Sublattice and Magnetic Field Resolved Scanning Tunneling Spectroscopy of ABA Trilayer Graphene Quantum Dots

ORAL

Abstract

Electrostatically defined graphene quantum dots (QDs) offer the opportunity to investigate unique quantum confinement phenomena due to the unique band structures hosted by graphene. For example, monolayer graphene (MLG) QDs can be used to investigate relativistic quantum phenomena, while Bernal stacked bilayer graphene (BLG) QDs allow investigation of the interplay between quantum confinement and non-trivial band geometry. Although MLG and BLG QDs have both been extensively studied previously, little experimental efforts have been made to investigate QDs that are based on graphene systems with more than two layers. In this talk, I will show our recent STM measurements on electrostatically defined Bernal stacked trilayer graphene (ABA TLG) QDs that are in-situ created by an STM tip bias pulsing technique. Our sublattice resolved scanning tunneling spectroscopy (STS) reveals the coexistence of MLG-like and BLG-like QD states with sublattice polarization in ABA TLG QDs. By performing magnetic field resolved constant bias dI/dV mapping, we demonstrate the dominance of MLG-like and BLG-like QD states can be switched in a magnetic field for ABA TLG QDs. Our results indicate ABA TLG QDs are a unique platform that can realize both MLG QD and BLG QD properties.

* We acknowledge support from the NSF CAREER award under award number DMR-1753367, the Army Research Office under contract W911NF-17-1-0473, Gordon and Betty Moore Foundation under grant ID GBMF11569.

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Presenters

  • Zhehao Ge

    University of California, Berkeley

Authors

  • Zhehao Ge

    University of California, Berkeley

  • Peter Polizogopoulos

    University of California, Santa Cruz

  • Koichi Tanaka

    University of Chicago

  • 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

  • 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

  • Aiming Yan

    University of California, Santa Cruz

  • Jairo Velasco Jr.

    University of California, Santa Cruz