Key role of intramolecular Jahn-Teller vibrations and multivalley nature of the band spectrum in the mechanism of superconductivity in doped C60 fullerites

The possible mechanisms of superconductivity and of the increase in the critical temperature T-c of the phase transition into the superconducting state in doped cubic and hexagonal C-60 fullerine crystals are analyzed. It is shown that the intramolecular Jahn-Teller vibrations (which are due to the high symmetry of C-60 molecules and fullerene crystals and arise as a result of a change in the charge state of fullerene in an electron-phonon interaction), the degeneracy (multivalley nature) of the structure of narrow bands with a high density of states, and multiparticle Coulomb correlations such as local field effects (which increase the coupling constant in Cooper pariing of current carriers) all play a key role in the mechanism of superconductivity in this molecular metal. (C) 2002 American Institute of Physics.