Driving phase slips in a neutral-atom analog of an RF SQUID

We can deterministically control the quantized circulation state of a toroidal atomic Bose-Einstein condensate by rotating a weak link around the ring above a critical velocity. We vary this critical velocity by controlling the strength of the repulsive optical dipole potential creating the weak link. This system is directly analogous to a superconducting loop in an external magnetic field, where the loop is interrupted by a weak link with a dynamically tunable current-phase relation.