Bipolaron anisotropic flat bands, Hall mobility edge, and metal-semiconductor duality of overdoped high-Tc oxides

Hole bipolaron band structure with two flat anisotropic bands is derived for oxide superconductors. Strong anisotropy leads to one-dimensional localization in a random field which explains the metal-like value of the Hall effect and the semiconductorlike doping dependence of resistivity of overdoped oxides. Doping dependence of Tc and λH(0) as well as the low-temperature dependence of resistivity, of the Hall effect, Hc2(T) and robust features of angle-resolved photoemission spectroscopy of several high-Tc copper oxides are explained.