Charge and spin inhomogeneous phases in the Ferromagnetic Kondo Lattice Model

TL;DR

This paper investigates the one-dimensional ferromagnetic Kondo lattice model, revealing charge and spin inhomogeneous phases, magnetic polarons, and an insulator-metal transition driven by magnetic fields, relevant for nickel and manganese perovskites.

Contribution

It provides a detailed numerical analysis of charge and spin inhomogeneities and phase transitions in the ferromagnetic Kondo lattice model, highlighting the role of magnetic polarons.

Findings

Charge-ordered states form due to magnetic polarons.

An insulating gap is associated with charge structure formation.

Magnetic field induces an insulator-metal transition by removing charge and spin order.

Abstract

We study numerically the one-dimensional ferromagnetic Kondo lattice. This model is widely used to describe nickel and manganese perovskites. Due to the competition between double and super-exchange, we find a region where the formation of magnetic polarons induces a charge-ordered state. This ordering is present even in the absence of any inter-site Coulomb repulsion. There is an insulating gap associated to the charge structure formation. We also study the insulator-metal transition induced by a magnetic field which removes simultaneously both charge and spin ordering.