Topological Insulator/Magnetic Insulating Oxide: A Platform for Efficient Spin Current Transport

 · Invited

Abstract

Topological insulators (TIs) hold great promise for spintronic devices due to their large charge-to-spin conversion efficiency. It has been demonstrated that a TI can induce a spin-orbit torque to switch the magnetization of a magnetic metal. However, it is unclear if this is due to the topological surface state (TSS) because the electrons from the magnetic metal can suppress TSS. Here we discuss experiments that identified bona fide surface state-induced spin-orbit torques in topological insulator/magnetic oxide bilayers. In Bi2Se3/BaFe12O19, a large spin-orbit torque from Bi2Se3 switched the magnetization of BaFe12O19. When the magnetization was switched by a magnetic field, a current in Bi2Se3 can reduce the switching field by about 4000 Oe. The switching efficiency at 3 K is 300 times higher than at room temperature. When BaFe12O19 is replaced with Mg(Al,Fe)2O4, efficient spin pumping in the bulk-dominated regime was found at room temperature. These results highlight the promise of topological insulator/ferromagnetic insulating oxide bilayers as a platform for studying topological surface states in the context of spin-to-charge interconversion.

*Funding: The fabrication and characterization of the samples and the electrical measurements were supported mainly by the U.S. National Science Foundation under grant no. EFMA1641989. The data analyses were supported mainly by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under award DE-SC0018994. Work at PSU was supported by the Pennsylvania State Two-Dimensional Crystal Consortium-Materials Innovation Platform (2DCC-MIP) under the U.S. National Science Foundation grant no. DMR-1539916. Work at Argonne was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Science and Engineering Division. Work at UW was supported by the U.S. National Science Foundation under grant no. DMR-1710512. Work at Arizona was supported by the NSF under grant no. ECCS-1554011.

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Presenters

  • Peng Li

    • Auburn University
    • Electrical and Computer Engineering, Auburn University

Authors

  • Peng Li

    • Auburn University
    • Electrical and Computer Engineering, Auburn University

  • Steven S -L Zhang

    • case western reserve university
    • Department of Physics, Case Western University

  • Lauren Riddiford

    • Stanford University
    • Stanford Univ
    • Applied Physics, Stanford University

  • Timothy Pillsbury

    • Department of Physics, The Pennsylvania State University
    • Penn Sate University
    • Pennsylvania State University
    • Physics, Pennsylvania State University

  • Jinjun Ding

    • Colorado State University
    • Department of Physics, Colorado State University

  • James Kally

    • Penn Sate University

  • Alexander Grutter

    • National Institute of Standards and Technology
    • NIST Center for Neutron Research

  • Gaurab Rimal

    • Rutgers University, New Brunswick
    • Physics, Rutgers University
    • Department of Physics and Astronomy, Rutgers University
    • University of Wyoming
    • Department of Physics and Astronomy, Rutgers, The State University of New Jersey

  • Chong Bi

    • Stanford University

  • Gyorgy Csaba

    • Pazmany Peter Catholic University

  • J Samuel Jiang

    • Argonne National Laboratory
    • Materials Science Division, Argonne National Laboratory
    • Argonne Natl Lab

  • Junjia Ding

    • Argonne National Laboratory

  • Wei Zhang

    • Oakland University
    • Physics, Oakland University
    • Department of Physics, Oakland University
    • Electronic and Computer Engineering, Oakland University

  • Jinke Tang

    • University of Wyoming
    • Physics and Astronomy, University of Wyoming
    • Department of Physics and Astronomy, Univ of Wyoming
    • Uni of Wyoming

  • Weigang Wang

    • University of Arizona
    • Univ of Arizona

  • Olle Heinonen

    • Materials Science Division, Argonne National Lab
    • Argonne National Laboratory
    • Materials Science Division, Argonne National Laboratory
    • Argonne Natl Lab

  • Valentyn Novosad

    • Argonne National Laboratory
    • Materials Science Division, Argonne National Laboratory
    • Materials Science Division & Physics Division, Argonne Natl Lab

  • Axel Hoffmann

    • University of Illinois
    • Materials Science and Engineering, University of Illinois at Urbana Champaign
    • Argonne National Laboratory
    • University of Illinois Urbana-Champaign
    • University of Illinois at Urbana-Champaign
    • Materials Science and Engineering, University of Illinois at Urbana-Champaign
    • Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign
    • Materials Science Division, Argonne National Laboratory
    • Argonne Natl Lab

  • Nitin Samarth

    • Penn Sate University
    • Pennsylvania State University
    • Department of Physics, The Pennsylvania State University
    • Department of Physics, Pennsylvania State University

  • Yuri Suzuki

    • Stanford University
    • Stanford Univ
    • Dept. of Applied Physics, Stanford University
    • Geballe Laboratory for Advanced Materials, Stanford University
    • Applied Physics, Stanford University

  • Mingzhong Wu

    • Colorado State University
    • Department of Physics, Colorado State University
    • Physics Department, Colorado State University
    • Physics, Colorado State University