Nature of insulating state in the three-band hubbard model : a tight-binding approach

Abstract

We study the three-band Hubbard model, commonly used to describe the copper-oxygen planes of high-Tc superconductors, from the point of view of electronic properties. Utilizing perturbation theory around the atomic limit to evaluate finite-temperature Green's functions, one-particle densities of states are calculated in some simple approximations. Both metallic paramagnetic and insulating antiferromagnetic solutions are obtained, depending on the hole concentration. We discuss the overall scenario obtained here in comparison with experimental results and other theoretical approaches.