Optical phonon attenuation in d-wave superconductors

Attenuation of longitudinal and transverse optical phonons in d-wave superconductors due to the electron-phonon interaction is calculated by employing the Kubo method. The electron-phonon interaction is considered in the frame of reference moving together with the lattice that allows us to exclude from consideration the inelastic electron-impurity scattering. The attenuation coefficient is calculated in the unitary limit and in the Born approximation for the electron-impurity scattering. It is found that the value and temperature dependence of the attenuation coefficient are strongly dependent on the value of the electron-impurity potential which can explain the observed sensitivity of experimental data to the sample quality. (C) 1999 Elsevier Science B.V. All rights reserved.