Kondo lattice model at half-filling

TL;DR

This paper investigates the Kondo lattice model at half-filling using dynamical mean field theory and exact diagonalization, revealing a phase transition in the two-channel case and confirming previous findings in the single-channel case.

Contribution

It applies dynamical mean field theory with exact diagonalization to study both single- and two-channel Kondo lattice models at half-filling, highlighting a symmetry breaking transition in the two-channel case.

Findings

Confirmed and extended results for the single-channel model.

Discovered a symmetry breaking phase transition in the two-channel model.

Performed calculations at low temperatures and large couplings.

Abstract

The single- and two-channel Kondo lattice model consisting of localized spins interacting antiferromagnetically with the itinerent electrons, are studied using dynamical mean field theory. As an impurity solver for the effective single impurity Anderson model we used the exact diagonalization (ED) method. Using ED allowed us to perform calculations for low temperatures and couplings of arbitrary large strength. Our results for the single-channel case confirm and extend the recent investigations. In the two-channel case we find a symmetry breaking phase transition with increasing coupling strength.