Thermodynamics of the half-filled Kondo lattice model around the atomic limit

TL;DR

This paper develops a perturbation theory to analyze thermodynamic properties of the half-filled Kondo lattice model in the atomic limit, applicable across various dimensions, revealing characteristic thermally activated behaviors and specific heat features.

Contribution

It introduces a perturbation approach for the Kondo lattice model's thermodynamics near the atomic limit, applicable in any dimension, and discusses extensions to the periodic Anderson model.

Findings

Chemical potential remains zero at all temperatures.

Spin and charge susceptibilities show thermally activated behavior.

Specific heat exhibits a two-peak structure.

Abstract

We present a perturbation theory for studying thermodynamic properties of the Kondo spin liquid phase of the half-filled Kondo lattice model. The grand partition function is derived to calculate chemical potential, spin and charge susceptibilities and specific heat. The treatment is applicable to the model with strong couplings in any dimensions (one, two and three dimensions). The chemical potential equals zero at any temperatures, satisfying the requirement of the particle-hole symmetry. Thermally activated behaviors of the spin(charge) susceptibility due to the spin(quasiparticle) gap can be seen and the two-peak structure of the specific heat is obtained. The same treatment to the periodic Anderson model around atomic limit is also briefly discussed.