Phonon spectral function for an interacting electron-phonon system.

Han J.E., Gunnarsson O.

Max-Planck-Institut für Festkörperforschung, Heisenbergstr. 1, D-70569 Stuttgart, Germany

Using exact diagonalization techniques, we study a model of interacting electrons and phonons. The spectral width of the phonons is found to be reduced as the Coulomb interaction U is increased. For a system with two modes per site, we find a transfer of coupling strength from the upper to the lower mode. This transfer is reduced as U is increased. These results give a qualitative explanation of differences between Raman and photoemission estimates of the electron-phonon coupling constants for A3C60 (A=K, Rb).

A reprint of this paper can be obtained in Germany or the US.


Physical Review B, 61 8628-30, 2000.

Max-Planck Institut für Festkörperforschung;
Postfach 80 06 65   D-70506 Stuttgart