THEORY OF AC JOSEPHSON EFFECT IN SUPERCONDUCTING CONSTRICTIONS

We have developed a microscopic theory of the ac Josephson effect with in the general model of a high-transparency Josephson junction: short superconducting constriction with either ballistic or diffusive electr on transport. Applications of the theory were studied, including smear ing of the subgap current singularities by pair-breaking effects in th e superconducting electrodes of the constriction, and the structure of these singularities in constrictions between the composite supercondu cting-normal electrodes with the proximity-induced gap in the normal l ayer.