Superconductivity in hole-doped C60 from electronic correlations -: art. no. 180501

We derive a model for the highest occupied molecular-orbital band of a C-60 crystal which includes on-site electron-electron interactions. The form of the interactions are based on the icosahedral symmetry of the C-60 molecule together with a perturbative treatment of an isolated C-60 molecule. Using this model we do a mean-field calculation in two dimensions on the [100] surface of the crystal. Due to the multiband nature we find that the electron-electron interactions can have a profound effect on the density of states as a function of doping. The doping dependence of the transition temperature can then be qualitatively different from that expected from simple BCS theory based on the density of states from band structure calculations.