Ballistic transverse magnetic focusing in monolayer graphene on WSe<sub>2</sub>

ORAL

Abstract

It has been found that a large spin-orbit coupling (SOC) is induced in monolayer graphene by proximity with transition metal dichalcogenides (TMDC), as compared to the very weak one in pristine graphene. Theoretical calculation showed that the SOC splits the monolayer band and there exist two types: the valley-Zeeman term which couples the out-of-plane spin and valley degrees of freedom, and the Rashba term which couples the in-plane spin and sublattice degrees of freedom. Here we employ the transverse magnetic focusing technique to probe the effects of the SOC on the Fermi surface profile and electron dynamics in monolayer graphene-TMDC heterostructure. We clearly observed the spin-split band in graphene on WSe2, and quantitively estimated the sizes of both SOC terms by analyzing the TMF peaks. Interestingly, the second TMF peak didn’t show the splitting and theoretical analysis further shows that this is closely related to the effect of scattering at the sample edges and the spin conservation.

*The work is supported by Areas of Excellence Scheme (AoE/P-701/20), Early Career Scheme (27300819), and General Research Fund (1730020, 17300521, 17309722) from the Research Grant Council of Hong Kong SAR.

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Presenters

  • Qing Rao

    • The University of Hong Kong

Authors

  • Qing Rao

    • The University of Hong Kong

  • Wun-Hao Kang

    • National Cheng Kung University

  • Hongxia Xue

    • The University of Hong Kong

  • Kenji Watanabe

    • National Institute for Materials Science
    • Research Center for Functional Materials, National Institute of Materials Science
    • Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-044, Japan
    • NIMS
    • Research Center for Functional Materials, National Institute for Materials Science
    • National Institute for Materials Science, Japan
    • Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
    • NIMS Japan

  • Takashi Taniguchi

    • National Institute for Materials Science
    • Kyoto Univ
    • International Center for Materials Nanoarchitectonics, National Institute of Materials Science
    • Kyoto University
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-044, Japan
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science
    • National Institute for Materials Science, Japan
    • National Institute For Materials Science
    • NIMS
    • National Institute for Material Science
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
    • NIMS Japan

  • Ming-Hao Liu

    • National Cheng Kung University

  • Dong-Keun Ki

    • The University of Hong Kong