Optical Magnetoelectric Effect in Multiferroic Materials: Evidence for a Lorentz Force Acting on a Ray of Light

TL;DR

This paper theoretically demonstrates that in multiferroic materials like GaFeO₃, a Lorentz-force-like effect on light occurs due to the magnetoelectric effect, with the toroidal moment acting as a vector potential.

Contribution

It introduces a theoretical framework showing how the optical Lorentz force arises in multiferroics via the toroidal moment acting as a vector potential.

Findings

The optical Lorentz force can be realized in multiferroic materials.

The toroidal moment acts as a vector potential for light.

An estimate of the effect's magnitude is provided.

Abstract

We theoretically propose that the optical analog of a Lorentz force acting on a ray of light is realized in multiferroic materials such as GaFeO$_3$ showing the magnetoelectric effect. The toroidal moment plays the role of a ``vector potential" while its rotation corresponds to a "magnetic field" for photons. Hence, the light is subject to the Lorentz force when propagating through the domain wall region of the ferromagnetic or ferroelectric order. A realistic estimate on the magnitude of this effect is given.