Evidence for Interlayer Coupling and Moire Periodic Potentials in Twisted Bilayer Graphene

Abstract

We report a study of the valence band dispersion of twisted bilayer graphene using angle-resolved photoemission spectroscopy and ab initio calculations. We observe two noninteracting cones near the Dirac crossing energy and the emergence of van Hove singularities where the cones overlap for large twist angles (> 5 deg). Besides the expected interaction between the Dirac cones, minigaps appeared at the Brillouin zone boundaries of the moire superlattice formed by the misorientation of the two graphene layers. We attribute the emergence of these minigaps to a periodic potential induced by the moire. These anticrossing features point to coupling between the two graphene sheets, mediated by moire periodic potentials.

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Document Details

Document Type
Technical Report
Publication Date
Nov 02, 2012
Accession Number
ADA590798

Entities

People

  • Aaron Bostwick
  • Eli Rotenberg
  • Jeremy T. Robinson
  • Peter J. Feibelman
  • Taisuke Ohta
  • Thomas E. Beechem

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Advanced Electronics

DTIC Thesaurus Topics

  • Band Structures
  • Charge Carriers
  • Computational Chemistry Methods
  • Couplings
  • Density Functional Theory
  • Diffraction
  • Electron Energy
  • Electrons
  • Energy Bands
  • Graphene
  • Materials
  • Materials Science
  • Silicon Carbide
  • Solid State Physics
  • Spectra
  • Spectroscopy
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Quantum Dot Semiconductor Device Photonics and Graphene Optoelectronic Materials and THz Physics.
  • Quantum spin resonance or Electron Paramagnetic Resonance spectroscopy.

Technology Areas

  • Microelectronics
  • Microelectronics - Graphene