Visualizing unexpected magnetic field-tuned electron flow through ballistic channels

ORAL

Abstract

The advent of ultra-clean materials has enabled the exploration of ballistic flow, where electrons traverse a sample unperturbed before colliding with the walls. We have developed a nanoscale probe based on a scanning nanotube single electron transitor that is sufficiently sensitive to image the electrostatic potential of ballistic electrons in such materials for the first time. We apply this probe to high-mobility graphene channel devices, and image how the potential of the flowing electrons drops sharply at the contacts while remaining constant along the bulk, which is the textbook picture of ballistic electron flow. We then image how the Hall voltage profiles of the flowing electrons develop a rich set of patterns as the cyclotron radius is tuned by varying the perpendicular magnetic field. Contrary to the expectation that the electron current primarily flows along the edges in magnetic field, our results reveal that the current varies considerably across the bulk of the channel, and can even concentrate near the center. These results open the path for visualizing other ballistic electron flow phenomena that previously could only be studied via transport, including electron optics.

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Presenters

  • Joseph Sulpizio

    • Weizmann Institute of Science
    • Department of Condensed matter Physics, Weizmann Institute of Science, Rehovot 76100, Israel

Authors

  • Joseph Sulpizio

    • Weizmann Institute of Science
    • Department of Condensed matter Physics, Weizmann Institute of Science, Rehovot 76100, Israel

  • Lior Ella

    • Weizmann Institute of Science
    • Quantum Machines

  • Asaf Rozen

    • Weizmann Institute of Science

  • John Birkbeck

    • School of Physics and Astronomy, University of Manchester
    • University of Manchester
    • School of Physics & Astronomy, University of Manchester, Manchester M139PL, United Kingdom
    • Univ of Manchester

  • David Perello

    • School of Physics and Astronomy, University of Manchester
    • University of Manchester
    • School of Physics & Astronomy, University of Manchester, Manchester M139PL, United Kingdom

  • Debarghya Dutta

    • Weizmann Institute of Science

  • Moshe Ben-Shalom

    • Tel Aviv University

  • Takashi Taniguchi

    • National Institute for Materials Science, Japan
    • National Institute for Material Science
    • National Institute for Materials Science
    • National Institute for Materials Science, Tsukuba
    • Research Center for Functional Materials, NIMS
    • nims
    • Advanced Materials Laboratory, National Institute for Materials Science
    • National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • NIMS
    • National Institute for Material Science - Japan
    • NIMS Tsukuba
    • National Institute for Materials Science, Namiki 1-1, Ibaraki 305-0044, Japan.
    • National Institute for Materials Science (NIMS)
    • National Institute for Materials Science,Tsukuba, Ibaraki 305-0047, Japan
    • Advanced Materials Laboratory, NIMS, Japan
    • National Institute for Materials Science,1-1 Namiki, Tsukuba, 305-0044, Japan
    • National Institute of Materials Science
    • National Institute for Materials Science, University of Tsukuba
    • National Institute for Materials Science, Tsukuba, Japan
    • National Institue for Material Science, Tsukuba
    • Advanced Materials Laboratory, NIMS
    • Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba 305-0044, Japan
    • Advanced Matrials Lab, NIMS
    • National Institute for Material Science, Tsukuba, Japan
    • National institute for materials science
    • NIMS-Tsukuba
    • NIMS, Japan
    • National Institute for Materials Science, Namiki Tsukuba Ibaraki, Japan
    • Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Japan
    • NIMS Japan
    • National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan
    • Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Ibaraki, Japan
    • Advanced Materials Laboratory, National Institute of Materials Science
    • Advanced Materials Laboratory, National Institute for Materials Science 1-1 Namiki, Tsukuba, 305-0044, Japan
    • National Institute of Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • National Institute for Material Science (Japan)
    • Physics, NIMS
    • National Institute of Materials Science, Japan
    • National Institute of Materials Science, Tsukuba, Ibaraki 305-0044, Japan
    • NIMS - Tsukuba

  • Kenji Watanabe

    • National Institute for Materials Science, Japan
    • National Institute for Material Science
    • National Institute for Materials Science
    • National Institute for Materials Science, Tsukuba
    • Research Center for Functional Materials, NIMS
    • nims
    • Advanced Materials Laboratory, National Institute for Materials Science
    • National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • NIMS
    • National Institute for Material Science - Japan
    • NIMS Tsukuba
    • National Institute for Materials Science, Namiki 1-1, Ibaraki 305-0044, Japan.
    • National Institute for Materials Science (NIMS)
    • National Institute for Materials Science,Tsukuba, Ibaraki 305-0047, Japan
    • Advanced Materials Laboratory, NIMS, Japan
    • National Institute for Materials Science,1-1 Namiki, Tsukuba, 305-0044, Japan
    • National Institute of Materials Science
    • National Institute for Materials Science, University of Tsukuba
    • National Institute for Materials Science, Tsukuba, Japan
    • National Institute for Material Science, Japan
    • National Institue for Material Science, Tsukuba
    • Advanced Materials Laboratory, NIMS
    • Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba 305-0044, Japan
    • Advanced Matrials Lab, NIMS
    • National Institute for Material Science, Tsukuba, Japan
    • National institute for materials science
    • NIMS-Tsukuba
    • NIMS, Japan
    • National Institute for Materials Science, Namiki Tsukuba Ibaraki, Japan
    • NIRM
    • Advanced Materials Laboratory, National Institute for Materials Science, Tsukuba, Japan
    • NIMS Japan
    • National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan
    • Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Ibaraki, Japan
    • Advanced Materials Laboratory, National Institute of Materials Science
    • Advanced Materials Laboratory, National Institute for Materials Science 1-1 Namiki, Tsukuba, 305-0044, Japan
    • National Institute of Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan
    • National Institute for Material Science (Japan)
    • Physics, NIMS
    • National Institute of Materials Science, Japan
    • National Institute of Materials Science (NIMS)
    • National Institute of Materials Science, Tsukuba, Ibaraki 305-0044, Japan
    • NIMS - Tsukuba

  • Andre Geim

    • School of Physics and Astronomy, University of Manchester
    • University of Manchester
    • School of Physics & Astronomy, University of Manchester, Manchester M139PL, United Kingdom
    • Univ of Manchester

  • Shahal Ilani

    • Weizmann Institute of Science
    • Department of Condensed matter Physics, Weizmann Institute of Science, Rehovot 76100, Israel