Vortex dynamics in a parabolically confined Bose-Einstein condensate

A path-integral technique for the calculation of the dynamics of parabolica lly confined Bose gases is presented. This method is applied to find the ti me evolution of a Bose-Einstein condensate containing a vortex. We find tha t the vortex core rotates around the centre of the trapping potential, keep ing the distance between the vortex core and the centre of the confinement potential constant, in agreement with recent experimental observations. The theoretically calculated period of this rotation (805 +/- 10 ms) agrees wi th the experimentally observed period (800 +/- 50 ms). (C) 2000 Elsevier Sc ience Ltd. All rights reserved.