Superconducting nucleation fields and proximity effect of normal-superconducting-normal triple layers

Abstract

Superconducting nucleation fields for normal-superconducting-normal (nsn) triple layers are calculated when the static magnetic field is applied parallel to thens boundaries, thes layer is of arbitrary thickness, and then metals are identical and very thick. Comparing these results with experiments by Jain and Tilley on Cu-Pb-Cu triple layers, one finds that Zaitsev's microscopicns boundary conditions apply (at least approximately) over a wide range of temperatures at the nucleation field. This implies thatpFδG is continuous across ans boundary for diffuse and δG for specular electron scattering (δG is the Gor'kov pair potential, pF the Fermi momentum). Furthermore, the magnitudes of the order parameters on thens boundary are similar for Cu and Pb over a wide range of temperatures in large magnetic fields.