Fermi surface and antiferromagnetism in the Kondo lattice: an asymptotically exact solution in d>1 Dimensions

TL;DR

This paper provides an asymptotically exact solution for the Kondo lattice model in dimensions greater than one, revealing the stability of antiferromagnetic phases with small Fermi surfaces and implications for heavy fermion quantum criticality.

Contribution

It introduces an asymptotically exact solution for the Kondo lattice model in d>1, showing the Kondo coupling is marginal and analyzing phase transitions in heavy fermion systems.

Findings

Kondo coupling is exactly marginal in the RG sense.

Existence of a stable antiferromagnetic phase with a small Fermi surface.

Implications for Lifshitz transitions and Kondo-destroying quantum critical points.

Abstract

Interest in the heavy fermion metals has motivated us to examine the quantum phases and their Fermi surfaces within the Kondo lattice model. We demonstrate that the model is soluble asymptotically exactly in any dimension d>1, when the Kondo coupling is small compared with the RKKY interaction and in the presence of antiferromagnetic ordering. We show that the Kondo coupling is exactly marginal in the renormalization group sense, establishing the stability of an ordered phase with a small Fermi surface, AFs. Our results have implications for the global phase diagram of the heavy fermion metals, suggesting a Lifshitz transition inside the antiferromagnetic region and providing a new perspective for a Kondo-destroying antiferromagnetic quantum critical point.