d-wave nonadiabatic superconductivity
INFM Unitá di Roma 1 and Dipartimento di Fisica, Università di Roma 1 "La Sapienza", Piazzale A.
00185 Roma, Italy
2 École Polytechnique Fédérale de Lausanne, DMT-IPM, 1015 Lausanne, Switzerland
Published online: 15 September 2000
The inclusion of nonadiabatic corrections to the electron-phonon interaction leads to a strong momentum dependence in the generalized Eliashberg equations beyond Migdal's limit. For a s-wave symmetry of the order parameter, this induced momentum dependence leads to an enhancement of Tc when small momentum transfer is dominant. Here we study how the d-wave symmetry affects the above behavior. We find that the nonadiabatic corrections depend only weakly on the symmetry of the order parameter provided that only small momentum scatterings are allowed for the electron-phonon interaction. In this situation, We show that also for a d-wave symmetry of the order parameter, the nonadiabatic corrections enhance Tc. We also discuss the possible interplay and crossover between s- and d-wave depending on the material's parameters.
PACS: 63.20.Kr – Phonon-electron and phonon-phonon interactions / 71.38.+i – Polarons and electron-phonon interactions / 74.20.Mn – Nonconventional mechanisms
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2000