Vortex Formation by Interference of Multiple Trapped Bose-Einstein Condensates

TL;DR

This paper investigates vortex formation in merging multiple Bose-Einstein condensates, revealing interference effects and phase dynamics as key factors in vortex generation during condensate merging.

Contribution

It demonstrates vortex formation resulting from interference of independently prepared BECs and highlights the role of phase indeterminacy and merging rate.

Findings

Vortices form during merging of independent BECs.

Interference between condensates causes vortex creation.

Vortex probability depends on phase and merging dynamics.

Abstract

We report observations of vortex formation as a result of merging together multiple $^{87}$Rb Bose-Einstein condensates (BECs) in a confining potential. In this experiment, a trapping potential is partitioned into three sections by a barrier, enabling the simultaneous formation of three independent, uncorrelated condensates. The three condensates then merge together into one BEC, either by removal of the barrier, or during the final stages of evaporative cooling if the barrier energy is low enough; both processes can naturally produce vortices within the trapped BEC. We interpret the vortex formation mechanism as originating in interference between the initially independent condensates, with indeterminate relative phases between the three initial condensates and the condensate merging rate playing critical roles in the probability of observing vortices in the final, single BEC.