Macroscopic angular-momentum states of Bose-Einstein condensates in toroidal traps

Abstract

We study the stability of a rotating repulsive-atom Bose-Einstein condensate in a toroidal trap. The resulting macroscopic angular-momentum states with integer vorticity l spread radially, lowering rotational energies. These states are robust against vorticity-lowering decays, with estimated metastability barriers capable of sustaining large angular momenta (l≲10) for typical parameters. We identify the centrifugally squashed l-dependent density profile as a possible signature of condensate rotation and superfluidity.