Details of disorder matter in 2D d-wave superconductors

Abstract

We demonstrate that discrepancies between predicted low-energy quasiparticle properties in disordered 2D d-wave superconductors occur because of the unanticipated importance of disorder model details and normal-state particle-hole symmetry. This conclusion follows from numerically exact evaluations of the quasiparticle density-of-states predicted by the Bogoliubov-deGennes (BdG) mean field equations for both binary alloy and random site energy disorder models. For the realistic case, which is best described by a binary alloy model without particle-hole symmetry, we predict density-of-states suppression below an energy scale which appears to be correlated with the corresponding single-impurity resonance.