论文标题
接口横向二维异质结构处的界面深色激子
Interface Dark Excitons at Sharp Lateral Two-Dimensional Heterostructures
论文作者
论文摘要
我们研究了二维过渡金属二核苷的尖锐侧面异质结构的界面上的深色激子。通过引入低能量有效的哈密顿模型，我们发现了激子的能量分散关系，并显示了它如何依赖组成材料的现场能量及其自旋轨道耦合强度。结果表明，在计算激子的结合能时，应考虑界面的几何结构作为变形规场（伪旋转轨道耦合）的影响。通过在三角形晶格上分配分散关系的真实空间版本，我们表明激子的结合能取决于其与接口线的距离。对于界面附近的激子，结合能等于0.36 eV，而对于离界面足够远的激子等于0.26 eV。同样，已经表明，对于锯齿形界面，与扶手椅界面相比，由于伪旋转 - 轨道相互作用（提交的规格），结合能与扶手椅界面相比增加了0.34 MeV。结果可用于设计基于二维侧面异质结构的光电设备并改善其特性。
We study the dark excitons at the interface of sharp lateral heterostructure of two-dimensional transition metal dichalcogenides. By introducing a low-energy effective Hamiltonian model, we find the energy dispersion relation of exciton and show how it depends on the onsite energy of composed materials and their spin-orbit coupling strengths. It is shown that the effect of geometrical structure of interface, as a deformation gauge field (pseudo-spin-orbit coupling), should be considered in calculating the binding energy of exciton. By discretization of real-space version of the dispersion relation on a triangular lattice, we show that the binding energy of exciton depends on its distance from the interface line. For exciton near the interface the binding energy is equal to 0.36 eV, while for the exciton enough far from the interface it is equal to 0.26 eV. Also, it has been shown that for zigzag interface the binding energy increases by 0.34 meV in comparison with the armchair interface due to the pseudo-spin-orbit interaction (gauge filed). The results can be used for designing the two-dimensional lateral heterostructure based optoelectronic devices and improving their characteristics.
