Selection rules of twistronic angles in two-dimensional material flakes via dislocation theory
Selection rules of twistronic angles in two-dimensional material flakes via dislocation theory
复制标题
基于位错理论的二维材料片中扭转角的选择规则
DOI：
10.1103/physrevb.103.115427
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发表时间：
2021
影响因子：
3.7
通讯作者：
Johnson, Harley T.
中科院分区：
文献类型：
--
作者：
Zhu, Shuze;Annevelink, Emil;Pochet, Pascal;Johnson, Harley T.
层间旋转角度与扭曲范德华层的电子态强烈耦合。然而，并非每个角度在能量上都是有利的。最近关于旋转可调电子器件的实验揭示了一组离散角度的存在，在这些角度下，旋转可调电子器件呈现最稳定的配置。然而，目前还没有用于在扭曲双层系统中定位这些本质上优选的扭曲角度的定量图，这对在所需扭曲角度下本质上稳定的扭曲电子器件的按需设计提出了挑战。在这里，我们揭示了本质上优选的扭曲角和扭曲双层系统的几何形状之间的简单映射，其形式为各种本质上优选的扭曲角的几何缩放定律，仅作为支撑层上旋转薄片的几何参数的函数。我们揭示了三角形和六边形薄片的这些缩放定律，因为它们经常出现在化学气相沉积生长中。我们还提出了一种处理任意薄片几何形状的通用方法。这种无量纲标度定律对各种二维材料双层系统具有普适性，为内在“双电子学”的按需设计提供了丰富的机会。例如，可以揭示在双层石墨烯系统中本质上更喜欢多个魔角的零逼近序列的一组增加的魔尺寸。
Interlayer rotation angles couple strongly to the electronic states of twisted van der Waals layers. However, not every angle is energetically favorable. Recent experiments on rotation-tunable electronics reveal the existence of a discrete set of angles at which the rotation-tunable electronics assume the most stable configurations. Nevertheless, a quantitative map for locating these intrinsically preferred twist angles in a twisted bilayer system has not been available, posing challenges for the on-demand design of twisted electronics that are intrinsically stable at desired twist angles. Here we reveal a simple mapping between intrinsically preferred twist angles and the geometry of the twisted bilayer system, in the form of geometric scaling laws for a wide range of intrinsically preferred twist angles as a function of only geometric parameters of the rotating flake on a supporting layer. We reveal these scaling laws for triangular and hexagonal flakes since they frequently appear in chemical vapor deposition growth. We also present a general method for handling arbitrary flake geometry. Such dimensionless scaling laws possess universality for all kinds of two-dimensional material bilayer systems, providing abundant opportunities for the on-demand design of intrinsic “twistronics.” For example, the set of increasing magic sizes that intrinsically prefer a zero-approaching sequence of multiple magic angles in a bilayer graphene system can be revealed.