Physical Review Letters
We report the observation of vortex pinning in rotating gaseous Bose-Einstein condensates. Vortices are pinned to columnar pinning sites created by a corotating optical lattice superimposed on the rotating Bose-Einstein condensates. We study the effects of two types of optical lattice: triangular and square. In both geometries we see an orientation locking between the vortex and the optical lattices. At sufficient intensity the square optical lattice induces a structural crossover in the vortex lattice.
Tung, S.; Schweikhard, V.; and Cornell, Eric A., "Observation of Vortex Pinning in Bose-Einstein Condensates" (2006). Physics Faculty Contributions. 36.