论文标题
扭曲的三层石墨烯中的镜子对称性断裂和横向堆叠变化
Mirror Symmetry Breaking and Lateral Stacking Shifts in Twisted Trilayer Graphene
论文作者
论文摘要
我们使用{\ IT i i i}密度功能理论计算的扭曲三层石墨烯的连续模型，并将其应用于解决扭曲的三层电子结构。我们的模型解释了现场能量的Moiré差异，在外层和层之间跳跃。我们专注于具有中间层扭曲的ABA石墨烯三层中存在的镜像对称性的作用。当层之间的位移字段应用在侧层相对于底层时，镜像对称性会故意丢失，并且在层之间的位移字段施加时。 We use two band structure characteristics that are directly relevant to transport measurements, the Drude weight and the weak-field Hall conductivity, and relate them via the Hall density to assess the influence of the accidental lateral stacking shifts currently present in all experimental devices on electronic properties, and comment on the role of the possible importance of accidental lateral stacking shifts for superconductivity in twisted trilayers.
We construct a continuum model of twisted trilayer graphene using {\it ab initio} density-functional-theory calculations, and apply it to address twisted trilayer electronic structure. Our model accounts for moiré variation in site energies, hopping between outside layers and within layers. We focus on the role of a mirror symmetry present in ABA graphene trilayers with a middle layer twist. The mirror symmetry is lost intentionally when a displacement field is applied between layers, and unintentionally when the top layer is shifted laterally relative to the bottom layer. We use two band structure characteristics that are directly relevant to transport measurements, the Drude weight and the weak-field Hall conductivity, and relate them via the Hall density to assess the influence of the accidental lateral stacking shifts currently present in all experimental devices on electronic properties, and comment on the role of the possible importance of accidental lateral stacking shifts for superconductivity in twisted trilayers.
