Interaction between magnetic impurities in superconductors

Abstract

The Ruderman-Kittel theory of the interaction of magnetic impurities with each other is combined with Shiba's theory of the interaction between magnetic impurities and conduction electrons in superconductors. The result explains the experimental observation that, for a given ratio of the transition temperature of the alloy to that of the pure host metal, the effect of the impurity-impurity interaction is typically no larger for alloys with magnetic impurity concentration $n\approx 1$ at.% than for those in which $n$ is three orders of magnitude smaller.