Scattering by impurity-induced order-parameter "holes" in d-wave superconductors

Nonmagnetic impurities in d-wave superconductors cause strong local suppres sions of the order parameter. We investigate the observable effects of the scattering of such suppressions in bulk samples by treating the order param eter "hole" as a pointlike off-diagonal scatterer heated within a self-cons istent t-matrix approximation. Strong scattering potentials lead to a finit e-energy spectral feature in the d-wave "impurity band," the observable eff ects of which include enhanced low-temperature microwave power absorption a nd a stronger sensitivity of the London penetration depth to disorder than found previously in simpler "dirty" d-wave models. [S0163-1829(99)03413-X].