Multi-moiré torsional force microscopy as a tool to understand strain

Oral-In-person

Abstract

Over the past decade, electronic transport has revealed many novel correlated and topological states in moiré systems. These states can be strongly influenced by strain in the constituent layers [1].

Torsional force microscopy (TFM) is a non-destructive scanning probe technique that allows direct imaging of the moiré superlattice [2]. Using TFM, we image both graphene-graphene and graphene-BN moiré patterns over the same area. This allows spatially mapping strain and twist with few assumptions. The resulting maps inform the choice of locations for forming devices to study in cryogenic electronic transport measurements and allow correlating spatial structure with transport properties.

[1] Wang, X. et al. Unusual magnetotransport in twisted bilayer graphene from strain-induced open Fermi surfaces. Proceedings of the National Academy of Sciences 120, e2307151120 (2023).

[2] Pendharkar, M. et al. Torsional force microscopy of van der Waals moirés and atomic lattices. Proceedings of the National Academy of Sciences 121, e2314083121 (2024).

Presenters

  • Benjamin Alexander

    • Stanford University

Authors

  • Benjamin Alexander

    • Stanford University
  • Steven Tran

    • Stanford University
  • Rupini Kamat

    • Stanford University
  • Jan-Lucas Uslu

  • Chaitrali Duse

    • Stanford University
  • Mihir Pendharkar

    • Stanford University
  • Kenji Watanabe

    • National Institute for Materials Science
  • Takashi Taniguchi

    • National Institute for Materials Science
  • David Goldhaber-Gordon

    • Stanford University