Resonating Valence Bonds and d Wave Superconductivity

Authors: Gabriel KOTLIAR

Abstract: The normal state and the superconducting properties of the cuprate superconductors continue to be a one of the most challenging problem in the theory of strongly correlated electron systems. In this talk I will review the results of early and recent mean field treatments of the Hubbard model in its large U limit, the t-J model, that capture many qualitative features of the experimentally observed phase diagram of the cuprates. The low temperature phase is a d wave superconductor, and the order parameter can have an admixture of an s component. At low doping the superconducting transition is controlled by phase fluctuations and a gap in the single particle spectrum opens above T_{c}. At large doping the superconducting transition temperature is determined by amplitude fluctuations.