The Kondo-Hubbard model at half-filling

TL;DR

This paper investigates the magnetic and charge properties of the half-filled Kondo-Hubbard lattice across various band shapes and dimensions using a strong coupling perturbative approach, providing insights into elementary excitations and correlations.

Contribution

It introduces a perturbative method applicable to any band shape and dimension for analyzing the Kondo-Hubbard model at half-filling, including both antiferromagnetic and ferromagnetic cases.

Findings

Calculated energies of charge and spin excitations.

Characterized magnetic correlations at half-filling.

Linked ferromagnetic case to an effective antiferromagnetic model.

Abstract

We have analyzed the antiferromagnetic (J>0) Kondo-Hubbard lattice with the band at half-filling by means of a perturbative approach in the strong coupling limit, the small parameter is an arbitrary tight-binding band. The results are valid for any band shape and any dimension. We have obtained the energies of elementary charge and spin excitations as well as the magnetic correlations in order to elucidate the magnetic and charge behavior of the Kondo lattice at half-filling. Finally, we have briefly analyzed the ferromagnetic case (J<0), which is shown to be equivalent to an effective antiferromagnetic Heisenberg model.