Correlation effects associated to charge and spin fluctuations in s orbitals

M. A. ROMERO; E. C. GOLDBERG

Puerto Iguazú

Simposio; XIX Latin American Symposium on Solid State Physics (SLAFES); 2008

In this work we present a theoretical model to calculate the charge exchange between surfaces an atoms, in which we contemplate the correlated zero, one and two electron atomic configurations. An Anderson Hamiltonian written by using a projection technique is used for describing the atom-surface interaction. The appropriate Green functions are calculated with the motion equation method (EOM) closed up to a second order in the coupling parameter. Occupation probabilities and projected density of states on the atom are calculated for many different relations between the Coulomb repulsion and the coupling with the band states. Two limit cases: flat band approximation of the surface and the very discrete three-levels system are studied. In the last case, the comparison with exact results is possible. The high electron-hole symmetry case is also discussed.