论文标题
双层石墨烯中的非相同Moiré双胞胎
Non-identical moiré twins in bilayer graphene
论文作者
论文摘要
通过将单层石墨烯和氮化硼（BN）对齐获得的超晶格从六十度的周期性与层对齐的六十度周期性继承。它意味着，原则上，对于0 $^{\ circ} $和层对齐的60 $^{\ circ} $，异质结构的属性必须相同。在这里，我们使用动态旋转的Van der waals异质结构证明，在双层石墨烯/bn中形成的Moiré超级晶格具有不同的电子属性，该属性在0 $^{\ circ} $和60 $^{\ circ} $时。尽管这些非相同的莫伊尔双胞胎的存在是通过对每种比对的原子结构的不同放松来解释的，但观察到的山谷大厅效应的起源仍有待解释。一个简单的浆果曲率论点不能解释该观察结果的一百二十度周期性。我们的结果突出了机械性能和电子特性在Moiré结构上的相互作用的复杂性，以及考虑原子结构松弛以了解其电子特性的重要性。
The superlattice obtained by aligning a monolayer graphene and boron nitride (BN) inherits from the hexagonal lattice a sixty degrees periodicity with the layer alignment. It implies that, in principle, the properties of the heterostructure must be identical for 0$^{\circ}$ and 60$^{\circ}$ of layer alignment. Here, we demonstrate, using dynamically rotatable van der Waals heterostructures, that the moiré superlattice formed in a bilayer graphene/BN has different electronic properties at 0$^{\circ}$ and 60$^{\circ}$ of alignment. Although the existence of these non-identical moiré twins is explained by different relaxation of the atomic structures for each alignment, the origin of the observed valley Hall effect remains to be explained. A simple Berry curvature argument do not hold to explain the hundred and twenty degrees periodicity of this observation. Our results highlight the complexity of the interplay between mechanical and electronic properties on moiré structure and the importance of taking into account atomic structure relaxation to understand its electronic properties.
