Microwave conductivity of<i>d</i>-wave superconductors

Abstract

We calculate the microwave conductivity of a ${\mathit{d}}_{\mathit{x}}^{2}$-${\mathit{y}}^{2}$ superconductor in the presence of elastic impurity scattering and inelastic scattering due to antiferromagnetic spin fluctuations. The low-temperature conductivity does not simply reflect the linear temperature dependence of the number of quasiparticles in a d-wave system, as often supposed. We compare with recent data on high-quality ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{6.95}$ single crystals.