Raman spectroscopy studies of spin waves in two-dimensional CrI<sub>3</sub>

ORAL

Abstract

The long-range magnetic order in the two-dimensional (2D) limit at finite temperatures has recently been demonstrated in a honeycomb Ising ferromagnet CrI3. It has triggered tremendous interest in 2D magnet-based applications. To achieve a complete understanding of the 2D magnetic phase, a direct measurement of the magnetic excitations, i.e., spin waves, or magnons, is pressingly in need. In this talk, we will present the experimental evidence of spin waves in the 2D honeycomb ferromagnet, CrI3. Using polarized micro-Raman spectroscopy, we have identified two branches of zero-momentum spin waves in 2D CrI3 with exceptionally high frequencies in the THz range, as compared to those of the conventional ferromagnets. By tracking the layer thickness dependence of both spin waves, we further show that both are surface magnons, and their lifetimes remain an order of magnitude longer than their temporal period down to the monolayer limit.

*L. Z acknowledges support by NSF CAREER Grant No. DMR-1749774. R. H. acknowledges support by NSF CAREER Grant No. DMR-1760668.

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Presenters

  • Wencan Jin

    • Department of Physics, University of Michigan
    • University of Michigan

Authors

  • Wencan Jin

    • Department of Physics, University of Michigan
    • University of Michigan

  • Hyun Ho Kim

    • University of Waterloo, Canada
    • University of Waterloo

  • Zhipeng Ye

    • Texas Tech University
    • Department of Electrical and Computer Engineering, Texas Tech University

  • Siwen Li

    • University of Michigan

  • Pouyan Rezaie

    • Department of Electrical and Computer Engineering, Texas Tech University
    • Texas Tech University

  • Fabian S Diaz

    • Texas Tech University

  • Saad Siddiq

    • Texas Tech University

  • Eric S Wauer

    • Texas Tech University

  • Bowen Yang

    • University of Waterloo

  • Chenghe Li

    • Renmin University of China

  • Shangjie Tian

    • Renmin University of China

  • Kai Sun

    • Physics, University of Michigan
    • Department of Physics, University of Michigan
    • Univ of Michigan - Ann Arbor
    • Physics Department, University of Michigan
    • University of Michigan

  • Hechang Lei

    • Physics Department, Renmin University of China
    • Brookhaven National Laboratory
    • Renmin University of China
    • Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory

  • Adam W Tsen

    • University of Waterloo

  • Rui He

    • Texas Tech University
    • Department of Electrical and Computer Engineering, Texas Tech University

  • Liuyan Zhao

    • Department of Physics, University of Michigan
    • University of Michigan
    • University of Michigan, Ann Arbor