Vortices in Bose-Einstein condensates confined in a multiply connected Laguerre-Gaussian optical trap

The quantized vortex state is investigated in a Bose-Einstein condensate, confined in a multiply connected geometry formed by a Laguerre-Gaussian optical trap. Solving the Gross-Pitaevskii equation variationally, we show that the criterium for vortex stability is that the interatomic interaction strength must exceed a critical interaction strength. The time evolution of a freely expanding Laguerre-Gaussian condensate with a vortex is calculated, and used to derive the interference pattern of such a condensate overlapping with a parabolically trapped condensate.