Impurity scattering in d+s wave superconductivity

¹ Physique des Solides, Université Paris-Sud - 91405 Orsay, France
² Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089-0484, USA

Received: 4 October 1995
Accepted: 15 December 1995

Abstract

We study non-magnetic impurity effects on a two-dimensional d+s model which we have introduced earlier to account for orthorhombicity in high-T_c compounds. T_c decreases when the impurity concentration increases similarly to the d model, except for the appearance of a small tail near the critical concentration where . But, in sharp contrast, in the same region, the density of states at the Fermi energy shows that an energy gap opens up, indicating a tendency for the d+s model to become more s -like; this should be accessible by specific-heat or NMR experiments.