A SELF-CONSISTENT CLUSTER STUDY OF THE EMERY MODEL

We calculate Fermi-surface properties of the Cuprate superconductors w ithin the three-band Hubbard model (also called the Emery model) using a cluster expansion for the proper self-energy. The Fermi-surface top ology is in agreement with angular-resolved photoemission data for dop ings similar to 20%. We discuss possible violations of the Luttinger s um-rule for smaller dopings and the role of van-Hove singularities in the density of states of the Zhang-Rice singlets. We calculate the shi ft in the chemical potential upon doping and find quantitative agreeme nt with recent experiments.