Ferroelectricity due to orbital ordering in E-type undoped rare-earth manganites

TL;DR

This paper investigates how orbital ordering, driven by Jahn-Teller interactions, induces ferroelectricity in undoped E-type manganites through Berry phase calculations, revealing a significant electronic polarization contribution.

Contribution

It demonstrates that orbital ordering caused by Jahn-Teller coupling leads to ferroelectricity in undoped manganites, providing a microscopic understanding of the electronic polarization mechanism.

Findings

Finite polarization appears with strong Jahn-Teller coupling.

Orbital ordering is key to electronic ferroelectricity.

Supports large electronic polarization from first-principles predictions.

Abstract

Aiming at understanding the origin of the electronic contribution to ferroelectric polarization in undoped manganites, we evaluate the Berry phase of orbital-polarizable Bloch electrons as an orbital ordering (OO) establishes in the background of an antiferromagnetic E-type configuration. The onset of OO is tuned by the Jahn-Teller (JT) interaction in a tight-binding model for interacting electrons moving along zigzag chains. A finite polarization is found as soon as the JT coupling is strong enough to induce OO, supporting the large electronic contribution predicted from first principles.