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arXiv · 2007.07903

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

Yves H. Kwan·Glenn Wagner·Nilotpal Chakraborty·Steven H. Simon·S. A. Parameswaran
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Abstract

We consider magic-angle twisted bilayer graphene (TBG) at filling $ν=+3$, 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.

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Yves H. Kwan, Glenn Wagner, Nilotpal Chakraborty, Steven H. Simon, S. A. Parameswaran. 2021-09-23. Domain wall competition in the Chern insulating regime of twisted bilayer graphene. https://doi.org/10.1103/physrevb.104.115404

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