Symmetry of superconductivity in fullerides by repulsive interaction model

A repulsive interaction model for superconductivity (SC) in fullerides is studied using a second-order perturbation theory with respect to Coulomb repulsion. With the purely repulsive interaction, T-g and E-g pairs are the most stable in bcc and fcc lattices, respectively. In addition to anisotropic SC pairs, the s-wave (A(g)) pair can also be formed in both lattice models. Multiple Fermi surfaces in fullerides stabilize the A(g) pairs. We propose that the cooperation between Coulomb repulsion and electron-phonon interaction is responsible for the high T-c. (C) 2013 The Authors. Published by Elsevier B.V.