Proximity effect sandwiches containing nonmagnetic localized states

Abstract

The effects of resonant scattering by nonmagnetic localized states in the normal layer on the critical temperatures of proximity effect sandwiches are studied through the renormalization of the electron propagators in the McMillan proximity effect model. By treating both the resonant scattering of the normal layer electrons and the Coulomb correlation between electrons of opposite spins located on the same impurity site self-consistently, an expression for the decrease in the critical temperature that shows explicitly the dependences on the parameters that describe the impurity atoms is obtained. The decrease in the critical temperatures as a function of impurity concentration and of normal layer thickness is shown. © 1984 Plenum Publishing Corporation.