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±0.6 nm.Received 9 June 2023Accepted 7 September 2023DOI:https://doi.org/10.1103/PhysRevLett.131.156702© 2023 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasSpintronicsPhysical SystemsThin filmsTechniquesDensity functional calculationsMagneto-optical Kerr effectCondensed Matter, Materials & Applied Physics