Gap Inhomogeneities and the Density of States in Disorderedd-Wave Superconductors
W. A. Atkinson, P. J. Hirschfeld, Allan H. MacDonald
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.
arXiv:cond-mat/0002333•Physical Review Letters•Oct 30, 2000•75 citations