We calculate the optical conductivity $\sigma \left(\omega \right)$ in the normal-state fullerene superconductors by self-consistently including the impurity scatterings, the electron-phonon, and electron-electron Coulomb interactions. The finite bandwidth of the fullerenes and the vertex corrections are explicitly considered in calculating the renormalized Green’s function. $\sigma \left(\omega \right)$ is obtained by calculating the current-current correlation function with the renormalized Green’s function in the Matsubara frequency and then performing analytic continuation to the real frequency at finite temperature. The Drude weight in $\sigma \left(\omega \right)$ is strongly suppressed due to the interactions and transfered to the mid-infrared region around and above $0.06\mathrm{eV},$ which is somewhat less pronounced and much broader compared with the experimental observation by DeGiorgi et al.

• Received 7 March 2000

DOI:https://doi.org/10.1103/PhysRevB.62.4440