Strongly coupled edge states and frequency doubling in a graphene quantum Hall interferometer

ORAL

Abstract

Electronic interferometers using chiral, one-dimensional (1D) edge channels of the quantum Hall effect (QHE) can demonstrate a wealth of fundamental phenomena including quasiparticle exchange statistics. When multiple edge channels are involved, FP interferometers in past works have also exhibited Aharonov-Bohm (AB) interference frequency doubling, suggesting pairing of elementary charges to form 2e quasiparticles. Here, following our recent report we discuss measurements in a highly tunable graphene-based QHE FP interferometer that elucidates the connection between interferometer phase jump and AB frequency doubling. By tuning the electron density from the QHE filling factors ν < 2 to ν > 7, we observe continuously modulating periodic interference phase jumps leading to apparent AB oscillation frequency doubling. These results reveal that repulsive Coulomb coupling between the spin-split, copropagating edge channels can explain aspects of this novel strongly coupled regime, where a perfect anti-correlation exists between the two channels. These results expand the understanding of edge state coupling in multichannel QHE interferometers and provide an informative framework for future multi-edge interference experiments.

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Presenters

  • Thomas Werkmeister

    • Harvard University

Authors

  • Thomas Werkmeister

    • Harvard University

  • James Ehrets

    • Harvard University

  • Yuval Ronen

    • Harvard University
    • Weizmann Institute of Science

  • Marie E Wesson

    • Harvard University

  • Kenji Watanabe

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

  • Takashi Taniguchi

    • Kyoto Univ
    • National Institute for Materials Science
    • Research Center for Materials Nanoarchitectonics
    • Research Center for Materials Nanoarchitectonics, National Institute for Materials Science
    • National Institute for Materials Sciences
    • NIMS
    • International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • National Institute for Material Science
    • International Center for Materials Nanoarchitectonics, NIMS, Japan
    • International Center for Materials Nanoarchitectonics, Tsukuba
    • National Institue for Materials Science
    • Kyoto University
    • National Institute of Materials Science
    • International Center for Materials Nanoarchitectonics and National Institute for Materials Science

  • D. E Feldman

    • Brown University

  • Bertrand I Halperin

    • Harvard University

  • Amir Yacoby

    • Harvard University

  • Philip Kim

    • Harvard University