Superflow in a Toroidal Bose-Einstein Condensate: An Atom Circuit with a Tunable Weak Link 论文

详细信息

发表期刊/会议

Physical Review Letters

发表日期

2011-03-28

发表年份

2011

摘要

We have created a long-lived (≈40 s) persistent current in a toroidal Bose-Einstein condensate held in an all-optical trap. A repulsive optical barrier across one side of the torus creates a tunable weak link in the condensate circuit, which can affect the current around the loop. Superflow stops abruptly at a barrier strength such that the local flow velocity at the barrier exceeds a critical velocity. The measured critical velocity is consistent with dissipation due to the creation of vortex-antivortex pairs. This system is the first realization of an elementary closed-loop atom circuit.