Domain wall competition in the Chern insulating regime of twisted bilayer graphene

Abstract

We consider magic-angle twisted bilayer graphene (TBG) at filling $\nu =+3$, where experiments have observed a robust quantized anomalous Hall effect. This has been attributed to the formation of a valley- and spin-polarized Chern insulating ground state that spontaneously breaks time-reversal symmetry, and is stabilized by a hexagonal boron nitride (hBN) substrate. We identify three different types of domain wall, and study their properties and energetic selection mechanisms via theoretical arguments and Hartree-Fock calculations adapted to deal with inhomogeneous moiré systems. We comment on the implications of these results for transport and scanning probe experiments.

arXiv comment19 pages, 13 figures

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• Dynamical correlations and order in magic-angle twisted bilayer graphene
• Skyrmions in twisted bilayer graphene: stability, pairing, and crystallization
• Electron-phonon coupling and competing Kekulé orders in twisted bilayer graphene
• Evolution from quantum anomalous Hall insulator to heavy-fermion semimetal in magic-angle twisted bilayer graphene
• Kekulé spiral order at all nonzero integer fillings in twisted bilayer graphene
• Trions in Twisted Bilayer Graphene
• Angle-Tuned Gross-Neveu Quantum Criticality in Twisted Bilayer Graphene: A Quantum Monte Carlo Study
• Textured Exciton Insulators
• Atomistic theory of moiré Hofstadter's butterfly in magic-angle graphene
• Robust propagating in-gap modes due to spin-orbit domain walls in graphene
• Topological magnons and domain walls in twisted bilayer MoTe${}_2$
• Coulomb-driven band unflattening suppresses $K$-phonon pairing in moiré graphene
• Lattice Model For The Quantum Anomalous Hall Effect in Moiré Graphene
• Mean-field Modelling of Moiré Materials: A User's Guide with Selected Applications to Twisted Bilayer Graphene
• The emergence of interface states in graphene/transition metal dichalcogenides heterostructure with lateral interface
• Geometry-Driven Moiré Engineering in Twisted Bilayers of High-Pseudospin Fermions
• Doping-induced Quantum Anomalous Hall Crystals and Topological Domain Walls