Very high spin Hall conductivities and spin Hall ratios in epitaxial Iridium di-oxide films

ORAL

Abstract

New metallic materials with exceptionally high spin Hall conductivities and accompanying high spin Hall ratios are desirable both to produce more efficient systems for spin-orbit torque applications and to further test the fundamental understanding of intrinsic spin-orbit interactions. A particularly interesting candidate for such research is the metallic rutile oxide Iridium di-oxide which angle resolved photoemission spectroscopy studies have shown exhibits Dirac nodal lines in the band structure, a feature that could enable a very high . Here we report spin-torque ferromagnetic resonance studies of the damping-like and field-like torques exerted on an adjacent ferromagnetic layer as the result of current flowing in epitaxial (110) and (001) IrO2 films. The (110) films exhibit a damping-like torque efficiency ≈ 0.18 at 293 K, which sets a lower bound for the spin Hall conductivity . The higher resistivity (~ 300 µΩ-cm) (001) films exhibit even stronger spin-orbit torques, with ranging from ~0.45 at 293K to 0.8 at 30 K as decreases, behavior indicative of the dirty metal regime. The very high value for (001) IrO2, ≥ , is both a challenge for current theoretical understanding and an exciting prospect for more efficient SOT applications.

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Presenters

  • ARNAB BOSE

    • School of Applied and Engineering Physics, Cornell University
    • Cornell University

Authors

  • ARNAB BOSE

    • School of Applied and Engineering Physics, Cornell University
    • Cornell University

  • Jocienne Nelson

    • Department of Physics, Cornell University, Cornell University
    • Cornell University

  • Xiyue Zhang

    • School of Applied and Engineering Physics, Cornell University

  • Raksit Jain

    • School of Applied and Engineering Physics, Cornell University

  • Shengjie Shi

    • School of Applied and Engineering Physics, Cornell University
    • Cornell University

  • Darrell Schlom

    • Cornell University
    • Department of Materials Science and Engineering, Cornell University
    • Department of Materials Science and Engineering, Kavli Institute at Cornell for Nanoscale Science, Cornell University
    • Materials Science and Engineering, Cornell University
    • Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853, USA
    • Platform for the Accelerated Realization, Analysis, & Discovery of Interface Materials (PARADIM), Cornell University

  • Daniel C. Ralph

    • Department of Physics, Cornell University, Cornell University
    • Cornell University
    • Physics, Cornell

  • David Muller

    • Cornell University
    • School of Applied and Engineering Physics, Cornell University
    • Applied and Engineering Physics, Cornell University

  • Kyle M Shen

    • Cornell University
    • Department of Physics, Cornell University, Cornell University
    • Department of Physics, Laboratory of Atomic and Solid State Physics, Cornell University
    • Laboratory of Atomic and Solid State Physics, Department of Physics, Kavli Institute at Cornell for Nanoscale Science, Cornell University

  • Robert Buhrman

    • School of Applied and Engineering Physics, Cornell University
    • Cornell University
    • Physics, Cornell University