Magnetic liquids under high electric fields as optical diodes

TL;DR

This paper demonstrates how magnetic liquids subjected to high electric fields can exhibit unidirectional light propagation due to the magnetoelectric effect, suggesting potential optical diode applications.

Contribution

It introduces the concept of one-way light propagation in magnetic fluids under specific electric and magnetic field conditions, a novel application of the magnetoelectric effect.

Findings

Unidirectional light propagation possible in magnetic fluids with nanoparticles.

Effective at nanoparticle diameters around 30 nm and concentrations above 2%.

Potential for optical diode development using magnetic liquids.

Abstract

We show and give examples of how unidirectional propagation of light rays in the limit of geometric optics could arise in some magnetic fluids due to the magnetoelectric effect under weak DC magnetic fields and strong DC electric fields around half of their dielectric breakdown. For such liquids as kerosene and transformer oils, one-way propagation of light may occur for 30 nm diameter magnetic nanoparticles (e.g. cobalt) and concentrations of 2% or larger.