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Atomic-scale structure and electronic properties of twisted double bilayer graphene: topological edge states and broken symmetries

ORAL

Abstract

Van der Waals materials stacked with an interlayer twist are an excellent platform towards achieving gate-tunable correlated phenomena linked to the formation of flat bands. We demonstrate the formation of correlated phases in twisted double bilayer graphene (tDBG) in two regimes of twist angle: minimally twisted (<0.1°) and 1.1°. Tiny-angle tDBG host large regions of uniform rhombohedral graphene where scanning tunneling spectroscopy reveals a sharp flat band of 3-5 meV half-width. We demonstrate that, when this flat band straddles the Fermi level, a correlated many-body gap emerges. Moreover, we show that ABCA graphene hosts surface topological edge states at natural interfaces with ABAB graphene. Scanning tunneling microscopy on tDBG at higher twist (~1.1°) reveals the presence of van Hove singularities on all inequivalent moiré sites. Tuning carrier density and displacement field reveals long-range broken C3 symmetry that emerge when the Fermi level is at the electronic flat bands. We demonstrate that the C3 symmetry breaking is a manifestation of an interaction-driven electronic nematic phase, which emerges even away from integer fillings. The nematic instability is an emergent phenomenon at the scale of the moiré lattice, pointing to its universal character.

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Presenters

  • Carmen Rubio Verdú

    Department of Physics, Columbia University, New York, New York 10027, USA, Columbia University, Physics, Columbia University

Authors

  • Carmen Rubio Verdú

    Department of Physics, Columbia University, New York, New York 10027, USA, Columbia University, Physics, Columbia University

  • Alexander Kerelsky

    Columbia University

  • Simon Turkel

    Department of Physics, Columbia University, New York, New York 10027, USA, Columbia University

  • Larry Song

    Department of Physics, Columbia University, New York, New York 10027, USA, Columbia University

  • Lennart Klebl

    RWTH Aachen University, Institute for Theory of Statistical Physics, RWTH Aachen University, and JARA Fundamentals of Future Information Technology, 52062 Aachen, Germany, Institute for Theory of Statistical Physics, Aachen University, RWTH Aachen, Institute for Theory of Statistical Physics, RWTH Aachen University

  • Rhine Samajdar

    Harvard University, Department of Physics, Harvard University, Cambridge, MA 02138, USA

  • Mathias Scheurer

    Universitat Innsbruck, Harvard University, University of Innsbruck, Department of Physics, Harvard University, Cambridge, MA 02138, USA

  • Jorn W. F. Venderbos

    Department of Physics, Drexel University, Philadelphia, PA 19104, USA, Drexel University, Department of Physics, Department of Materials Science and Engineering, Drexel University

  • Lei Wang

    Physics, Nanjing University, Columbia University, Physics, Columbia University, Cornell University

  • Dorri Halbertal

    Columbia University, Columbia Univ, Physics, Columbia University

  • Nathan R Finney

    Columbia University

  • Kenji Watanabe

    National Institute for Materials Science, National Institute for Materials Science, Japan, National Institure for Materials Science, Advanced Materials Laboratory, National Institute for Materials Science, NIMS, National Institute of Materials Science, National Institute for Materials Science (NIMS), Research Center for Functional Materials, National Institute for Materials Science, National Institute for Materials Science,1-1 Namiki, National Institute of Material Science, National Institute for Materials Science, Tsukuba, Japan, Research Center for Functional Materials, NIMS, National Institute of Materials Science, Tsukuba, Japan, National Institude for Materials Science, National Institute for Materials Science, Tsukuba, Ibaraki, Japan, Research Center for Functional Materials, National Institute for Materials Science, Tsukuba 305-0044, Japan, International Center for Materials Nanoarchitectonics, National Institute for Materials, NIMS - Japan, National Institute for Materials Science ,Japan, National Institute for Materials Science, Tsukuba, 305-0044, Ibaraki, Japan, National Institute for Material Science, National Institute for Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan, National Institute for Material Science Japan, NIMS Tsukuba, National Institute for Materials Science, Research Center for Functional Materials, Japan, Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan, National Institute for Materials Science: Namiki, Tsukuba, Ibaraki, JP, National Institue for Material Science, National Institute for Materials Science,1-1 Namiki, Tsukuba, 305-0044, Japan, Materials, NIMS, Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan, Research Center for Functional Materials, National In, Research Center for Functional Materials, Japan, International Center for Materials Nanoarchitectonics, National Institute for Materials Science, International Center for Materials nanoarchtectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan, NIMS Suguba, NIMS, Tsukuba, Japan, National Institute for Materials Science, Namiki 1-1, Tsukuba, 305-0044, Ibaraki, Japan, National institute of material science, Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan, Advanced Materials Laboratory, NIMS, Research Center for Functional Materials, National Institute for Materials Science, Ibaraki, Japan, National Institute for Materials Science, Research Center for Functional Materials, National Institute of Material Science, Japan, Tsukuba, National Institute for Materials Science

