Localization of strongly correlated electrons as Jahn-Teller polarons in manganites

TL;DR

This paper models manganites considering electron interactions and Jahn-Teller phonons, revealing that strong correlations lead to Jahn-Teller polarons and reproduce experimental magnetoresistance and spectra.

Contribution

It introduces a realistic model of manganites incorporating Coulomb, Hund's coupling, and Jahn-Teller effects, solved via dynamical mean field theory, to explain insulating behavior and magnetoresistance.

Findings

Large magnetoresistances observed in the model.

Spectra match experimental data.

Correlated electrons form Jahn-Teller polarons.

Abstract

A realistic modeling of manganites should include the Coulomb repulsion between $e_g$ electrons, the Hund's rule coupling to $t_{2g}$ spins, and Jahn-Teller phonons. Solving such a model by dynamical mean field theory, we report large magnetoresistances and spectra in good agreement with experiments. The physics of the unusual, insulating-like paramagnetic phase is determined by correlated electrons which are-due to strong correlations-easily trapped as Jahn-Teller polarons.