Vortex stability of interacting Bose-Einstein condensates confined in anisotropic harmonic traps

Vortex states of weakly interacting Bose-Einstein condensates confined in t hree-dimensional rotating harmonic traps are investigated numerically at ze ro temperature. The ground state in the rotating frame is obtained by propa gating the Gross-Pitaevskii equation for the condensate in imaginary time. The total energies between states with and without a vortex are compared, y ielding critical rotation frequencies that depend on the anisotropy of the trap and the number of atoms. Vortices displaced from the center of nonrota ting traps are found to have long lifetimes for sufficiently large numbers of atoms. The relationship between vortex stability and bound core states i s explored.