Anomalous spin-orbit torques in a ferromagnetic metal

 · Invited

Abstract

Current-induced spin-orbit torques have attracted a considerable amount of attention in recent years. The typical structure for studying the spin-orbit torque is a ferromagnetic metal/ nonmagnetic material bilayer. Most research has focused on the spin-orbit torque generated externally by the nonmagnetic material, overlooking the possibility that the ferromagnetic metal can generate spin-orbit torque on itself. We recently discovered that a ferromagnetic metal can in fact generate equal and opposite spin-orbit torques at its surfaces, which is termed as the anomalous spin-orbit torque, due to its analogy to the anomalous spin Hall effect. The strong anomalous spin-orbit torque may challenge our current understanding of spin-orbit torque in bilayer/multilayer systems. It also provides new opportunities that ferromagnet itself can be a source of spin-orbit torques.
[1] W. Wang, T. Wang, V.P. Amin, Y. Wang, A. Radhakrishnan, A. Davidson, S.R. Allen, T.J. Silva, H. Ohldag, D. Balzar, B.L. Zink, P.M. Haney, J.Q. Xiao, D.G. Cahill, V.O. Loren, X. Fan, “Anomalous spin-orbit torques in magnetic single-layer films”, Nature Nanotechnology 14, 819-824 (2019)

*The work carried out at the University of Denver is partially supported by the PROF and by the National Science Foundation under grant no. ECCS-1738679. W.W., D.G.C. and V.O.L. acknowledge support from the NSF-MRSEC under award no. DMR-1720633. T.W., Y.W. and J.Q.X. acknowledge support from the NSF under award no. DMR-1505192. V.P.A. acknowledges support under the Cooperative Research Agreement between the University of Maryland and the National Institute of Standards and Technology Center for Nanoscale Science and Technology, award 70NANB14H209, through the University of Maryland.

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Presenters

  • Xin Fan

    • Univ of Denver
    • Physics and Astronomy, Univ of Denver

Authors

  • Wenrui Wang

    • Physics, University of Illinois Urbana Champaign

  • Tao Wang

    • University of Delaware
    • Physics and Astronomy, University of Delaware

  • Vivek P Amin

    • Center for Nanoscale Science and Technology, National Institute of Standards and Technology

  • Yang Wang

    • University of Delaware
    • Physics and Astronomy, University of Delaware

  • Anil Radhakrishnan

    • Physics, University of Illinois Urbana Champaign

  • Angie Davidson

    • Physics and Astronomy, Univ of Denver

  • Shane R Allen

    • Physics and Astronomy, Univ of Denver

  • Thomas Silva

    • National Institute of Standards and Technology Boulder
    • Quantum Electromagnetics Division, National Institute of Standards and Technology

  • Hendrik Ohldag

    • Lawrence Berkeley National Laboratory

  • Davor Balzar

    • Physics and Astronomy, Univ of Denver

  • Barry L Zink

    • Physics and Astronomy, Univ of Denver
    • Univ of Denver

  • Paul Haney

    • Center for Nanoscale Science and Technology, National Institute of Standards and Technology
    • National Institute of Standards and Technology

  • John Q Xiao

    • University of Delaware
    • Physics and Astronomy, University of Delaware

  • David Cahill

    • Department of Materials Science and Engineering, University of Illinois Urbana Champaign
    • Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign
    • University of Illinois at Urbana-Champaign

  • Virginia O Lorenz

    • Physics, University of Illinois Urbana Champaign
    • University of Illinois at Urbana-Champaign

  • Xin Fan

    • Univ of Denver
    • Physics and Astronomy, Univ of Denver