Creation of persistent current and vortex in a Bose-Einstein condensate of alkali-metal atoms

TL;DR

This paper theoretically demonstrates how persistent currents and vortices can be created and observed in a Bose-Einstein condensate of alkali-metal atoms, highlighting the role of spin degrees of freedom.

Contribution

It introduces a method to generate persistent currents in BECs using spin degrees of freedom and analyzes their transformation into vortices and relaxation dynamics.

Findings

Persistent currents can be created in BECs via spin manipulation.

Persistent currents can be transformed into vortices.

Relaxation dynamics reflect the presence of persistent currents.

Abstract

It is shown theoretically that a persistent current can be continuously created in a Bose-Einstein condensate (BEC) of alkali atoms confined in a multiply connected region by making use of a spin-degree of freedom of the order parameter of a BEC. We demonstrate that this persistent current is easily transformed into a vortex. Relaxation processes of these BEC after the confining field is turned off are also studied so that our analyses are compared with time of flight experiments. The results are shown to clearly reflect the existence of a persistent current.