Local and band approaches to actinide systems

Abstract

We investigate two models of interest in the context of actinide and rare earth systems. We extend previous work on the Anderson model for two magnetic configurations and obtain the singlet quasiparticle energy to next leading order in the expansion. We prove that the appropriate Ward identity and perturbative scaling results are reproduced in this theory. We also prove the opposite limit in which there is significant f-f overlap using the infinite U Hubbard model. Working to second order in the expansion, we study the quasiparticle scattering amplitudes and find a large enhancement in the Landau parameter [function of (italic small f)]a0 near half filling which varies as the cube of the mass enhancement. For a free-electron-like dispersion relation, this implies a transition to a ferromagnetic state for small hole concentrations.