论文标题
氮化硼扭曲双层的结构分类和对其堆叠依赖性电子结构的概述
Structural classification of boron nitride twisted bilayers and ab initio investigation of their stacking-dependent electronic structure
论文作者
论文摘要
自从启动Twistronics领域的超导扭曲的双层石墨烯的发现以来，MoiréSystems尚未停止表现出迷人的特性。我们证明，在给定的Moiré周期性中，有五个不同的堆叠量可以保留单层六边形对称性（即120 $^\ circ $的旋转的不变性），不仅在文献中进行了两次讨论。我们介绍了一些定义和命名法，这些定义和命名法明确地识别了具有订单-3旋转对称性的任何六角形双层的扭曲角度和堆叠序列。此外，我们采用密度函数理论来研究条带结构的演变，这是氮化硼双层硼五个堆叠序列中的每个旋转角的函数。我们表明，差距在任何角度和任何堆叠中都是间接的，并确定在同一堆叠序列中保守的特征，而与扭曲角度无关。
Since the discovery of superconductive twisted bilayer graphene which initiated the field of twistronics, moiré systems have not ceased to exhibit fascinating properties. We demonstrate that in boron nitride twisted bilayers, for a given moiré periodicity, there are five different stackings which preserve the monolayer hexagonal symmetry (i.e. the invariance upon rotations of 120$^\circ$) and not only two as always discussed in literature. We introduce some definitions and a nomenclature that identify unambiguously the twist angle and the stacking sequence of any hexagonal bilayer with order-3 rotation symmetry. Moreover, we employ density functional theory to study the evolution of the band structure as a function of the twist angle for each of the five stacking sequences of boron nitride bilayers. We show that the gap is indirect at any angle and in any stacking, and identify features that are conserved within the same stacking sequence irrespective of the angle of twist.
