Fullerenes and carbon derivatives: from insulators to superconductors

This review is focused on the discussion of the optical properties of various fullerene derivatives. The main emphasis will be devoted to the alkali-metal-doped superconducting fullerenes (A(3)C(60)) and the linear polymers (AC(60)), With A = K, Rb or Cs. The electrodynamic response will reveal important information about the normal-state properties and the nature of the superconducting and broken-symmetry ground state of these fullerene derivatives. Moreover, the discussion of the optical data will permit us to establish a global comparison with the experimental and theoretical state of the art on fullerene materials.