Imaging Magic-Angle Twisted Bilayer Graphene: Part II

ORAL

Abstract

The flat bands in magic-angle twisted bilayer graphene (MATBG) host exotic quantum phases, including correlated insulating states, topologically non-trivial phases, and unconventional superconductors [1,2]. Strong interactions between electrons modulate the ground state from which such correlated phases emerge, and reconstruct the local electronic structure along with spatial symmetry breaking [3,4]. The ability to measure the local electronic excitation spectrum allows scanning tunneling microscopy (STM) to investigate the spatial dependence of the local electronic density of states (LDOS) and visualize the spatial characteristics of correlated phases using a variety of imaging techniques.

In this second talk in a series of three presentations, I will present how we use STM imaging and tunneling spectroscopy measurements to uncover distinctive real-space features of correlated quantum phases that result from strong electron interactions. I will discuss how these real-space features vary on several length scales and will discuss how they change as a function of carrier density, twist angle, and strain.

*This work was primarily supported by the Gordon and Betty Moore Foundation's EPiQS initiative grants GBMF9469 and DOE-BES grant DE-FG02-07ER4641.

Publication: [1] Y. Cao et al. Nature 556, 43-50, 80-84 (2018)
[2] K. Nuckolls et al. Nature 588, 610-615 (2020)
[3] D. Calugaru et al. Phys. Rev. Lett. 129, 117602 (2022)
[4] J. P. Hong et al. Phys. Rev. Lett. 129, 147001 (2022)

Presenters

  • Myungchul Oh

    • Princeton University

Authors

  • Myungchul Oh

    • Princeton University
  • Ryan L Lee

    • Princeton University
  • Kevin P Nuckolls

    • Princeton University
  • Dillon Wong

    • Princeton University
  • Tomohiro Soejima

    • University of California, Berkeley
  • Jung Pyo Hong

    • Princeton University
  • Jonah Herzog-Arbeitman

    • Princeton University
  • Dumitru Calugaru

    • Princeton University
  • 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
  • Nicolas Regnault

    • Princeton University
  • Andrei B Bernevig

    • Princeton University
  • Michael P Zaletel

    • University of California, Berkeley
    • UC Berkeley
  • Ali Yazdani

    • Princeton University