Three-vortex configurations in trapped Bose-Einstein condensates

TL;DR

This paper demonstrates the creation and observation of three-vortex configurations in a Bose-Einstein condensate, revealing stable arrangements and providing experimental evidence for predicted vortex clusters.

Contribution

It introduces a method to generate various three-vortex configurations in BECs and identifies their stable arrangements, including the first experimental signatures of certain vortex clusters.

Findings

Creation of three-vortex clusters via oscillatory excitation

Identification of stable equilateral-triangle and linear vortex arrangements

Experimental evidence for predicted stationary vortex clusters

Abstract

We report on the creation of three-vortex clusters in a $^{87}Rb$ Bose-Einstein condensate by oscillatory excitation of the condensate. This procedure can create vortices of both circulation, so that we are able to create several types of vortex clusters using the same mechanism. The three-vortex configurations are dominated by two types, namely, an equilateral-triangle arrangement and a linear arrangement. We interpret these most stable configurations respectively as three vortices with the same circulation, and as a vortex-antivortex-vortex cluster. The linear configurations are very likely the first experimental signatures of predicted stationary vortex clusters.