Spin-orbit torque in a three-dimensional topological insulator–ferromagnet heterostructure: Crossover between bulk and surface transport
Type
ArticleAuthors
Ghosh, SumitManchon, Aurelien

KAUST Department
Material Science and Engineering ProgramPhysical Science and Engineering (PSE) Division
Spintronics Theory Group
Date
2018-04-02Permanent link to this record
http://hdl.handle.net/10754/627571
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Current-driven spin-orbit torques are investigated in a heterostructure composed of a ferromagnet deposited on top of a three-dimensional topological insulator using the linear response formalism. We develop a tight-binding model of the heterostructure adopting a minimal interfacial hybridization scheme that promotes induced magnetic exchange on the topological surface states, as well as induced Rashba-like spin-orbit coupling in the ferromagnet. Therefore our model accounts for the spin Hall effect from bulk states together with inverse spin galvanic and magnetoelectric effects at the interface on equal footing. By varying the transport energy across the band structure, we uncover a crossover from surface-dominated to bulk-dominated transport regimes. We show that the spin density profile and the nature of the spin-orbit torques differ substantially in both regimes. Our results, which compare favorably with experimental observations, demonstrate that the large dampinglike torque reported recently is more likely attributed to the Berry curvature of interfacial states, while spin Hall torque remains small even in the bulk-dominated regime.Citation
Ghosh S, Manchon A (2018) Spin-orbit torque in a three-dimensional topological insulator–ferromagnet heterostructure: Crossover between bulk and surface transport. Physical Review B 97. Available: http://dx.doi.org/10.1103/PhysRevB.97.134402.Sponsors
This work was supported by the King Abdullah University of Science and Technology (KAUST). The authors would like to acknowledge support from KAUST Supercomputing facility.Publisher
American Physical Society (APS)Journal
Physical Review BAdditional Links
https://journals.aps.org/prb/abstract/10.1103/PhysRevB.97.134402ae974a485f413a2113503eed53cd6c53
10.1103/PhysRevB.97.134402