Observation of Vortex Pinning in Bose-Einstein Condensates

TL;DR

This paper reports the experimental observation of vortex pinning in rotating Bose-Einstein condensates, demonstrating how optical lattices can control vortex arrangements and induce structural transitions.

Contribution

It presents the first observation of vortex pinning in BECs using co-rotating optical lattices with different geometries, revealing orientation locking and lattice cross-over effects.

Findings

Vortices are pinned to optical lattice sites.

Orientation locking occurs between vortices and lattices.

Square lattices induce a structural cross-over in vortex arrangements.

Abstract

We report the observation of vortex pinning in rotating gaseous Bose-Einstein condensates (BEC). The vortices are pinned to columnar pinning sites created by a co-rotating optical lattice superimposed on the rotating BEC. We study the effects of two different types of optical lattice, triangular and square. With both geometries we see an orientation locking between the vortex and the optical lattices. At sufficient intensity the square optical lattice induces a structural cross-over in the vortex lattice.