios for Bose-Einstein condensates.

Findings

Identification of ground state configurations as a function of rotation frequency

Analysis of Tkachenko-like excitations and their stability

Comparison between uniform and trapped condensate behaviors

Abstract

The dynamics of a ring of vortices in two-dimensional Bose-Einstein condensates (with and without an additional vortex at the center) is studied for (1) a uniform condensate in a rigid cylinder and (2) a nonuniform trapped condensate in the Thomas-Fermi limit. The sequence of ground states (within these single-ring configurations) is determined as a function of the external rotation frequency by comparing the free energy of the various states. For each ground state, the Tkachenko-like excitations and the associated dynamical stability are analyzed.