  • Takashi Taniguchi

    National Institute for Materials Science, National Institute for Materials Science, Japan, National Institure for Materials Science, Advanced Materials Laboratory, National Institute for Materials Science, NIMS, National Institute of Materials Science, National Institute for Materials Science (NIMS), International Center for Materials Nanoarchitectonics, National Institute for Materials Science, National Institute for Materials Science,1-1 Namiki, National Institute of Material Science, National Institute for Materials Science, Tsukuba, Japan, International Center for Materials Nanoarchitectonics, NIMS, Research Center for Functional Materials, National Institute for Materials Science, National Institute of Materials Science, Tsukuba, Japan, National Institude for Materials Science, International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba 305-0044, Japan, International Center for Materials Nanoarchitectonics, National Institute for Materials, NIMS - Japan, National Institute for Materials Science ,Japan, National Institute for Materials Science, Tsukuba, 305-0044, Ibaraki, Japan, National Institute for Material Science, National Institute for Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan, National Institute for Material Science Japan, 8International Center for Materials Nanoarchitectonics, NIMS Tsukuba, National Institute for Materials Science: Namiki, Tsukuba, Ibaraki, JP, National Institue for Material Science, National Institute for Materials Science,1-1 Namiki, Tsukuba, 305-0044, Japan, Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan, Research Center for Functional Materials, National In, Research Center for Functional Materials, Japan, Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan, International Center for Material Nanoarchitectonics, National Institute for Materials Science, International Center for Materials Nanoarchitectonics, NIMS Suguba, NIMS, Tsukuba, Japan, National Cheng Kung University, National Institute for Materials Science, Namiki 1-1, Tsukuba, 305-0044, Ibaraki, Japan, National institute of material science, Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan, Advanced Materials Laboratory, NIMS, National Institute for Materials Science, International Center for Materials Nanoarchitectonics, National Institute of Material Science, Japan, Tsukuba, National Institute for Materials Science

  • Hector Ochoa

    Columbia University, Department of Physics, Columbia University, New York, New York 10027, USA

  • Lede Xian

    Max Planck Institute for the Structure and Dynamics of Matter, Theory, Max Planck Institute for the Structure and Dynamics of Matter, Physics, Max Planck Institute, Max Planck Institute for Structure and Dynamics of Matter and Center for Free-Electron Laser Science, Max Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, 22761 Hamburg, Germany, Songshan Lake Materials Laboratory, Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany

  • Dante Kennes

    Institut fur Theorie der Statistischen Physik, RWTH Aachen, RWTH Aachen University, Institut für Theorie der Statistischen Physik, RWTH Aachen University, Institute for Theory of Statistical Physics, Aachen University, RWTH Aachen, Aachen, Institute for Theory of Statistical Physics, RWTH Aachen University

  • James Hone

    Columbia Univ, Columbia University, Department of Mechanical Engineering, Columbia University, Mechanical Engineering, Columbia University

  • Cory Dean

    Columbia University, Department of Physics, Columbia University, Physics, Columbia University, Columbia Univ

  • Dmitri Basov

    Columbia University, Department of Physics, Columbia University, Physics, Columbia University, Columbia Univ

  • Rafael Fernandes

    University of Minnesota, School of Physics and Astronomy, University of Minnesota, Physics, University of Minnesota, School of Physics and Astronomy, University of Minnesota, Minneapolis, 55455 MN, School of Physics and Astronomy, University of Minnesota, Minneapolis

  • Angel Rubio

    Max Plank Institute for the Structure and Dynamics of Matter; Center for Computational Quantum Physics Flatiron Institute, Max Planck Institute for the Structure and Dynamics of Matter, Theory, Max Planck Institute for the Structure and Dynamics of Matter, Max Planck Inst Structure & Dynamics of Matter, Physics, Max Planck Institute, Max Planck Institute for Structure and Dynamics of Matter and Center for Free-Electron Laser Science, Max Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, 22761 Hamburg, Germany, Max Planck Institute for the Structure and Dynamics of Matter and Center Free-Electron Laser Science, Hamburg, Germany, Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany, MPSD Hamburg, Max Planck Institute, Max Planck Inst Structure & Dynamics of Matter; Center for Computational Quantum Physics Flatiron Institute, Simons Foundation NY, USA, Theory, Max Planck Inst Structure & Dynamics of Matter

  • Abhay Narayan

    Department of Physics, Columbia University, Physics, Columbia University, Columbia Univ, Department of Physics, Columbia University, New York, New York 10027, USA, Columbia University