Twisted van der Waals systems have emerged as intriguing arenas for exploring exotic strongly correlated and topological physics, with structural reconstruction and strain playing essential roles in determining their electronic properties. In twisted bilayer graphene aligned with hexagonal boron nitride (TBG/ℎ−BN), the interplay between the two sets of moiré patterns from graphene-graphene (𝐺−𝐺) and graphene–ℎ−BN (𝐺−ℎ−BN) interfaces can trigger notable moiré pattern reconstruction (MPR). Here, we present the quasiperiodic MPR in the TBG/ℎ−BN with two similar moiré wavelengths, wherein the MPR results from the incommensurate mismatch between the wavelengths of the 𝐺−𝐺 and 𝐺−ℎ−BN moiré patterns. The short-range, nearly ordered moiré super-superstructures deviate from moiré quasicrystal and are accompanied by inhomogeneous strain, thereby inducing spatially variable energy separations between the Van Hove singularities (VHs) in the band structures of the TBG near the magic angle. By tuning the carrier densities in our sample, correlated gaps at specific 𝐴⁢𝐴 sites are observed, uncovering the quantum-dot-like behavior and incoherent characteristics of the 𝐴⁢𝐴 sites in the TBG. Our findings would give new hints on the microscopic mechanisms underlying the abundant novel quantum phases in the TBG/ℎ−BN.

中文翻译：

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与六方氮化硼对位的扭曲双层石墨烯中的准周期莫尔重构和电子性能调制


扭曲的范德华系统已成为探索奇异的强相关和拓扑物理学的有趣领域，其中结构重建和应变在确定其电子特性方面起着至关重要的作用。在与六方氮化硼 （TBG/h-BN） 对齐的扭曲双层石墨烯中，来自石墨烯-石墨烯 （G-G） 和石墨烯-h-BN （G-h-BN） 界面的两组莫尔图案之间的相互作用可以触发显着的莫尔图案重建 （MPR）。在这里，我们以两个相似的莫尔波长表示 TBG/h-BN 中的准周期 MPR，其中 MPR 是由 G-G 和 G-h-BN 莫尔条纹波长之间不成比例的不匹配引起的。短程、近有序的莫尔超超结构偏离莫尔准晶，并伴有不均匀应变，从而在 TBG 的能带结构中靠近魔角的地方诱导空间可变能量分离。通过调整样本中的载流子密度，观察到特定 AA 位点的相关间隙，揭示了 TBG 中 AA 位点的量子点状行为和不相干特征。我们的发现将为 TBG/h−BN 中丰富的新量子相背后的微观机制提供新的提示。