• Chinese Physics B
  • Vol. 29, Issue 10, (2020)
Zedong Li and Z F Wang
Author Affiliations
  • Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics, University of Science and Technology of China, Hefei 230026, China
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    DOI: 10.1088/1674-1056/abab77 Cite this Article
    Zedong Li, Z F Wang. Quantum anomalous Hall effect in twisted bilayer graphene quasicrystal[J]. Chinese Physics B, 2020, 29(10): Copy Citation Text show less

    Abstract

    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.
    H=Hu+Hl+Hint,(1)

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    Hu/l=t1ij,αciαcjα+tRij,αβ(\boldsymbolσ×\boldsymboldij)zciαcjβ+λi,αciαciα+h.c.,(2)

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    Hint=t2iup,αjlow,αciαcjαe3(rij3.35)+h.c.,(3)

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    P=i=1Nocc|ψiψi|,(4)

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    V1=Pei2πXP,V2=Pei2πYP,(5)

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    B=12πIm{Tr[log(VUVU)]}.(6)

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    G=e2hTr[ΓLGcrΓRGca],(7)

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    ΓL/R=i(ΣL/RrΣL/Ra),(8)

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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):
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