EXCITATION-SPECTRA OF THE ANDERSON MODEL WITH CHARGE SCREENING THROUGH D-F COULOMB INTERACTION

Excitation spectra of the extended impurity Anderson model that includ es the intra-atomic d-f Coulomb screening are studied based on the num erical renormalization group method. The low-energy fixed point is usu ally classified as the local Fermi liquid state. There is a regime in which the single particle and the magnetic excitation spectra can be s caled by the effective Kondo temperature, T-K, which is reduced due to the screening effect. In this regime, the optical conductivity spectr um shows the excitonic shift in the energy region of the f --> d atomi clike transition, and the extreme increase of the intensity in the low -energy region comparable to T-K. In the valence fluctuation regime, t he coupled charge fluctuations of f and d electrons occur.