Origin of magneto-crystalline anisotropy underlying 2D ferromagnetism in CrI<sub>3</sub> single crystals from ferromagnetic resonance

ORAL

Abstract


We provide the detailed magnetic anisotropy structure of a CrI3 single crystal obtained through the measurement of the angle dependence of ferromagnetic resonance. We present a microscopic spin model describing the anisotropic interactions in a monolayer in terms of the experimentally measured Heisenberg, Kitaev, symmetric-anisotropic and quadrupole interactions that incorporate the material’s crystal symmetries. Comparison of Tc calculated using spin wave theory with the experimentally known values reveals that CrI3 is dominantly a Kitaev ferromagnet rather than Heisenberg. We also find that symmetric-anisotropic interaction stabilizes 2D ferromagnetic order by opening the magnon gap ~ 0.4 meV at the center of the Brillouin zone and we predict a Kitaev-interaction-induced ~ 5 meV magnon gap opening at the Dirac point. This work clarifies the complex anisotropic behaviour of spins in CrI3, opening a route to develop 2D ferromagnets with higher Tc and explore novel 2D spin orders arising from Kitaev physics in van der Waals materials.

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Presenters

  • Inhee Lee

    • Ohio State University
    • Department of Physics, The Ohio State University

Authors

  • Inhee Lee

    • Ohio State University
    • Department of Physics, The Ohio State University

  • Kyusung Hwang

    • Ohio State University
    • Department of Physics, The Ohio State University

  • Utermohlen G. Franz

    • Ohio State University

  • Daniel Weber

    • Ohio State University
    • Department of Chemistry and Biochemistry, The Ohio State University
    • Department of Chemistry, Ohio State University

  • Chi Zhang

    • Ohio State University
    • Department of Physics, The Ohio State University

  • Johan Van Tol

    • National High Magnetic Field Laboratory
    • National High Magnetic Field Laboratory, Florida State University
    • National High Magnetic Field Lab

  • Stephen Hill

    • National High Magnetic Field Laboratory
    • Florida State University

  • Joshua E. Goldberger

    • Ohio State University
    • Department of Chemistry and Biochemistry, The Ohio State University

  • Nandini Trivedi

    • Ohio State University
    • Department of Physics, The Ohio State University
    • Department of Physics, Ohio State University
    • The Ohio State University
    • Physics, Ohio State University

  • P Chris Hammel

    • Ohio State University
    • Department of Physics, The Ohio State University
    • Department of Physics, Ohio State University