Phase diagram of an extended Kondo lattice model for manganites: the Schwinger-boson mean-field approach

TL;DR

This paper uses the Schwinger-boson mean-field approach to explore the phase diagram of an extended Kondo lattice model for doped manganites, revealing the interplay of magnetic order, charge ordering, and phase separation influenced by electron correlations.

Contribution

It introduces a Schwinger-boson mean-field method to analyze the effects of strong Hund's coupling and Coulomb interaction on charge and magnetic phases in manganites.

Findings

Charge ordering and phase separation depend on electron interactions.

Strong Coulomb interaction influences magnetic and charge phases.

Finite Hund's coupling affects low-temperature charge distribution.

Abstract

We investigate the phase diagram of an extended Kondo lattice model for doped manganese oxides in the presence of strong but finite Hund's coupling and on-site Coulomb interaction. By means of the Schwinger-boson mean-field approach, it is found that, besides magnetic ordering, there will be non-uniform charge distributions, such as charge ordering and phase separation, if the interaction between electrons prevails over the hybridization. Which of the charge ordering and phase separation appears is determined by a competition between effective repulsive and attractive interactions due to virtual processes of electron hopping. Calculated results show that strong electron correlations caused by the on-site Coulomb interaction as well as the finite Hund's coupling play an important role in the magnetic ordering and charge distribution at low temperatures.