Excitations of the ferroelectric order

TL;DR

This paper identifies and characterizes ferron excitations in ferroelectrics, revealing their unique properties and potential for tunable thermal and electric phenomena, based on a phenomenological theoretical approach.

Contribution

It introduces the concept of ferrons as longitudinal bosonic excitations in ferroelectrics and predicts their impact on various thermoelectric and electromechanical properties.

Findings

Ferrons are longitudinal excitations distinct from magnons.

Ferron spectrum predicts temperature-dependent pyroelectric and electrocaloric effects.

Ferron-photon hybridization enables new optoelectronic functionalities.

Abstract

We identify the bosonic excitations in ferroelectrics that carry electric dipoles from the phenomenological Landau-Ginzburg-Devonshire theory. The "ferron" quasi-particles emerge from the concerted action of anharmonicity and broken inversion symmetry. In contrast to magnons, the transverse excitations of the magnetic order, the ferrons in displacive ferroelectrics are longitudinal with respect to the ferroelectric order. Based on the ferron spectrum, we predict temperature dependent pyroelectric and electrocaloric properties, electric-field-tunable heat and polarization transport, and ferron-photon hybridization.