Theory of ac Josephson Effect in Superconducting Constrictions

Abstract

We have developed a microscopic theory of the ac Josephson effect within the general model of a high-transparency Josephson junction: short superconducting constriction with either ballistic or diffusive electron transport. Applications of the theory were studied, including smearing of the subgap current singularities by pair-breaking effects in the superconducting electrodes of the constriction, and the structure of these singularities in constrictions between the composite superconducting-normal electrodes with the proximity-induced gap in the normal layer.