Charge Fluctuations and Superconductivity in an Extended Periodic Anderson Model: A Weak Coupling Theory

Abstract

An extended periodic Anderson model, a model where repulsive interaction between an f -electron and a conduction electron is considered in addition to repulsive interaction between f -electrons, on a square lattice is studied with the fluctuation exchange approximation. It is found that charge susceptibilities at q =(π,π) are enhanced as the f -electron level ε f becomes shallow, implying the tendency towards a charge density wave instability. The effective attractive interaction leading to superconductivity is then calculated, and is shown to depend on ε f nonmonotonically.