A Shiba-Rusinov theory for paramagnetic impurities in proximity effect sandwiches

Abstract

The Shiba-Rusinov theory, which takes into account both the potential and exchange interactions existing between a conduction electron and a paramagnetic impurity atom, is used to study the effects due to paramagnetic impurities dissolved in the normal layer of a proximity effect sandwich. Using a T-matrix approach to treat the interactions due to the impurities and the standard Born approximation to treat the other interactions in the sandwich, we obtain a set of self-consistent equations for the renormalized frequencies and the unrenormalized energy gaps for the electrons in both layers. The solutions of these equations are then used to obtain expressions for the decrease in the transition temperature of the sandwich and for the jump in the specific heat at Tc. © 1984 Plenum Publishing Corporation.