论文标题
测量扭曲双层石墨烯的本地Moiré晶格异质性
Measuring local moiré lattice heterogeneity of twisted bilayer graphene
论文作者
论文摘要
我们引入了一种新方法，以连续绘制Moiré晶格的不均匀性，并将其应用于我们在开放设备扭曲的双层石墨烯（TBG）上测量的大面积地形图像。我们表明，TBG设备的扭曲角度的变化通常被认为是具有类似扭曲角度的设备之间差异的原因，在几百nm面积的平均值约为2.02°附近约0.08°，可与HBN板之间封装的设备相当。我们区分有效的扭曲角度和局部各向异性，并将后者与异形相关联。我们的结果表明，对于我们的设备，扭曲角度异质性与局部应变具有大致相等的影响。此处介绍的方法适用于不同成像技术的结果以及不同的Moiré材料。
We introduce a new method to continuously map inhomogeneities of a moiré lattice and apply it to large-area topographic images we measure on open-device twisted bilayer graphene (TBG). We show that the variation in the twist angle of a TBG device, which is frequently conjectured to be the reason for differences between devices with a supposed similar twist angle, is about 0.08° around the average of 2.02° over areas of several hundred nm, comparable to devices encapsulated between hBN slabs. We distinguish between an effective twist angle and local anisotropy and relate the latter to heterostrain. Our results imply that for our devices, twist angle heterogeneity has a roughly equal effect to the electronic structure as local strain. The method introduced here is applicable to results from different imaging techniques, and on different moiré materials.
