Superconductivity in the Neighborhood of Metallic Contacts

Abstract

A microscopic theory of superconductivity in contact neighborhoods based on a modification of the parameter STAN(O)V! which occurs in the previously devised expression for the energy gap epsilon = 2(h omega )/sub a//sub v/exp(-- N(O)V) is presented. The arguments have as a converse the implication that the contact region of nonsuperconducting materials should become superconducting when in contact with superconductors. The effective penetration of electrons from one region to another is limited among other things by the electron mean free path; the further superconducting electrons penetrate into the normal area'' the smaller the energy gap should be. There should be only one transition temperature for an entire sample. (P.C.H.)