Persistent currents in Bose gases confined in annular traps

We examine the problem of stability of persistent currents in a mixture of two Bose gases trapped in an annular potential. We evaluate the critical coupling for metastability in the transition from quasi-one- to two-dimensional motion. We also evaluate the critical coupling for metastability in a mixture of two species as a function of the population imbalance. The stability of the currents is shown to be sensitive to the deviation from one-dimensional motion.