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Locally mapping the phase diagram of alternating twist multilayer graphene: an STM and non-contact AFM study, part1

ORAL

Abstract

Alternating twist multilayer graphene has shown robust superconductivity and correlated insulating phases at partial filling of the moire band. However, the mechanisms of superconductivity and various phases and their relations to angle disorder between the layers remain elusive. We report STM/AFM measurements in twisted multilayer graphene at 10 mK to unveil the angle disorder effect. The structure of the device incorporates multiple stacked graphene layers rotated with alternating angles. The chosen angles are in the range between magic angles for twisted tri-layer and quad-layer graphene stacks. Atomically resolved STM measurements carried out on the tri- and quad-layer regions reveal the electronic states at lattice sites of different symmetry as a function of energy and filling factor. In addition, non-contact AFM measurements allow the tuning of displacement field revealing the phase diagram across microscopic different regions.

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Presenters

  • En-Min Shih

    National Institute of Standards and Technology, National Institute of Standards and Tech

Authors

  • En-Min Shih

    National Institute of Standards and Technology, National Institute of Standards and Tech

  • Dilek Yildiz

    NIST / JQI - Physics department UMD, Harvard University

  • Marlou R Slot

    National Institute of Standards and Technology

  • Sungmin Kim

    National Institute of Standards and Technology

  • Daniel T Walkup

    National Institute of Standards and Technology

  • Yulia Maximenko

    National Institute of Standards and Technology, National Institute of Standards and Tech

  • Steven Blankenship

    National Institute of Standards and Technology

  • Kenji Watanabe

    National Institute for Materials Science, Research Center for Functional Materials, National Institute of Materials Science, Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-044, Japan, NIMS, Research Center for Functional Materials, National Institute for Materials Science, National Institute for Materials Science, Japan, Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan, NIMS Japan

  • Takashi Taniguchi

    National Institute for Materials Science, Kyoto Univ, International Center for Materials Nanoarchitectonics, National Institute of Materials Science, Kyoto University, International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-044, Japan, International Center for Materials Nanoarchitectonics, National Institute for Materials Science, National Institute for Materials Science, Japan, National Institute For Materials Science, NIMS, National Institute for Material Science, International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan, NIMS Japan

  • Nikolai Zhitenev

    National Institute of Standards and Technology

  • Joseph A Stroscio

    National Institute of Standards and Technology, National Institute of Standards and Tech