Hydrodynamic generation of skyrmions in a two-component Bose-Einstein condensate

TL;DR

This paper proposes a method to generate three-dimensional skyrmions in a two-component Bose-Einstein condensate by moving an obstacle faster than a critical velocity, resulting in linked vortex rings that can be stabilized into trains.

Contribution

It introduces a novel technique to create and stabilize skyrmions in BECs using component-dependent obstacle potentials and guiding potentials.

Findings

Skyrmions are generated behind a moving obstacle in a two-component BEC.

Linked vortex rings form the skyrmions in different components.

Guiding potentials prolong skyrmion lifetime and enable skyrmion train formation.

Abstract

When an obstacle is moved in a superfluid faster than a critical velocity, quantized vortices are generated behind the obstacle. Here we propose a method to create more complicated topological excitations, three-dimensional skyrmions, behind a moving obstacle. We numerically show that, in a two-component Bose-Einstein condensate, component-dependent obstacle potentials can generate skyrmions in the wake, made up of quantized vortex rings in different components that are linked with each other. The lifetime of generated skyrmions can be prolonged by a guiding potential, which enables the formation of a skyrmion train.