Theoretical aspect on solid state device by ionic C60 superconductors

For ionic superconductors (C603−, C603+) in a field-effect transistor (FET), an extended BCS-like equation is presented in order to make clear the mechanism of such exotic superconductivity, and to apply to solid state device. Within the theory of phonon-mediated superconductivity, the possibility of higher transition temperature Tc and the role of various inter- and intramolecular phonons are discussed in comparison with bulk superconductivity in alkali-doped A3C60. Although ionic C603− and C603+ superconductors have two-dimensional structure in FET-device, it is indicated that the mechanism of superconductivity can be explained in a unified picture with three-dimensional bulk C60 superconductors (A3C60).