论文标题
在二维非符号壁纸组晶格中可调的零点
Tunable Dirac points in a two-dimensional non-symmorphic wallpaper group lattice
论文作者
论文摘要
非晶状体对称性保护晶格系统中的dirac节点线和锥体。在这里，我们研究了属于非晶状体基团的二维晶格的光谱特性。具体而言，我们看着人字形晶格，其特征是两组在两个正交方向上应用的滑行对称性。我们使用包含水平和垂直跳跃术语的最接近邻居紧密结合模型来描述系统。我们在高对称路径的第一个布里鲁因区域内发现了两个非等效的狄拉克锥。我们通过使用现场电势破坏晶格对称性来调整这些狄拉克锥的位置。这些狄拉克锥可以合并成半迪拉克锥或沿高对称路径展开。最后，我们通过应用跳跃术语的二聚化来扰动系统。我们报告了描述准氧化曲线的第一个布里鲁因区域内的狄拉克锥流。我们介绍了放置在Cu（111）表面顶部的CO原子方面的实现。
Non-symmorphic symmetries protect Dirac nodal lines and cones in lattice systems. Here, we investigate the spectral properties of a two-dimensional lattice belonging to a non-symmorphic group. Specifically, we look at the herringbone lattice, characterised by two sets of glide symmetries applied in two orthogonal directions. We describe the system using a nearest-neighbour tight-binding model containing horizontal and vertical hopping terms. We find two non-equivalent Dirac cones inside the first Brillouin zone along a high-symmetry path. We tune these Dirac cones' positions by breaking the lattice symmetries using onsite potentials. These Dirac cones can merge into a semi-Dirac cone or unfold along a high-symmetry path. Finally, we perturb the system by applying a dimerization of the hopping terms. We report a flow of Dirac cones inside the first Brillouin zone describing quasi-hyperbolic curves. We present an implementation in terms of CO atoms placed on the top of a Cu(111) surface.
