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Pressure-enhanced fractional Chern insulators along a magic line in moiré transition metal dichalcogenides

Nicolás Morales-Durán1,2,*, Jie Wang3,4, Gabriel R. Schleder5,6, Mattia Angeli5, Ziyan Zhu7, Efthimios Kaxiras4,5, Cécile Repellin8, and Jennifer Cano9,2,†

  • 1Department of Physics, The University of Texas at Austin, Austin, Texas 78712, USA
  • 2Center for Computational Quantum Physics, Flatiron Institute, 162 5th Avenue, New York, New York 10010, USA
  • 3Center for Mathematical Sciences and Applications, Harvard University, Cambridge, Massachusetts 02138, USA
  • 4Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
  • 5John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
  • 6Brazilian Nanotechnology National Laboratory (LNNano), CNPEM, 13083-970 Campinas, São Paulo, Brazil
  • 7Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
  • 8Université Grenoble Alpes, CNRS, LPMMC, 38000 Grenoble, France
  • 9Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA

  • *na.morales92@utexas.edu
  • †jennifer.cano@stonybrook.edu
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Phys. Rev. Research 5, L032022 – Published 17 August, 2023

DOI: https://doi.org/10.1103/PhysRevResearch.5.L032022

Abstract

We show that pressure applied to twisted WSe2 can enhance the many-body gap and region of stability of a fractional Chern insulator at filling ν=1/3. Our results are based on exact diagonalization of a continuum model, whose pressure dependence is obtained through ab initio methods. We interpret our results in terms of a magic line in the pressure-vs-twist angle phase diagram: along the magic line, the bandwidth of the topmost moiré valence band is minimized while simultaneously its quantum geometry resembles that of an ideal Chern band. We expect our results to generalize to other twisted transition metal dichalcogenide homobilayers.

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Phys. Rev. Research 5, L032022– Published 17 August, 2023
  • Received 26 April 2023
  • Accepted 2 August 2023
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