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arXiv · 1810.11003

First-principles calculation of spin-orbit torque in a Co/Pt bilayer

K. D. Belashchenko·Alexey A. Kovalev·M. van Schilfgaarde
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Abstract

The angular dependence of spin-orbit torque in a disordered Co/Pt bilayer is calculated using a first-principles non-equilibrium Green's function formalism with an explicit supercell averaging over Anderson disorder. In addition to the usual dampinglike and fieldlike terms, the odd torque contains a sizeable planar Hall-like term $(\mathbf{m\cdot E})\mathbf{m}\times(\mathbf{z}\times\mathbf{m})$ whose contribution to current-induced damping is consistent with experimental observations. The dampinglike and planar Hall-like torquances depend weakly on disorder strength, while the fieldlike torquance declines with increasing disorder. The torques that contribute to damping are almost entirely due to spin-orbit coupling on the Pt atoms, but the fieldlike torque does not require it.

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K. D. Belashchenko, Alexey A. Kovalev, M. van Schilfgaarde. 2018-10-25. First-principles calculation of spin-orbit torque in a Co/Pt bilayer. https://doi.org/10.1103/physrevmaterials.3.011401

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