Spontaneous creation of skyrmions in a two-component Bose-Einstein condensate

TL;DR

This paper demonstrates that in a two-component Bose-Einstein condensate, overlapped vortex rings can spontaneously separate and form linked vortex structures called skyrmions, revealing a new mechanism for topological defect creation.

Contribution

It shows the spontaneous formation of skyrmions from vortex rings in a two-component BEC through numerical and analytical methods.

Findings

Overlapped vortex rings are dynamically unstable.

Linked vortex rings can form, creating skyrmions.

Parameter ranges for skyrmion formation are identified.

Abstract

We investigate the stability of a vortex ring in a miscible two-component Bose-Einstein condensate confined in a harmonic potential, where the vortex cores in the two components are initially overlapped. Solving the Gross-Pitaevskii equation numerically, we find that the overlapped vortex rings in the two components are dynamically unstable against separation and that they can form linked vortex rings, resulting in a three-dimensional skyrmion. The parameter range for spontaneous skyrmion generation is determined by the Bogoliubov analysis