Dynamics of vortex lattice formation in a rotating Bose-Einstein condensate

We study the dynamics of vortex lattice formation of a rotating trapped Bose-Einstein condensate by numerically solving the two-dimensional Gross-Pitaevskii equation with a dissipative term. The condensate trapped in a quadratic potential forms a triangle lattice of quantized vortices, following the damped elliptic oscillation of the condensate and the excitation of surface waves, which is consistent with the experimental results of an ENS group. A fast rotating condensate confined in a quadratic-plus-quartic potential generates a giant vortex absorbing all phase defects into a single density hole, where a quasi-one-dimensional circular superflow is realized. (C) 2003 Elsevier Science B.V. All rights reserved.