Multiorbital edge and corner states in black phosphorene
Multiorbital edge and corner states in black phosphorene
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DOI：
10.1103/physrevb.104.125302
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发表时间：
2021-05
影响因子：
3.7
通讯作者：
Masaru Hitomi;T. Kawakami;M. Koshino
中科院分区：
文献类型：
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作者：
Masaru Hitomi;T. Kawakami;M. Koshino
我们从理论上研究了单层黑磷烯中的边角局域态。利用基于密度泛函理论的紧束缚模型，我们发现非平面褶皱几何所导致的多轨道能带结构在边界局域模的形成中起着至关重要的作用.特别地，我们证明了边缘态出现在沿着任意晶体学方向的边界处，并且可以从与3px，3py，3pz轨道相关的Wannier轨道占据磷烯的所有键中心的事实来理解。在两条边相交的角上，我们发现由于高阶拓扑角态和附近的边态的杂化，出现了多个角局域态。这些特征性质的边缘和角落的状态可以直观地解释了一个简单的拓扑等价模型，其中所有的键角变形到90 °。
We theoretically study emergent edge/corner localized states in monolayer black phosphorene. Using the tight-binding model based on the density functional theory, we find that the multi-orbital band structure due to the non-planar puckered geometry plays an essential role in the formation of the boundary localized modes. In particular, we demonstrate that edge states emerge at a boundary along an arbitrary crystallographic direction, and it can be understood from the fact that the Wannier orbitals associated with 3px , 3py , 3pz orbitals occupy all the bond centers of phosphorene. At a corner where two edges intersect, we show that multiple corner-localized states appear due to hybridization of higher-order topological corner state and the edge states nearby. These characteristic properties of the edge and corner states can be intuitively explained by a simple topologically-equivalent model where all the bond angles are deformed to 90◦.