Superconducting state in the twofold degenerate Anderson impurity model

Abstract

The twofold degenerated Anderson impurity model in superconducting state is investigated and the strong electronic correlations of impurity ion are taken into account by elaborating suitable diagram technique. We obtain the Dyson type equations between impurity electron propagators and normal and anomalous correlation functions and by summing infinite series of ladder diagrams have established the approximation for correlation functions. Criterion for appearance of superconducting state of the model is discussed.