744 research outputs found
Fluctuations of the Josephson current and electron-electron interactions in superconducting weak links
We derive a microscopic effective action for superconducting contacts with
arbitrary transmission distribution of conducting channels. Provided
fluctuations of the Josephson phase remain sufficiently small our formalism
allows to fully describe fluctuation and interaction effects in such systems.
As compared to the well studied tunneling limit our analysis yields a number of
qualitatively new features which occur due to the presence of subgap Andreev
bound states in the system. We investigate the equilibrium supercurrent noise
and evaluate the electron-electron interaction correction to the Josephson
current across superconducting contacts. At T=0 this correction is found to
vanish for fully transparent contacts indicating the absence of Coulomb effects
in this limit.Comment: 12 pages, 4 figure
Triplet superconductivity in a ferromagnetic vortex
We argue that odd-frequency triplet superconductivity can be conveniently
realized in hybrid superconductor-ferromagnet (SF) structures with a
ferromagnetic vortex. We demonstrate that due to proximity-induced long-range
triplet pairing such SFS junctions can sustain appreciable supercurrent which
can be directly measured in experiments.Comment: 4 pages, 3 figure
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