Charge order in Kondo lattice systems

TL;DR

This paper demonstrates that in heavy fermion systems at quarter filling, charge order can emerge solely from local interactions driven by the Kondo effect, challenging the traditional view that inter-site Coulomb repulsion is necessary.

Contribution

The study shows that local interactions and the Kondo effect alone can induce charge order in Kondo lattice systems at quarter filling, using dynamical mean field theory and numerical renormalization group.

Findings

Charge order occurs at quarter filling due to local interactions.

The Kondo effect drives the charge order formation.

Charge order is demonstrated through numerical simulations.

Abstract

Charge order is a commonly observed phenomenon in strongly correlated materials. However, most theories are based on a repulsive inter-site Coulomb interaction in order to explain charge order. We here show that only due to local interactions, charge order is favorable in heavy fermion systems at quarter filling. The driving force is the Kondo effect, which leads to a non-linear dependence on the filling of the lattice site for the energy gain. We use dynamical mean field theory combined with numerical renormalization group to demonstrate the existence of charge order at quarter filling for a Kondo lattice model.