Transition temperature of two-band superconductors with Anderson impurities

Abstract

The influence of impurities on the superconducting transition temperature of two-band superconductors containing Anderson impurities is investigated. It is found that the concentration-dependent transition temperature shows typical departures from the formula for a single-band superconductor. These departures occur because of the interband scattering of conduction electrons on impurities. The calculations reveal clearly that in the presence of impurities the effective pairing interaction becomes coupling-parameter dependent, giving rise to a new pair-weakening mechanism. Analytic results for Tcon the basis of this simple two-band model are presented. © 1981 Plenum Publishing Corporation.