论文标题
三个符号：在过渡金属二分裂基质边界处的自旋/电荷密度波
The Sign of Three: Spin/Charge Density Waves at the Boundaries of Transition Metal Dichalcogenides
论文作者
论文摘要
二维半导体{\ mx}（m = mo，w; x = s，se）的一维晶界通常在室温下在金属上是金属的。金属性起源于晶格偏振，对于这些带有$ d_ {3h} $对称性的晶格是拓扑不变的，并导致频带间隙内的一维边界状态。对于垂直于极化方向的边界，这些状态必然会由电子或孔占据1/3，使其容易受到翻译时期三倍的金属构造物过渡的影响。使用密度功能理论计算，我们证明了边界处该时期的一维自旋密度/电荷密度波的出现，从而打开了$ \ sim 0.1 $ ev的小带隙。这种独特的电子结构允许在边界处进行孤子激发，该边界带有$ \ pm 1/3 \ e $的分数电荷。
One-dimensional grain boundaries of two-dimensional semiconducting {\MX} (M= Mo,W; X=S,Se) transition metal di-chalcogenides are typically metallic at room temperature. The metallicity has its origin in the lattice polarization, which for these lattices with $D_{3h}$ symmetry is a topological invariant, and leads to one-dimenional boundary states inside the band gap. For boundaries perpendicular to the polarization direction, these states are necessarily 1/3 occupied by electrons or holes, making them susceptible to a metal-insulator transition that triples the translation period. Using density-functional-theory calculations we demonstrate the emergence of combined one-dimensional spin density/charge density waves of that period at the boundary, opening up a small band gap of $\sim 0.1$ eV. This unique electronic structure allows for soliton excitations at the boundary that carry a fractional charge of $\pm 1/3\ e$.
