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  • Letter
  • Open Access

Moiré flat Chern bands and correlated quantum anomalous Hall states generated by spin-orbit couplings in twisted homobilayer MoS2

Benjamin T. Zhou*, Shannon Egan, and Marcel Franz†

  • Department of Physics and Astronomy & Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver BC, Canada V6T 1Z4

  • *Corresponding author: benjamin.zhou@ubc.ca
  • †Corresponding author: franz@phas.ubc.ca
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Phys. Rev. Research 4, L012032 – Published 16 March, 2022

DOI: https://doi.org/10.1103/PhysRevResearch.4.L012032

Abstract

We predict that in a twisted homobilayer of transition-metal dichalcogenide MoS2, spin-orbit coupling in the conduction band states from ±K valleys, can give rise to moiré flat bands with nonzero Chern numbers in each valley. The nontrivial band topology originates from a unique combination of angular twist and local mirror symmetry breaking in each individual layer, which results in unusual skyrmionic spin textures in momentum space with skyrmion number S=±2. Our Hartree-Fock analysis further suggests that density-density interactions generically drive the system at 1/2-filling into a valley-polarized state, which realizes a correlated quantum anomalous Hall state with Chern number C=±2. Effects of displacement fields are discussed with comparison to nontrivial topology from layer-pseudospin magnetic fields.

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Phys. Rev. Research 4, L012032– Published 16 March, 2022
  • Received 2 July 2021
  • Revised 28 February 2022
  • Accepted 2 March 2022
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