Effect of Rashba interaction at normal metal/insulator interface on spin-orbit torque of ferromagnet/normal metal/insulator trilayers

Eun Sang Park, Byoung Chul Min, Hyun Cheol Koo, Kyoung Whan Kim, Kyung Jin Lee

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

Based on a spin drift-diffusion model, we theoretically investigate the spin-orbit torque in ferromagnet/normal metal/insulator trilayers with considering the Rashba interfacial spin-orbit coupling at the normal metal/insulator interface. We find that the spin-orbit torque shows the opposite normal-metal-thickness dependences for the bulk spin-orbit coupling effect in the normal metal layer and for the interfacial spin-orbit coupling effect at the normal metal/insulator interface, offering a way to disentangle these two spin-orbit coupling effects. Moreover, we show that the conventional interpretation based on the bulk spin-orbit coupling effect overestimates the spin Hall angle and underestimates the spin diffusion length of the normal metal layer, when the interfacial contribution is non-negligible. Our result, a concise analytic expression of the spin-orbit torque considering both bulk and interface spin-orbit coupling effects, will be useful to design and interpret experiments on spin-orbit torque experiments in ferromagnet/normal metal/insulator trilayers.

Original languageEnglish
Pages (from-to)1362-1366
Number of pages5
JournalCurrent Applied Physics
Volume19
Issue number12
DOIs
Publication statusPublished - 2019 Dec

Bibliographical note

Funding Information:
This work was supported by the KIST Institutional program (Project Nos. 2V05750 , 2E29410 ). B.-C.M. and K.-W.K. acknowledge support from the National Research Council of Science & Technology (NST) (Grant No. CAP-16-01-KIST ). K.-W.K. acknowledges the German Research Foundation (No. SI 1720/2-1 ).

Funding Information:
This work was supported by the KIST Institutional program (Project Nos. 2V05750, 2E29410). B.-C.M. and K.-W.K. acknowledge support from the National Research Council of Science & Technology (NST) (Grant No. CAP-16-01-KIST). K.-W.K. acknowledges the German Research Foundation (No. SI 1720/2-1).

Publisher Copyright:
© 2019 Korean Physical Society

Keywords

  • Spin-orbit torque

ASJC Scopus subject areas

  • General Materials Science
  • General Physics and Astronomy

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