Light-induced torque in ferromagnetic metals via orbital angular momentum generated by photon-helicity

Abstract

We investigated photon-helicity-induced magnetization precession in Co${}_{1-x}$Pt${}_x$ alloy thin films. In addition to field-like torque, attributable to magnetic field generation owing to {\it the inverse Faraday effect}, we observed non-trivial and large damping-like torque which has never been discussed for single ferromagnetic layer. The composition dependence of those two torques is effectively elucidated by a model that considers mutual coupling via spin-orbit interaction between magnetization and the electronic orbital angular momentum generated by photon-helicity. This work significantly enhances our understanding of the physics relevant to the interplay of photon-helicity and magnetization in magnetic metals.

7 pages, 4 figures

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Cited by in corpus (3)

• Optical Switching of Moiré Chern Ferromagnet
• Light-induced Orbital and Spin Magnetism in $3d$, $4d$, and $5d$ Transition Metals
• Scattering makes a difference in circular dichroic angle-resolved photoemission