title: Gap inhomogeneities and the density of states in disordered d-wave superconductors
abstract: We report on a numerical study of disorder effects in 2D d-wave BCS superconductors. We compare exact numerical solutions of the Bogoliubov-de Gennes (BdG) equations for the density of states rho(E) with the standard T-matrix approximation. Local suppression of the order parameter near impurity sites, which occurs in self-consistent solutions of the BdG equations, leads to apparent power-law behavior rho(E) approximately |E|(alpha) with nonuniversal alpha over an energy scale comparable to the single-impurity resonance energy Omega(0). We show that the novel effects arise from static spatial correlations between the order parameter and the impurity distribution.
authors.affiliation: Department of Physics, University of Florida, P.O. Box 118440, Gainesville, Florida 32611, USA.
authors.initials: WA
authors.lastname: Atkinson
authors.initials: PJ
authors.lastname: Hirschfeld
authors.initials: AH
authors.lastname: MacDonald