Fluctuations and the superconducting phase transition: II. Onset of Josephson tunneling and paraconductivity of a junction

摘要: When one metallic film of a tunneling junction is in the superconducting state but other above its transition temperature, fluctuations pair field second cause instantaneous Josephson currents to flow. Application Kubo formula these current yields conductivity with strong temperature dependence, tending infinity at transition. The numerical magnitude this "paraconductivity" sufficiently large be observable for junctions very low normal resistance (and may possibly compared some recent measurements Lipsonet al.). High-frequency studies would determine directly relaxation rate. An experimental advantage paraconductivity that it not sensitive electron mean free path and therefore does require amorphous films.