Multipolar ferroelectricity in the Mott regime

TL;DR

This paper investigates the origin of improper ferroelectricity in Mott insulators, highlighting the role of multipolar order and its transition from traditional mechanisms, which could reshape understanding of ferroelectric phenomena.

Contribution

It introduces a novel framework linking multipolar magnetic order to ferroelectricity in Mott insulators, extending beyond the traditional inverse Dzyaloshinskii-Moriya mechanism.

Findings

Transition from inverse Dzyaloshinskii-Moriya to multipolar ferroelectricity

Identification of intermediate regimes with mixed mechanisms

Potential to reexamine ferroelectricity in multipolar-ordered magnets

Abstract

Ferroelectricity has been one major focus in modern fundamental research and technological application. We consider the physical origin of improper ferroelectricity in Mott insulating materials. Beyond the well-known Katsura-Nagaosa-Balatsky's inverse Dzyaloshinskii-Moriya mechanism for the noncollinearly ordered magnets, we point out the induction of the electric polarizations in the multipolar ordered Mott insulators. Using the multiflavor representation for the multipolar magnetic moments, we can show the crossover or transition from the pure inverse Dzyaloshinskii-Moriya mechanism to the pure multipolar origin for the ferroelectricity, and also incorporate the intermediate regime with the mixture of both origins. We expect our results to inspire a reexamination of ferroelectricity in the multipolar-ordered magnets.