Coupling of Quantum Valley Hall Edge States between CVD Bilayer Graphene Layer Stacking Domain Walls

ORAL

Abstract

Quantum valley Hall (QVH) edge states are topologically protected in the absence of valley mixing. In addition to the long mean free path from the protection, their inter-wall coupling enables novel properties such as current partition and valley filtering, when arranged in specific configurations. Stacking order alternation across a boundary in Bernal stacking bilayer graphene creates a layer stacking wall (LSW) where QVH edge states are bound. However, the uncontrollable strain of LSWs upon their creation places a big challenge to study their inter-wall coupling. Here we use different strain mechanisms during chemical vapor deposition (CVD) and subsequent transfer processess to create well-separated LSWs and close packing LSW bundles, and report inter-wall coupling of QVH edge states in the latter case through electron transport measurements.

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Presenters

  • Qicheng Zhang

    • University of Pennsylvania
    • Physics, University of Pennsylvania

Authors

  • Qicheng Zhang

    • University of Pennsylvania
    • Physics, University of Pennsylvania

  • Sheng Wang

    • University of California at Berkeley
    • University of California, Berkeley
    • Department of Physics, University of California, Berkeley

  • Zhaoli Gao

    • University of Pennsylvania
    • Department of Physics and Astronomy, University of Pennsylvania

  • Sebastian Hurtado Parra

    • University of Pennsylvania

  • Paul Masih Das

    • University of Pennsylvania

  • Joel M Berry

    • University of Pennsylvania
    • Lawrence Livermore National Laboratory

  • Zachariah M Addison

    • University of Pennsylvania

  • William Parkin

    • University of Pennsylvania

  • Marija Drndic

    • University of Pennsylvania

  • James Makato Kikkawa

    • University of Pennsylvania

  • Eugene John Mele

    • University of Pennsylvania

  • Feng Wang

    • University of California at Berkeley
    • University of California, Berkeley
    • UC Berkeley
    • Physics, University of California, Berkeley
    • University of California, Berkeley and MSD, LBNL
    • Department of Physics, University of California, Berkeley

  • Zhengtang Luo

    • Hong Kong University of Science and Technology

  • Alan T Johnson

    • University of Pennsylvania
    • Department of Physics and Astronomy, University of Pennsylvania
    • Physics, University of Pennsylvania