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arXiv · 1511.03454

Spin Swapping Transport and Torques in Ultrathin Magnetic Bilayers

H. Saidaoui·A. Manchon
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Abstract

Planar spin transport in disordered ultrathin magnetic bilayers comprising a ferromagnet and a normal metal (typically used for spin pumping, spin Seebeck and spin-orbit torque experiments) is investigated theoretically. Using a tight-binding model that treats extrinsic spin Hall effect, spin swapping and spin relaxation on equal footing, we show that the nature of spin-orbit coupled transport dramatically depends on ratio between the layers thickness $d$ and the mean free path $λ$. While spin Hall effect dominates in the diffusive limit ($d\ggλ$), spin swapping dominates in Knudsen regime ($d\lesssimλ$). A remarkable consequence is that the symmetry of the spin-orbit torque exerted on the ferromagnet is entirely different in these two regimes.

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H. Saidaoui, A. Manchon. 2015-11-11. Spin Swapping Transport and Torques in Ultrathin Magnetic Bilayers. https://doi.org/10.1103/physrevlett.117.036601

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