Critical temperature with paramagnetic and normal impurities under the square well model

Abstract

In the past, it has been shown that in superconductors where paramagnetic impurities are not involved, the results obtained from an analysis in the Eliashberg model with a square well approximation to the electron–phonon interaction are related simply to the analogous results of the Bardeen–Cooper–Schrieffer (BCS) model. The relation consists of a substitution of the mean square energy gap anisotropy for the mean square pairing potential anisotropy and of adding a (1 + λ) mass renormalization factor. The present paper considers a paramagnetic case in the same model and it is found that the relation to the BCS result is different from that of previously studied cases.