Vortices on demand in multicomponent Bose-Einstein condensates

TL;DR

This paper introduces a straightforward method to generate vortices at specific locations in multicomponent Bose-Einstein condensates by manipulating magnetic fields, with potential experimental realization using ultracold rubidium gases.

Contribution

It presents a novel mechanism for creating and controlling vortices in multicomponent BECs through magnetic field interactions, supported by analytical and numerical analysis.

Findings

Vortices form where spin-transverse field interaction vanishes.

Vortices can have different topological charges depending on magnetic field order.

Vortices can spontaneously appear in any spin component under certain conditions.

Abstract

We present a simple mechanism to produce vortices at any desired spatial locations in harmonically trapped Bose-Einstein condensates (BEC) with multicomponent spin states coupled to external transverse and axial magnetic fields. The vortices appear at the spatial points where the spin-transverse field interaction vanishes and, depending on the multipolar magnetic field order, the vortices can acquire different predictable topological charges. We explicitly demonstrate our findings, both numerically and analytically, by analyzing a 2D BEC via the Gross-Pitaevskii equation for atomic systems with either two or three internal states. We further show that, by an spontaneous symmetry breaking mechanism, vortices can appear in any spin component, unless symmetry is externally broken at the outset by an axial field. We suggest that this scenario may be tested using an ultracold gas of $^{87}$Rb occupying all three $F = 1$ states in an optical trap.