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arXiv · 1101.0019

Superflow in a toroidal Bose-Einstein condensate: an atom circuit with a tunable weak link

A. Ramanathan·K. C. Wright·S. R. Muniz·M. Zelan·W. T. Hill III·C. J. Lobb·K. Helmerson·W. D. Phillips·G. K. Campbell
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Abstract

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 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 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.

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A. Ramanathan, K. C. Wright, S. R. Muniz, M. Zelan, W. T. Hill III, C. J. Lobb, K. Helmerson, W. D. Phillips, G. K. Campbell. 2011-02-02. Superflow in a toroidal Bose-Einstein condensate: an atom circuit with a tunable weak link. https://doi.org/10.1103/physrevlett.106.130401

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