Controlling of light with electromagnons

TL;DR

This paper explores how magnetoelectric coupling in multiferroic materials enables control over light propagation, highlighting effects like optical activity and asymmetric transmission near electromagnon resonances.

Contribution

It introduces a detailed analysis of optical activity and asymmetric propagation effects caused by electromagnons in multiferroic materials, expanding understanding of light control mechanisms.

Findings

Optical polarization rotation proportional to magnetoelectric susceptibility.

Asymmetric transmission with different forward and backward coefficients.

Strong effects observed near electromagnon resonance frequencies.

Abstract

Magnetoelectric coupling in multiferroic materials opens new routes to control the propagation of light. The new effects arise due to dynamic magnetoelectric susceptibility that cross-couples the electric and magnetic fields of light and modifies the solutions of Maxwell equations in media. In this paper two major effects will be considered in detail: optical activity and asymmetric propagation. In case of optical activity the polarization plane of the input radiation rotates by an angle proportional to the magnetoelectric susceptibility. The asymmetric propagation is a counter-intuitive phenomenon and it represents different transmission coefficients for forward and backward directions. Both effects are especially strong close to resonance frequencies of electromagnons, i.e. excitations in multiferroic materials that reveal simultaneous electric and magnetic character.