Structural Transformation and Melting of the Vortex Lattice in the Rotating Bose Einstein Condensates

Abstract

AbstractWe numerically investigate the effect of the depth and lattice constant of square optical lattice on the vortex lattice structure of the rotating Bose-Einstein condensates. For a given angular velocity and lattice constant of the optical lattice, vortex lattice structure makes a transition from the hexagonal to the fully pinned square lattice upon increasing the pinning strength of the potential. A detailed quantitative analysis has been performed to understand the transition of the vortex lattice structure by changing the angular velocity, lattice constant and strength of the optical lattice potential. We find that the angular velocity at which the minimum potential strength is required to obtain fully pinned square vortex lattice increases upon decreasing the lattice constant of the potential with power law dependence. We also show the effect of random impurities along with pinning potential on the structure of the vortex lattice which triggers melting of the vortex lattice.KeywordsOptical latticeVorticesAbrikosov latticeRandom potential