EDGE TUNNELING OF VORTICES IN SUPERCONDUCTING THIN-FILMS

We investigate the phenomenon of the decay of a supercurrent due to th e zero-temperature quantum tunneling of vortices from the edge in a th in superconducting film in the absence of an external magnetic field. An explicit formula is derived for the tunneling rate of vortices, whi ch are subject to the Magnus force induced by the supercurrent, throug h the Coulomb-like potential barrier binding them to the film's edge. Our approach ensues from the nonrelativistic version of a Schwinger-ty pe calculation for the decay of the two-dimensional vacuum previously employed for describing vortex-antivortex pair nucleation in the bulk of the sample. in the dissipation-dominate limit, our explicit edge-tu nneling formula yields numerical estimates which are compared with tho se obtained for bulk nucleation to show that both mechanisms are possi ble for the decay of a supercurrent.