title: Driving phase slips in a superfluid atom circuit with a rotating weak link.
abstract: We have observed well-defined phase slips between quantized persistent current states around a toroidal atomic (23Na) Bose-Einstein condensate. These phase slips are induced by a weak link (a localized region of reduced superfluid density) rotated slowly around the ring. This is analogous to the behavior of a superconducting loop with a weak link in the presence of an external magnetic field. When the weak link is rotated more rapidly, well-defined phase slips no longer occur, and vortices enter into the bulk of the condensate. A noteworthy feature of this system is the ability to dynamically vary the current-phase relation of the weak link, a feature which is difficult to implement in superconducting or superfluid helium circuits.
authors: National Institute of Standards and Technology and University of Maryland, Gaithersburg, Maryland 20899, USA.
authors: K C
authors: KC
authors: Wright
authors: R B
authors: RB
authors: Blakestad
authors: C J
authors: CJ
authors: Lobb
authors: W D
authors: WD
authors: Phillips
authors: G K
authors: GK
authors: Campbell