Chinese Physics B, Volume. 29, Issue 10, (2020)
Quantum anomalous Hall effect in twisted bilayer graphene quasicrystal
The nontrivial topology is investigated in a dodecagonal quasicrystal made of 30° twisted bilayer graphene (TBG). Based on tight-binding model with both exchange field and Rashba spin–orbit coupling, the topological index, chiral edge states, and quantum conductance are calculated to distinguish its unique topological phase. A high Bott index (B = 4) quantum anomalous Hall effect (QAHE) is identified in TBG quasicrystal, which is robust to a finite perturbation without closing the nontrivial gap. Most remarkably, we have found that the multiple Dirac cone replicas in TBG quasicrystal are only a spectra feature without generating extra chiral edge states. Our results not only propose a possible way to realize the QAHE in quasicrystal, but also identify the continuity of nontrivial topology in TBG between crystal and quasicrystal.
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Zedong Li, Z F Wang. Quantum anomalous Hall effect in twisted bilayer graphene quasicrystal[J]. Chinese Physics B, 2020, 29(10):
Received: May. 6, 2020
Accepted: --
Published Online: Apr. 21, 2021
The Author Email: Wang Z F (zfwang15@ustc.edu.cn)