Visualizing and Manipulating Bilayer Graphene Quantum Dot States

ORAL

Abstract

Quantum confinement enables the control of a material's electronic, spin, and optical properties. A common platform to realize quantum confinement is a quantum dot (QD), which can be achieved through various methods such as electrostatic, self-assembly, and etching. Electrostatically defined monolayer and bilayer graphene QDs are unique compared to lateral semiconductor QDs because the quasi particles in the former possess chirality. As a result, upon normal incidence on a potential barrier monolayer graphene (MLG) features a 100% transmission (Klein tunneling) and bilayer graphene (BLG) features a 100% reflection (anti-Klein tunneling). Recently, several scanning tunneling spectroscopy (STS) studies have been performed on exposed electrostatically defined MLG QDs and have revealed chiral bound states with a tunable Berry phase. However, to date, no STS studies have directly probed the quasi-bound states in BLG QDs. Here we present our latest experimental progress on directly probing and manipulating the quasi-bound states in exposed BLG QDs with a scanning tunneling microscope (STM).

*This research was funded by NSF CAREER award under award number DMR-1753367. We also acknowledge support from the Army Research Office under contract W911NF-17-1-0473.

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Presenters

  • Zhehao Ge

    • Department of Physics, University of California, Santa Cruz
    • Physics, University of California, Santa Cruz
    • Physics Dept., University of California: Santa Cruz

Authors

  • Zhehao Ge

    • Department of Physics, University of California, Santa Cruz
    • Physics, University of California, Santa Cruz
    • Physics Dept., University of California: Santa Cruz

  • Frederic Joucken

    • University of California, Santa Cruz
    • Department of Physics, University of California, Santa Cruz
    • Physics Dept., University of California: Santa Cruz

  • Eberth A Quezada

    • Department of Physics, University of California, Santa Cruz
    • Physics, University of California, Santa Cruz
    • Physics Dept., University of California: Santa Cruz

  • Diego Rabelo da Costa

    • Physics, Universidade Federal do Ceará
    • Department of Physics, Federal University of Ceará

  • John Davenport

    • Department of Physics, University of California, Santa Cruz
    • Physics Dept., University of California: Santa Cruz

  • Biran Giraldo

    • Department of Electrical and Computer Engineering, University of California, Santa Cruz

  • Nobuhiko Kobayashi

    • Department of Electrical and Computer Engineering, University of California, Santa Cruz

  • 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

  • Tony Low

    • University of Minnesota
    • Department of Electrical & Computer Engineering, University of Minnesota
    • Electrical & Computer Engineering, University of Minnesota

  • Jairo Velasco Jr.

    • University of California, Santa Cruz
    • Department of Physics, University of California, Santa Cruz
    • Physics, University of California, Santa Cruz
    • Physics Dept., University of California: Santa Cruz