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

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 نشر من قبل Glenn Wagner
 تاريخ النشر 2020
  مجال البحث فيزياء
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We consider magic-angle twisted bilayer graphene (TBG) at filling $ u=+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 moire systems. We comment on the implications of these results for transport and scanning probe experiments.



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