Theoretical Description of Pseudocubic Manganites

TL;DR

This paper develops a detailed theoretical model for bulk manganites, capturing key interactions and distortions, and successfully reproduces their phase diagram, providing a foundation for future complex calculations.

Contribution

It introduces a comprehensive theoretical framework for manganites that includes Jahn-Teller distortions and Coulomb interactions, solved via dynamical mean field theory.

Findings

Model semi-quantitatively matches observed phase diagram.

Manganites are in the strong coupling regime near Mott transition.

Framework applicable to heterostructure calculations.

Abstract

A comprehensive theoretical model for the bulk manganite system La$_{1-x}$(Ca,Sr)$_x$MnO$_3$ is presented. The model includes local and cooperative Jahn-Teller distortions and the on-site Coulomb and exchange interaction. The model is is solved in the single-site dynamical mean field approximation using a solver based on the semiclassical approximation. The model semi-quantitatively reproduces the observed phase diagram for the doping $0 \leq x<0.5$ and implies that the manganites are in the strong coupling region but close to Mott insulator/metal phase boundary. The results establish a formalism for use in a broader range of calculations, for example on heterostructures.