Double Moire with a Twist: Supermoire in Encapsulated Graphene
Double Moire with a Twist: Supermoire in Encapsulated Graphene
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DOI：
10.1021/acs.nanolett.9b04058
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发表时间：
2020-02-01
期刊：
影响因子：
10.8
通讯作者：
Peeters, Francois M.
中科院分区：
文献类型：
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作者：
Andelkovic, Misa;Milovanovic, Slavisa P.;Peeters, Francois M.
为了设计和调整石墨烯的性质，人们对莫尔图案产生的周期性空间调制进行了广泛的研究。当六方氮化硼(HBN)包裹的石墨烯与上下hBN层稍有错位时，会经历两个干涉莫尔图案，从而产生所谓的超级莫尔(SM)。这导致了晶格和电子光谱的重建。非弛豫SM图案的几何结构使我们能够定性地表示电子性质的诱导变化，并在态密度和电导率中定位SM特征。为了强调晶格驰豫的影响，我们报道了重建光谱中空穴掺杂部分所有类狄拉克点的带隙，当考虑相互作用时，这些带隙有望得到增强。我们的结果能够区分晶格驰豫效应和干涉SM效应，并为最近实验观察到的这种三层异质结中效应的起源提供了清晰的图景。
A periodic spatial modulation, as created by a moire pattern, has been extensively studied with the view to engineer and tune the properties of graphene. Graphene encapsulated by hexagonal boron nitride (hBN) when slightly misaligned with the top and bottom hBN layers experiences two interfering moire patterns, resulting in a so-called supermoire (SM). This leads to a lattice and electronic spectrum reconstruction. A geometrical construction of the nonrelaxed SM patterns allows us to indicate qualitatively the induced changes in the electronic properties and to locate the SM features in the density of states and in the conductivity. To emphasize the effect of lattice relaxation, we report band gaps at all Dirac-like points in the hole doped part of the reconstructed spectrum, which are expected to be enhanced when including interaction effects. Our result is able to distinguish effects due to lattice relaxation and due to the interfering SM and provides a clear picture on the origin of recently experimentally observed effects in such trilayer heterostuctures.