Spin and valley-polarized multiple Fermi surfaces of α-RuCl<sub>3</sub>/bilayer graphene heterostructure

ORAL

Abstract

We report the transport properties of α-RuCl3/bilayer graphene heterostructures, where carrier doping is induced by a work function difference, resulting in distinct electron and hole populations in α-RuCl3 and bilayer graphene, respectively. Through a comprehensive analysis of multi-channel transport signatures, including Hall measurements and quantum oscillation, we unveil significant band modifications within the system. In particular, we observe the emergence of spin and valley-polarized multiple hole-type Fermi pockets, originating from the spin-selective band hybridization between α-RuCl3 and bilayer graphene, breaking the spin degree of freedom. Unlike the α-RuCl3/monolayer graphene system, the presence of different hybridization strengths between a-RuCl3 and the top and bottom graphene layers leads to an asymmetric behavior of the two layers, confirmed by effective mass experiments, resulting in the manifestation of valley-polarized Fermi pockets. These compelling findings establish α-RuCl3 proximitized to bilayer graphene as an outstanding platform for engineering its unique low-energy band structure.

*This work was supported by the Basic Science Research Program NRF-2020R1C1C1006914, the DGIST R&D Program (23-CoE-NT-01) of the Korean Ministry of Science and ICT, the DGIST-Caltech collaboration research program (23-KUJoint-01), and Samsung electronics. K.W. and T.T. acknowledge support from the JSPS KAKENHI (Grant Nos. 20H00354, 21H05233, and 23H02052) and World Premier International Research Center Initiative (WPI), MEXT, Japan. J.K. was supported by the National Research Foundation of Korea funded by the Korea government (MSIT) (No. NRF-2022R1F1A1059616).

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Presenters

  • Soyun Kim

    • Daegu Gyeongbuk Institute of Science and Technology

Authors

  • Soyun Kim

    • Daegu Gyeongbuk Institute of Science and Technology

  • Jeonghoon Hong

    • Indiana University Bloomington

  • Kenji Watanabe

    • National Institute for Materials Science
    • NIMS
    • Research Center for Functional Materials, National Institute for Materials Science
    • Research Center for Electronic and Optical Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • Research Center for Functional Materials, National Institute of Material Science, Tsukuba, Japan
    • National Institute of Materials Science
    • Advanced Materials Laboratory, National Institute for Materials Science

  • Takashi Taniguchi

    • National Institute for Materials Science
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science
    • Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • International Center for Materials Nanoarchitectonics, National Institute of Material Science, Tsukuba, Japan
    • Advanced Materials Laboratory, National Institute for Materials Science

  • Joseph L Falson

    • Caltech

  • Jeongwoo Kim

    • Incheon National University

  • Youngwook Kim

    • Daegu Gyeongbuk Institute of Science and Technology
    • Daegu Gyeongbuk Institute of Science and Technology (DGIST)