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arXiv · 2405.07405

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

Koki Nukui·Satoshi Iihama·Kazuaki Ishibashi·Shogo Yamashita·Akimasa Sakuma·Philippe Scheid·Grégory Malinowski·Michel Hehn·Stéphane Mangin·Shigemi Mizukami
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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.

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Koki Nukui, Satoshi Iihama, Kazuaki Ishibashi, Shogo Yamashita, Akimasa Sakuma, Philippe Scheid, Grégory Malinowski, Michel Hehn, Stéphane Mangin, Shigemi Mizukami. 2024-05-13. Light-induced torque in ferromagnetic metals via orbital angular momentum generated by photon-helicity. https://doi.org/10.1103/physrevlett.134.016701

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