One particle spectral densities for the CuO 2 planes of high Tc superconductors

Abstract

We calculate numerically the one particle spectral densities for a small cluster of CuO 2 including intra and interatomic correlations. We show that the stoichiometric system with one hole per unit cell is a charge transfer insulator. The XPS spectra is calculated for this stoichiometric situation and for system doped with electrons or holes. Our results indicate that electron doping produces in the XPS spectrum a large peak at the Fermi energy.