论文标题
河谷Zeeman效应和Landau水平二维过渡金属二分法生元素
Valley Zeeman effect and Landau levels in Two-Dimensional Transition Metal Dichalcogenides
论文作者
论文摘要
本文使用luttinger-kohn近似与旋转轨耦合有关，对二维H期H-相过渡金属二色染料（TMD）介绍了山谷Zeeman效应（G-Factor）和Landau水平的理论描述。在TMD的山谷极端，能量带分为Landau水平，在存在均匀的平面外部磁场的情况下，Zeeman移动。 Landau级别的指数在$ K $和$ k'$ valleys中对称。我们开发了一种数值方法来从第一原理中计算单个频段G因子，而无需超过无置频段的总和。多体效应在GW近似中被扰动。与从密度函数理论获得的相比，GW计算中非本地交换和相关自我能量效应增加了单个带G因子的幅度。我们的第一个原则结果与最近的光学实验一致，使自旋和山谷分裂的兰道水平具有旋转和山谷分裂的水平。在这项工作中推出的激子G因素也与单层WSE $ _2 $的明亮和深色激子的实验以及Mose $ _2 $ -WSE $ -WSE $ _2 $ HETEROBILAYER的最低能源明亮的激子的实验非常吻合。
This paper presents a theoretical description of both the valley Zeeman effect (g-factors) and Landau levels in two-dimensional H-phase transition metal dichalcogenides (TMDs) using the Luttinger-Kohn approximation with spin-orbit coupling. At the valley extrema in TMDs, energy bands split into Landau levels with a Zeeman shift in the presence of a uniform out-of-plane external magnetic field. The Landau level indices are symmetric in the $K$ and $K'$ valleys. We develop a numerical approach to compute the single band g-factors from first principles without the need for a sum over unoccupied bands. Many-body effects are included perturbatively within the GW approximation. Non-local exchange and correlation self-energy effects in the GW calculations increase the magnitude of single band g-factors compared to those obtained from density functional theory. Our first principles results give spin- and valley-split Landau levels, in agreement with recent optical experiments. The exciton g-factors deduced in this work are also in good agreement with experiment for the bright and dark excitons in monolayer WSe$_2$, as well as the lowest-energy bright excitons in MoSe$_2$-WSe$_2$ heterobilayers with different twist angles.
