Abstract
In this talk, I will discuss recent theoretical progress on the insulating phase at ν=3 discovered in twisted bilayer graphene. While experiments discovered this phase is topologically trivial, most theoretical calculations obtain either the metallic state with nodes or the quantum anomalous Hall state that is gapped but topologically nontrivial. In this talk, I will present both the analytical and numerical evidence for the stripe phase at ν=3, and discuss how the nodes can be annihilated by braiding and lead to a trivial insulating state.
References:
1. J Kang and O Vafek, Phys. Rev. Lett., 122, 246401 (2019).
2. J Kang and O Vafek, Phys. Rev. B, 102, 035161 (2020).
3. F Xie, J Kang, BA Bernevig, O Vafek, and N Regnault, Phys. Rev. B 107, 075156 (2023).
This event is organized by the HKU-UCAS Joint Institute of Theoretical and Computational Physics and HK Institute of Quantum Science & Technology