Observation of charging peaks near the flat band in magic-angle twisted bilayer Graphene

ORAL

Abstract

Magic-angle twisted bilayer Graphene (MA-tBLG) has emerged as a highly tunable platform to study correlation physics. Numerous transport experiments have shown the existence of correlated insulating states, unconventional superconductivity and emergent ferromagnetism as the filling of the flat moire bands in MA-tBLG is tuned. More recently, several Scanning Tunneling Microscopy/Spectroscopy (STM/STS) experiments have also observed correlated-insulator like behavior, charge order and broken C3 symmetry in this system. Here, using Low temperature STM/STS measurements, we report the observation of sharp charging peaks which appear in the LDOS as the Fermi level is tuned close to the edges of the flat band. We perform a systematic study of these states to see their evolution in space using STS mapping. The observation of these states hints at the formation of local compressible regions surrounded by a gapped incompressible region because of tip induced band bending.

*Work supported by DOE-FG02-99ER45742, NSF DMR 1708158

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Presenters

  • Nikhil Tilak

    • Rutgers University, New Brunswick
    • Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08855 USA

Authors

  • Nikhil Tilak

    • Rutgers University, New Brunswick
    • Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08855 USA

  • Xinyuan Lai

    • Rutgers University, New Brunswick
    • Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08855 USA
    • Rutgers Univeristy

  • Yuhang Jiang

    • University of Chinese Academy of Sciences
    • Department of Physics and Astronomy, University of Chinese Academy of Sciences, CM5J+7X, Huaibeizhen, Huairou, Beijing, China

  • Jinhai Mao

    • University of Chinese Academy of Sciences
    • Department of Physics and Astronomy, University of Chinese Academy of Sciences, CM5J+7X, Huaibeizhen, Huairou, Beijing, China

  • Mingyu Xu

    • Iowa State University
    • Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
    • Ames Laboratory, Iowa State University, Dept. of Physics and Astronomy, Ames
    • Ames Laboratory, Iowa State University

  • Raquel de Almeida Ribeiro

    • Iowa State University
    • Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA

  • Paul C Canfield

    • Iowa State University
    • Ames Laboratory and Iowa State University
    • Ames Lab
    • Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
    • Ames laboratory, Ames, IA
    • Ames Laboratory, Iowa State University
    • Department of Physics & Astronomy, Iowa State University/Ames Laboratory
    • Department of Physics and Astronomy, Iowa State University/Ames Laboratory
    • Iowa State University and Ames Laboratory
    • Iowa State University, Ames Laboratory
    • Department of Physics and Astronomy, Iowa State University
    • Division of Materials Sciences & Engineering, Ames Lab and Iowa State University
    • Department of Physics and Astronomy, Ames Laboratory/Iowa State Univeristy
    • Iowa State University/Ames Laboratory

  • Eva Andrei

    • Rutgers University, New Brunswick
    • Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08855 USA
    • Rutgers Univeristy
    • Department of physics and Astronomy, Rutgers University