论文标题
霍夫史塔特蝴蝶和金属/绝缘子过渡，用于莫伊尔异质结构
Hofstadter butterflies and metal/insulator transitions for moiré heterostructures
论文作者
论文摘要
我们考虑了Timmel和Mele最近引入的紧密结合模型，用于紧张的Moiré异质结构。我们考虑了两个蜂窝晶格，将层的反对称剪切应变应用于一个划分的晶格之间的隧道，以一个杰出的方向调节隧道。这有效地将模型降低到一个空间维度，并使其适合基质值的准周期运算符理论。然后，我们研究该系统的电荷传输和光谱特性，解释了Hofstadter型蝴蝶的出现以及最近已实验验证了用于非相互作用的Moiré系统的金属/绝缘体跃迁的发生。为了足够不可限的moiré长度，用二聚体条件描述，以及晶格之间的强耦合，可以通过施加物理压力来调整，这导致了定位现象的发生。
We consider a tight-binding model recently introduced by Timmel and Mele for strained moiré heterostructures. We consider two honeycomb lattices to which layer antisymmetric shear strain is applied to periodically modulate the tunneling between the lattices in one distinguished direction. This effectively reduces the model to one spatial dimension and makes it amenable to the theory of matrix-valued quasi-periodic operators. We then study the charge transport and spectral properties of this system, explaining the appearance of a Hofstadter-type butterfly and the occurrence of metal/insulator transitions that have recently been experimentally verified for non-interacting moiré systems. For sufficiently incommensurable moiré lengths, described by a diophantine condition, as well as strong coupling between the lattices, which can be tuned by applying physical pressure, this leads to the occurrence of localization phenomena.
