All-Optical Generation of Antiferromagnetic Magnon Currents via the Magnon Circular Photogalvanic Effect

TL;DR

This paper demonstrates an all-optical method to generate directed magnon currents in honeycomb antiferromagnetic insulators using circularly polarized light, leveraging the magnon circular photogalvanic effect via stimulated Raman scattering.

Contribution

It introduces the magnon circular photogalvanic effect as a new all-optical mechanism for magnon current generation in antiferromagnets, with control via laser polarization and incidence angle.

Findings

Magnon currents can be generated using circularly polarized light.

The effect is the dominant contribution to magnon photocurrent generation.

Detection via inverse spin Hall voltages in platinum is feasible.

Abstract

We introduce the magnon circular photogalvanic effect enabled by stimulated Raman scattering. This provides an all-optical pathway to the generation of directed magnon currents with circularly polarized light in honeycomb antiferromagnetic insulators. The effect is the leading order contribution to magnon photocurrent generation via optical fields. Control of the magnon current by the polarization and angle of incidence of the laser is demonstrated. Experimental detection by sizeable inverse spin Hall voltages in platinum contacts is proposed.