论文标题
Moiré上吐的NBSE $ _2 $ BiLayers中的上层建筑
Moiré Superstructures in Marginally-Twisted NbSe$_2$ Bilayers
论文作者
论文摘要
在二维晶体的扭曲双层中的Moiré超晶格的创建已被用来设计石墨烯和过渡金属二甲元素（TMD）半导体中的量子材料特性。在这里，我们检查了金属NBSE $ _2 $的小角度扭曲双层中的结构放松和电子特性。重建似乎对未对准角度$θ_p$ <2.9 $^o $和$θ_{ap} $ <1.2 $ <1.2 $^o $用于并行（p）和抗par的（ap）单层单元单元的方向。多尺度建模揭示了具有不同堆叠的域和域壁的形成，为此，密度功能理论（DFT）计算用于绘制双层费米表面的形状以及相邻层中CDW阶的相对相。我们发现，跨Moiré上层结构的层间耦合以及CDW相的首选层中取向的存在显着调制，因此需要在超级峰值域壁上CDW脱节的成核。
The creation of moiré superlattices in twisted bilayers of two-dimensional crystals has been utilised to engineer quantum material properties in graphene and transition metal dichalcogenide (TMD) semiconductors. Here, we examine the structural relaxation and electronic properties in small-angle twisted bilayers of metallic NbSe$_2$. Reconstruction appears to be particularly strong for misalignment angles $θ_P$ < 2.9$^o$ and $θ_{AP}$ < 1.2$^o$ for parallel (P) and antiparallel (AP) orientation of monolayers' unit cells, respectively. Multiscale modelling reveals the formation of domains and domain walls with distinct stacking, for which density functional theory (DFT) calculations are used to map the shape of the bilayer Fermi surface and the relative phase of the CDW order in adjacent layers. We find a significant modulation of interlayer coupling across the moiré superstructure and the existence of preferred interlayer orientations of the CDW phase, necessitating the nucleation of CDW discommensurations at superlattice domain walls.
