Spin-orbit torques in locally and globally non-centrosymmetric crystals: antiferromagnets and ferromagnets

�elezn�, J.; Gao, H.; Manchon, Aurelien; Freimuth, Frank; Mokrousov, Yuriy; Zemen, J.; Ma�ek, J.; Sinova, Jairo; Jungwirth, T.

Abstract

One of the main obstacles that prevents practical applications of antiferromagnets is the dfficulty of manipulating the magnetic order parameter. Recently, following the theoretical prediction [J. Železný et al., PRL 113, 157201 (2014)], the electrical switching of magnetic moments in an antiferromagnet has been demonstrated [P. Wadley et al., Science 351, 587 (2016)]. The switching is due to the so-called spin-orbit torque, which has been extensively studied in ferromagnets. In this phenomena a non-equilibrium spin-polarization exchange coupled to the ordered local moments is induced by current, hence exerting a torque on the order parameter. Here we give a general systematic analysis of the symmetry of the spin-orbit torque in locally and globally non-centrosymmetric crystals. We study when the symmetry allows or a nonzero torque, when is the torque effective, and its dependence on the applied current direction and orientation of magnetic moments. For comparison, we consider both antiferromagnetic and ferromagnetic orders. In two representative model crystals we perform microscopic calculations of the spin-orbit torque to illustrate its symmetry properties and to highlight conditions under which the spin-orbit torque can be effcient for manipulating antiferromagnetic moments.

Citation

Železný, J., Gao, H., Manchon, A., Freimuth, F., Mokrousov, Y., Zemen, J., Mašek, J., Sinova, J., & Jungwirth, T. (2017). Spin-orbit torques in locally and globally non-centrosymmetric crystals: antiferromagnets and ferromagnets. Physical Review B, 95(1), Article 014403. https://doi.org/10.1103/PhysRevB.95.014403

• Journal Article Type: Article
• Acceptance Date: Dec 6, 2016
• Online Publication Date: Jan 5, 2017
• Publication Date: Jan 5, 2017
• Deposit Date: Jul 17, 2017
• Publicly Available Date: Jul 17, 2017
• Journal: Physical Review B
• Print ISSN: 2469-9950
• Electronic ISSN: 2469-9969
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 95
• Issue: 1
• Article Number: 014403
• DOI: https://doi.org/10.1103/PhysRevB.95.014403
• Public URL: https://nottingham-repository.worktribe.com/output/841860
• Publisher URL: https://journals.aps.org/prb/abstract/10.1103/PhysRevB.95.014403
• Contract Date: Jul 17, 2017