Magneto-Optical Detection of the Orbital Hall Effect in Chromium

The orbital Hall effect has been theoretically predicted but its direct observation is a challenge. Here, we report the magneto-optical detection of current-induced orbital accumulation at the surface of a light 3d transition metal, Cr. The orbital polarization is in-plane, transverse to the current direction, and scales linearly with current density, consistent with the orbital Hall effect. Comparing the thickness-dependent magneto-optical measurements with ab initio calculations, we estimate an orbital diffusion length in Cr of 6.6 +/- 0.6nm.

Automated summary

This study reports the direct observation of current-induced orbital accumulation on the surface of a light 3d transition metal, Cr, using magneto-optical detection. The orbital polarization is transverse to the current direction and scales linearly with current density, consistent with the orbital Hall effect.