Spin-torque generation in topological insulator based heterostructures

Handle URI:
http://hdl.handle.net/10754/603505
Title:
Spin-torque generation in topological insulator based heterostructures
Authors:
Fischer, Mark H.; Vaezi, Abolhassan; Manchon, Aurelien ( 0000-0002-4768-293X ) ; Kim, Eun-Ah
Abstract:
Heterostructures utilizing topological insulators exhibit a remarkable spin-torque efficiency. However, the exact origin of the strong torque, in particular whether it stems from the spin-momentum locking of the topological surface states or rather from spin-Hall physics of the topological-insulator bulk, remains unclear. Here, we explore a mechanism of spin-torque generation purely based on the topological surface states. We consider topological-insulator-based bilayers involving ferromagnetic metal (TI/FM) and magnetically doped topological insulators (TI/mdTI), respectively. By ascribing the key theoretical differences between the two setups to location and number of active surface states, we describe both setups within the same framework of spin diffusion of the nonequilibrium spin density of the topological surface states. For the TI/FM bilayer, we find large spin-torque efficiencies of roughly equal magnitude for both in-plane and out-of-plane spin torques. For the TI/mdTI bilayer, we elucidate the dominance of the spin-transfer-like torque. However, we cannot explain the orders of magnitude enhancement reported. Nevertheless, our model gives an intuitive picture of spin-torque generation in topological-insulator-based bilayers and provides theoretical constraints on spin-torque generation due to topological surface states.
KAUST Department:
Physical Sciences and Engineering (PSE) Division
Citation:
Spin-torque generation in topological insulator based heterostructures 2016, 93 (12) Physical Review B
Publisher:
American Physical Society (APS)
Journal:
Physical Review B
Issue Date:
11-Mar-2016
DOI:
10.1103/PhysRevB.93.125303
Type:
Article
ISSN:
2469-9950; 2469-9969
Sponsors:
The authors are grateful to A. Mellnik and D. Ralph for helpful discussions.M.H.F. and E.-A.K. acknowledge support from NSF Grant No. DMR-0955822 and from NSF Grant No. DMR-1120296 to the Cornell Center for Materials Research. M.H.F. further acknowledges the Swiss Society of Friends of the Weizmann Institute of Science. A.M. was supported by the King Abdullah University of Science and Technology (KAUST).
Additional Links:
http://link.aps.org/doi/10.1103/PhysRevB.93.125303
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorFischer, Mark H.en
dc.contributor.authorVaezi, Abolhassanen
dc.contributor.authorManchon, Aurelienen
dc.contributor.authorKim, Eun-Ahen
dc.date.accessioned2016-03-22T13:52:44Zen
dc.date.available2016-03-22T13:52:44Zen
dc.date.issued2016-03-11en
dc.identifier.citationSpin-torque generation in topological insulator based heterostructures 2016, 93 (12) Physical Review Ben
dc.identifier.issn2469-9950en
dc.identifier.issn2469-9969en
dc.identifier.doi10.1103/PhysRevB.93.125303en
dc.identifier.urihttp://hdl.handle.net/10754/603505en
dc.description.abstractHeterostructures utilizing topological insulators exhibit a remarkable spin-torque efficiency. However, the exact origin of the strong torque, in particular whether it stems from the spin-momentum locking of the topological surface states or rather from spin-Hall physics of the topological-insulator bulk, remains unclear. Here, we explore a mechanism of spin-torque generation purely based on the topological surface states. We consider topological-insulator-based bilayers involving ferromagnetic metal (TI/FM) and magnetically doped topological insulators (TI/mdTI), respectively. By ascribing the key theoretical differences between the two setups to location and number of active surface states, we describe both setups within the same framework of spin diffusion of the nonequilibrium spin density of the topological surface states. For the TI/FM bilayer, we find large spin-torque efficiencies of roughly equal magnitude for both in-plane and out-of-plane spin torques. For the TI/mdTI bilayer, we elucidate the dominance of the spin-transfer-like torque. However, we cannot explain the orders of magnitude enhancement reported. Nevertheless, our model gives an intuitive picture of spin-torque generation in topological-insulator-based bilayers and provides theoretical constraints on spin-torque generation due to topological surface states.en
dc.description.sponsorshipThe authors are grateful to A. Mellnik and D. Ralph for helpful discussions.M.H.F. and E.-A.K. acknowledge support from NSF Grant No. DMR-0955822 and from NSF Grant No. DMR-1120296 to the Cornell Center for Materials Research. M.H.F. further acknowledges the Swiss Society of Friends of the Weizmann Institute of Science. A.M. was supported by the King Abdullah University of Science and Technology (KAUST).en
dc.language.isoenen
dc.publisherAmerican Physical Society (APS)en
dc.relation.urlhttp://link.aps.org/doi/10.1103/PhysRevB.93.125303en
dc.rightsArchived with thanks to Physical Review Ben
dc.titleSpin-torque generation in topological insulator based heterostructuresen
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalPhysical Review Ben
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionDepartment of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israelen
dc.contributor.institutionDepartment of Physics, Stanford University, Stanford, California 94305, USAen
dc.contributor.institutionDepartment of Physics, Cornell University, Ithaca, New York 14853, USAen
dc.contributor.affiliationKing Abdullah University of Science and Technology (KAUST)en
kaust.authorManchon, Aurelienen
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