Berry's Phase Induced Bose-Einstein condensation into a Vortex State

Abstract

The existence of a geometric phase in magnetic traps can be used to Bose condense a magnetically trapped atomic gas into a vortex state. We propose an experimental setup where a magnetic trap together with a blue detuned laser beam form a multiply connected trap geometry. The local variation of the magnetic quantization axis induces a geometric or Berry's phase that allows the atoms to acquire an effective gauge charge interacting with the analog of a magnetic solenoid. It is shown that the ground state of such a system may be given by a vortex state. We also discuss the influence of atomic interactions on the proposed vortex production scheme in the context of present Bose-Einstein condensation experiments with dilute gases.