The Kondo boson theory of the dynamic susceptibility of heavy fermions

Abstract

We apply the Kondo-boson - 1/ N expansion to the microscopic Anderson lattice model, properly generalized to include the effects of spin-orbit coupling. We compute the imaginary susceptibility for a generic cubic band structure including the effects of the leading order Fermi liquid interactions. We show that the antiferromagnetic correlations (at the zone boundary) which occur at frequencies of the order of the Kondo temperature, arise naturally as a consequence of transitions across the hybridization gap or the Fermi surface. Finite frequency structure at the zone center derives from f-spin non conserving interactions mediated by exchange of Kondo boson propagators. We discuss alternate “interacting impurities” approaches in light of the experimental evidence for coherence and a sharp Fermi surface at low temperatures.