Tunable van Hove Singularities and Correlated States in Twisted Monolayer-bilayer Graphene

Research output: Contribution to journalArticlepeer-review

  • External authors:
  • Mohammed M. Al Ezzi
  • Nilanthy Balakrishnan
  • Aitor Garcia-Ruiz
  • Na Xin
  • Benjamin A. Piot
  • Takashi Taniguchi
  • Kenji Katayama
  • Alexandra Carvalho
  • Andre Geim
  • Vladimir Fal'ko
  • Shaffique Adam
  • Antonio Helio Castro Neto
  • Konstantin Novoselov
  • Yanmeng Shi

Abstract

Understanding and tuning correlated states is of great interest and significance to modern condensed matter physics. The recent discovery of unconventional superconductivity and Mott-like insulating states in magic-angle twisted bilayer graphene presents a unique platform to study correlation phenomena, in which the Coulomb energy dominates over the quenched kinetic energy as a result of hybridized flat bands. Extending this approach to the case of twisted multilayer graphene would allow even higher control over the band structure because of the reduced symmetry of the system. Here, we study electronic transport properties in twisted monolayer-bilayer graphene (a bilayer on top of monolayer graphene heterostructure). We observed the formation of van Hove singularities which are highly tunable by changing either the twist angle or external electric field and can cause strong correlation effects under optimum conditions. We provide basic theoretical interpretations of the observed electronic structure.

Bibliographical metadata

Original languageEnglish
JournalNature Physics
Publication statusAccepted/In press - 8 Jan 2021