INFRARED CONDUCTIVITY OF A D(X(2)-Y(2))-WAVE SUPERCONDUCTOR WITH IMPURITY AND SPIN-FLUCTUATION SCATTERING

Calculations are presented of the in-plane far-infrared conductivity o f a d(x2-y2)-wave superconductor, incorporating elastic scattering due to impurities and inelastic scattering due to spin fluctuations. The impurity scattering is modeled by short-range potential scattering wit h arbitrary phase shift, while scattering due to spin fluctuations is calculated within a weak-coupling Hubbard model picture, The conductiv ity is characterized by a low-temperature residual Drude feature whose height and weight are controlled by impurity scattering, as well as a broad peak centered at 4 Delta(0) arising from clean-limit inelastic processes. Results are in qualitative agreement with experiment despit e missing spectral weight at high energies.