Polar core vortex dynamics in disc-trapped homogeneous spin-1 Bose-Einstein condensates

TL;DR

This paper investigates the complex behavior of polar core vortices in a two-dimensional spin-1 Bose-Einstein condensate, revealing how boundary effects and magnetic fields influence vortex motion and interactions.

Contribution

It provides a detailed analysis of vortex dynamics in a disc-trapped spin-1 BEC, including effects of boundary conditions and magnetic fields, which was not comprehensively studied before.

Findings

Vortices move radially outward due to boundary interactions.

Opposite sign vortex pairs attract and move inward or outward based on attraction strength.

Same sign vortex pairs repel each other and exhibit spiral dynamics.

Abstract

We study the dynamics of polar core vortices in the easy plane phase of an atomic spin-1 Bose-Einstein condensate confined in a two-dimensional disc potential. A single vortex moves radially outward due to its interaction with background flows that arise from boundary effects. Pairs of opposite sign vortices, which tend to attract, move either radially inward or outward, depending on their strength of attraction relative to boundary effects. Pairs of same sign vortices repel. Spiral vortex dynamics are obtained for same-sign pairs in the presence of a finite axial magnetization. We quantify the dynamics for a range of realistic experimental parameters, finding that the vortex dynamics are accelerated with increasing quadratic Zeeman energy, consistent with existing studies in planar systems.