Tuning a Circular p-n Junction in Graphene from Quantum Confinement to Optical Guiding

POSTER

Abstract

The photon-like propagation of the Dirac-electrons in graphene together with the record-high electronic mobility can lead to applications based on ultra-fast electronic response and low dissipation. But the chiral nature of the charge-carriers which is responsible for the high mobility also makes it difficult to control their motion and prevents electronic switching. Here we show how to manipulate the charge-carriers by using a circular p-n junction whose size can be continuously tuned from the nanometer to the micrometer scale. The junction size is controlled with a dual-gate device consisting of a planar back-gate and a point-like top-gate made by decorating an STM tip with an Au nanowire. The nanometer-scale junction is defined by a deep potential well created by the tip-induced charge. It traps the Dirac-electrons in quantum-confined states which are the graphene equivalent of the atomic collapse states predicted to occur at super-critically charged nuclei. As the junction size increases, the transition to the optical regime is signaled by the emergence of whispering-gallery modes1.

1Y. Jiang, et al, Nature Nanotechnology (2017) doi:10.1038/nnano.2017.181

*DOE-FG02-99ER45742, NSF-DMR 1708158, ESF-EUROCORES- EuroGRAPHENE, FWO-VI and Methusalem program of the Flemish government

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Presenters

  • Yuhang Jiang

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

Authors

  • Yuhang Jiang

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

  • Jinhao Mao

    • Department of Physics and Astronomy, Rutgers University

  • Dean Moldovan

    • Departement Fysica, Universiteit Antwerpen

  • Massoud Ramezani Masir

    • Department of Physics, University of Texas at Austin
    • Physics, University of Texas at Austin

  • Guohong Li

    • Department of Physics and Astronomy, Rutgers University
    • Physics and Astronomy, Rutgers Univ
    • Physics and Astronomy, Rutgers University

  • Kenji Watanabe

    • National Institute for Materials Science
    • NIMS
    • National Institute for Material Science
    • Advanced Materials Laboratory, National Institute for Materials Science
    • National Institute of Materials Science
    • Research Center for Functional Materials, National Institute for Materials Science
    • National Institute for Materials Science (NIMS
    • Advanced Materials Laboratory, NIMS
    • National Institute for Materials Science, Advanced Materials Laboratory
    • National Institue for Materials Science
    • National Institute of Material Science
    • National Institute for Matericals Science
    • Advanced Materials Laboratory
    • National Institute for Materials Science, 1-1 Namiki
    • Advanced materials laboratory, National institute for Materials Science
    • NIMS-Japan

  • Takashi Taniguchi

    • National Institute for Materials Science
    • NIMS
    • National Institute for Material Science
    • Advanced Materials Laboratory, National Institute for Materials Science
    • National Institute of Materials Science
    • Research Center for Functional Materials, National Institute for Materials Science
    • National Institute for Materials Science (NIMS
    • Advanced Materials Laboratory, NIMS
    • National Institute for Materials Science, Advanced Materials Laboratory
    • National Institue for Materials Science
    • National Institute of Material Science
    • National Institute for Matericals Science
    • Advanced Materials Laboratory
    • National Institute for Materials Science, 1-1 Namiki
    • NIMS-Japan

  • François Peeters

    • Departement Fysica, Universiteit Antwerpen
    • Department of Physics, University of Antwerp
    • University of Antwerp

  • Eva Andrei

    • Department of Physics and Astronomy, Rutgers University
    • Physics and Astronomy, Rutgers Univ
    • Physics and Astronomy, Rutgers University
    • Department of Physics and Astronomy, Rutgers the State Univ of NJ New Brunswick