Normal state phase of CuO planes in high Tc superconductors

Full text: We examine various aspects of the normal state phase of the copper oxide planes in high Tc superconductors. In particular, within the context of the three band Hubbard model, we study as a function of doping the competition between a charge density wave phase induced by the experimentally observed oxygen breathing modes, antiferromagnetic order, and paramagnetism. To account for the strong fermion interactions we use the finite U slave boson technique of Kotliar and Ruckenstein. Also, we discuss whether localisation of one hole per copper site is possible at finite doping in the paramagnetic phase. Here, we characterise localisation as a vanishing of the effective bandwidth. We obtain a metal insulator phase diagram at half filling