Eur. Phys. J. B 17, 235-243 (2000)
https://doi.org/10.1007/s100510070137

d-wave nonadiabatic superconductivity

¹ INFM Unitá di Roma 1 and Dipartimento di Fisica, Università di Roma 1 "La Sapienza", Piazzale A. Moro 2, 00185 Roma, Italy
² École Polytechnique Fédérale de Lausanne, DMT-IPM, 1015 Lausanne, Switzerland

Received: 12 May 2000
Published online: 15 September 2000

Abstract

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 T_c 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 T_c. We also discuss the possible interplay and crossover between s- and d-wave depending on the material's parameters.