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.

19 pages, 13 figures

References in corpus (17)

• Lattice relaxation and energy band modulation in twisted bilayer graphenes
• Origin of band gaps in graphene on hexagonal boron nitride
• Imaging orbital ferromagnetism in a moiré Chern insulator
• Band structure and insulating states driven by the Coulomb interaction in twisted bilayer graphene
• Efficient simulation of moire materials using the density matrix renormalization group
• Gauge-Fixed Wannier Wave-Functions for Fractional Topological Insulators
• Moiré Commensurability and the Quantum Anomalous Hall Effect in Twisted Bilayer Graphene on Hexagonal Boron Nitride
• Adiabatic continuation of Fractional Chern Insulators to Fractional Quantum Hall States
• Nematic Valley Ordering in Quantum Hall Systems
• Hybrid Wannier Chern bands in magic angle twisted bilayer graphene and the quantized anomalous Hall effect
• Spontaneous Layer-Pseudospin Domain Walls in Bilayer Graphene
• Interacting multi-channel topological boundary modes in a quantum Hall valley system
• Excitonic Laughlin States in Ideal Topological Insulator Flat Bands and Possible Presence in Moiré Superlattice Materials
• Symmetry breaking in the double moiré superlattices of relaxed twisted bilayer graphene on hexagonal boron nitride
• Current Driven Magnetization Reversal in Orbital Chern Insulators
• Generalizing Quantum Hall Ferromagnetism to Fractional Chern Bands
• Charge and spin textures of Ising quantum Hall ferromagnet domain walls

Cited by in corpus (20)

• Imaging orbital ferromagnetism in a moiré Chern insulator
• Imaging Chern mosaic and Berry-curvature magnetism in magic-angle graphene
• Magic-angle helical trilayer graphene
• 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
• Atomistic theory of moiré Hofstadter's butterfly in magic-angle graphene
• Textured Exciton Insulators
• 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