Ferroelectric Phase Transitions in a Lattice Pseudo-Jahn-Teller Model

TL;DR

This paper investigates ferroelectric phase transitions using a lattice pseudo-Jahn-Teller model analyzed through mean-field theory, revealing conditions for ferroelectric or antiferroelectric ground states based on coupling strength.

Contribution

It introduces a lattice generalization of a pseudo-Jahn-Teller model and analyzes its phase transitions, highlighting the emergence of ferroelectric and antiferroelectric states.

Findings

Ferroelectric or antiferroelectric ground states occur at strong pseudo-Jahn-Teller coupling.

Mean-field theory effectively predicts phase transitions in the model.

The model extends understanding of lattice-induced ferroelectricity.

Abstract

A lattice generalization of the $(b_{1u}\oplus b_{2g})\otimes b_{3u}$ pseudo-Jahn-Teller model is analyzed within mean-field theory. Ferroelectric or antiferroelectric ground states are found for sufficiently large pseudo-Jahn-Teller coupling.