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Tuning correlated states of twisted mono-bilayer graphene with proximity-induced spin-orbit coupling

Jeyong Park1,2,*, Mingdi Luo1, Louk Rademaker3,4, Jurgen Smet1, Mathias S. Scheurer5, and Laura Classen1,2,†

  • *Contact author: jy.park@fkf.mpg.de
  • †Contact author: l.classen@fkf.mpg.de
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Phys. Rev. Research 8, 033225 – Published 24 August, 2026

DOI: https://doi.org/10.1103/xr1t-173x

Abstract

We study the correlated ground states of twisted mono-bilayer graphene with and without proximity-induced spin-orbit coupling (SOC) from a transition-metal dichalcogenide layer placed on top. We perform self-consistent Hartree-Fock calculations that allow the variational space to include multi-Q translational-symmetry-broken states for all integer and half-integer fillings of the conduction bands, where signatures of correlated, topological states have been reported experimentally. We find interaction-induced insulators that retain moiré translational symmetry at integer fillings, but that break this symmetry at half-integer fillings. We argue that translational symmetry breaking arises from half-filled polarized bands, even when SOC is present. Yet, we find that small SOC can already crucially affect the spin nature of correlated states. Generally, Ising SOC favors out-of-plane spin polarization and spin-valley locking, while Rashba SOC favors in-plane spin order. If only one of these two terms is present, we find that, depending on the type of SOC, it drives a transition from a tetrahedal antiferromagnet to either a coplanar, noncoplanar, or collinear spin-density wave state for half-integer fillings. The frustration associated with the simultaneous presence of both types of SOC can induce chiral, noncoplanar order in parameter ranges where the ground state in the absence of SOC is collinear.

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Phys. Rev. Research 8, 033225– Published 24 August, 2026
  • Received 17 March 2026
  • Accepted 16 July 2026
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