Screening, Coulomb pseudopotential, and superconductivity in alkali-doped fullerenes.

Koch E., Gunnarsson O., Martin R.M.

We study the static screening in a Hubbard-like model using quantum Monte Carlo methods. We find that the random phase approximation is surprisingly accurate almost up to the Mott transition. We argue that in alkali-doped fullerenes the Coulomb pseudopotential mu * is not very much reduced by retardation effects. Therefore efficient screening is important in reducing mu * sufficiently to allow for an electron-phonon driven superconductivity. In this way the fullerides differ from the conventional picture, where retardation effects play a major role in reducing the electron-electron repulsion. 

A reprint of this paper can be obtained here.

Physical Review Letters, 83 620-3, 1999.

Max-Planck Institut für Festkörperforschung;

Postfach 80 06 65   D-70506 Stuttgart

      to publication list

     to Activities 1995-2000