Analytical description of ballistic spin currents and torques in magnetic tunnel junctions

Handle URI:
http://hdl.handle.net/10754/579490
Title:
Analytical description of ballistic spin currents and torques in magnetic tunnel junctions
Authors:
Chshiev, M.; Manchon, Aurelien ( 0000-0002-4768-293X ) ; Kalitsov, A.; Ryzhanova, N.; Vedyayev, A.; Strelkov, N.; Butler, W. H.; Dieny, B.
Abstract:
In this work we demonstrate explicit analytical expressions for both charge and spin currents which constitute the 2×2 spinor in magnetic tunnel junctions with noncollinear magnetizations under applied voltage. The calculations have been performed within the free electron model in the framework of the Keldysh formalism and WKB approximation. We demonstrate that spin/charge currents and spin transfer torques are all explicitly expressed through only three irreducible quantities, without further approximations. The conditions and mechanisms of deviation from the conventional sine angular dependence of both spin currents and torques are shown and discussed. It is shown in the thick barrier approximation that all tunneling transport quantities can be expressed in an extremely simplified form via Slonczewski spin polarizations and our effective spin averaged interfacial transmission probabilities and effective out-of-plane polarizations at both interfaces. It is proven that the latter plays a key role in the emergence of perpendicular spin torque as well as in the angular dependence character of all spin and charge transport considered. It is demonstrated directly also that for any applied voltage, the parallel component of spin current at the FM/I interface is expressed via collinear longitudinal spin current components. Finally, spin transfer torque behavior is analyzed in a view of transverse characteristic length scales for spin transport.
KAUST Department:
Physical Sciences and Engineering (PSE) Division
Citation:
Analytical description of ballistic spin currents and torques in magnetic tunnel junctions 2015, 92 (10) Physical Review B
Publisher:
American Physical Society (APS)
Journal:
Physical Review B
Issue Date:
21-Sep-2015
DOI:
10.1103/PhysRevB.92.104422
Type:
Article
ISSN:
1098-0121; 1550-235X
Additional Links:
http://link.aps.org/doi/10.1103/PhysRevB.92.104422
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorChshiev, M.en
dc.contributor.authorManchon, Aurelienen
dc.contributor.authorKalitsov, A.en
dc.contributor.authorRyzhanova, N.en
dc.contributor.authorVedyayev, A.en
dc.contributor.authorStrelkov, N.en
dc.contributor.authorButler, W. H.en
dc.contributor.authorDieny, B.en
dc.date.accessioned2015-10-08T07:41:48Zen
dc.date.available2015-10-08T07:41:48Zen
dc.date.issued2015-09-21en
dc.identifier.citationAnalytical description of ballistic spin currents and torques in magnetic tunnel junctions 2015, 92 (10) Physical Review Ben
dc.identifier.issn1098-0121en
dc.identifier.issn1550-235Xen
dc.identifier.doi10.1103/PhysRevB.92.104422en
dc.identifier.urihttp://hdl.handle.net/10754/579490en
dc.description.abstractIn this work we demonstrate explicit analytical expressions for both charge and spin currents which constitute the 2×2 spinor in magnetic tunnel junctions with noncollinear magnetizations under applied voltage. The calculations have been performed within the free electron model in the framework of the Keldysh formalism and WKB approximation. We demonstrate that spin/charge currents and spin transfer torques are all explicitly expressed through only three irreducible quantities, without further approximations. The conditions and mechanisms of deviation from the conventional sine angular dependence of both spin currents and torques are shown and discussed. It is shown in the thick barrier approximation that all tunneling transport quantities can be expressed in an extremely simplified form via Slonczewski spin polarizations and our effective spin averaged interfacial transmission probabilities and effective out-of-plane polarizations at both interfaces. It is proven that the latter plays a key role in the emergence of perpendicular spin torque as well as in the angular dependence character of all spin and charge transport considered. It is demonstrated directly also that for any applied voltage, the parallel component of spin current at the FM/I interface is expressed via collinear longitudinal spin current components. Finally, spin transfer torque behavior is analyzed in a view of transverse characteristic length scales for spin transport.en
dc.language.isoenen
dc.publisherAmerican Physical Society (APS)en
dc.relation.urlhttp://link.aps.org/doi/10.1103/PhysRevB.92.104422en
dc.rightsArchived with thanks to Physical Review Ben
dc.titleAnalytical description of ballistic spin currents and torques in magnetic tunnel junctionsen
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalPhysical Review Ben
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionUniv. Grenoble Alpes, INAC-SPINTEC, F-38000 Grenoble, Franceen
dc.contributor.institutionCNRS, SPINTEC, F-38000 Grenoble, Franceen
dc.contributor.institutionCEA, INAC-SPINTEC, F-38000 Grenoble, Franceen
dc.contributor.institutionMINT Center, University of Alabama, Tuscaloosa, Alabama 35487-0209, USAen
dc.contributor.institutionDepartment of Physics, Moscow Lomonosov State University, Moscow 119991, Russiaen
dc.contributor.affiliationKing Abdullah University of Science and Technology (KAUST)en
kaust.authorManchon, Aurelienen
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