Dirac-Surface-State Modulated Spin Dynamics in a Ferrimagnetic Insulator at Room Temperature

ORAL

Abstract

The unique spin-momentum locking of the surface Dirac electrons in TI has been shown to be responsible for highly efficient spin-charge-conversion in ferromagnet (FM)/TI heterostructures. Here, we report the strongly modulated spin dynamics in yttrium iron garnet (YIG) due to the spin-momentum locked Dirac surface states in TI via ferromagnetic resonance. When the Bi-concentration x is systematically tuned in the 5 nm thick (BixSb1-x)2Te3 TI layer, the relative weight of the Dirac surface states varies. The Gilbert damping constant of the processing magnetization in YIG increases by one order of magnitude when the chemical potential of TI is close to the Dirac point. Remarkably, the magnetic anisotropy of YIG is also dramatically altered to favor in-plane orientation. The modification of the spin dynamics in YIG by the Dirac surface states at room temperature is much stronger than that in YIG-heavy metal heterostructures, which provides a superb knob for controlling ultrafast magnetization responses in potential nanoscale spintronic devices.

–

Presenters

  • Chi Tang

    University of California, Riverside, Univ of California - Riverside

Authors

  • Chi Tang

    University of California, Riverside, Univ of California - Riverside

  • Qi Song

    Physics, Peking University

  • Cui-Zu Chang

    Department of Physics, Pennsylvania State University, Pennsylvania State University, Department of Physics, The Pennsylvania State University, Physics, Pennsylvania State University

  • Yuichi Ohnuma

    Advanced Science Research Center Japan Atomic Energy Agency

  • Mamoru Matsuo

    Advanced Science Research Center Japan Atomic Energy Agency

  • Yawen Liu

    University of California, Riverside, Physics and Astronomy, University of Calirfornia, Riverside, Department of Physics and Astronomy, Univ. of California Riverside, Univ of California - Riverside

  • Wei Yuan

    Peking University, Physics, Peking University

  • Yunyan Yao

    Peking University, Physics, Peking University

  • Jagadeesh Moodera

    Physics, MIT, Physics, Massachusetts Institute of Technology, Department of Physics and Francis Bitter Magnet Lab, Massachusetts Institute of Technology, Department of Physics and Francis Bitter Magnet Lab, Massachusetts Institute of Technology,, Department of Physics, Massachusetts Institute of Technology, MIT, Department of Physics, Massachussetts Institute of Technology

  • Sadamichi Maekawa

    JAEA, Tohoku Univ, Advanced Science Research Center Japan Atomic Energy Agency

  • Wei Han

    Peking Univ, Peking University, Physics, Peking University

  • Jing Shi

    Univ of California - Riverside, Physics and Astronomy, University of Calirfornia, Riverside, University of California, Riverside, Physics, Univ of California - Riverside, Physics and Astronomy Department, University of California Riverside