Ferroelectricity induced by cooperative orbital ordering and Peierls instability

TL;DR

This paper proposes a general mechanism where orbital ordering coupled with Peierls distortions induces switchable ferroelectric polarization, analyzed through a Berry-phase approach, with potential applications to oxide spinels like CdV₂O₄.

Contribution

It introduces a novel theoretical framework linking orbital ordering and lattice distortions to ferroelectricity using Berry-phase analysis.

Findings

Mechanism explains switchable polarization in certain oxides

Berry-phase approach clarifies orbital contributions to ferroelectricity

Applicable to materials with one-dimensional electronic structures

Abstract

A general mechanism by which orbital ordering, coupled to Peierls-like lattice distortions, can induce an electronic switchable polarization is discussed within a model Hamiltonian approach in the context of the modern theory of polarization. By using a Berry-phase approach, a clear picture emerges in terms of Wannier-function centers and orbital occupancies. The proposed mechanism may apply to oxide spinels whose electronic structure has effective one-dimensional character, such as CdV$_2$O$_4$, recently proposed to display multiferroic behaviour.