Josephson effect in thin films: The role of vortex excitations
Jetp Letters 85,1 (2007) 67-71;
We consider quantum slips of phase at a round hole punctured in a thin superconducting film and show that virtual vortex pairs provide an efficient pathway for these processes. Specifically, in the limit when the normal-state resistivity of the film is large, the presence of the film causes at most a logarithmic interaction between phase slips. This is in contrast to the nearly linear confining interaction (and the consequent nearly activated behavior of the resistance) obtained when vortices are neglected.
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