The effect of the exhaustion on the magnetic and optical properties of the periodic Anderson model

Abstract

We are interested in the study of the “exhaustion problem”, as originally introduced by Nozières, in the Kondo regime, and its manifestations on the magnetic and optical properties of the periodic Anderson model (PAM). In the case of the impurity problem there is only one single energy scale governed by the Kondo temperature T K , below which the local moment is screened by the conduction electrons. In the lattice case, there is the emergence of another energy scale governed by the coherence temperature T * , below which the system forms a Fermi liquid. The “exhaustion problem” becomes especially relevant when few conduction electrons n c ⪡ 1 are available to screen the local spins. To solve the model we employ the X-boson approach. We computed numerically the evolution of the magnetic susceptibility and the optical conductivity, in the heavy fermion Kondo-exhaustion regime, as a function of the temperature T, when the total occupation number N t was kept constant.