论文标题
基于TIX2（X = TE，S和SE）异质结构中Rashba效应和自旋valley耦合的共存
Coexistence of Rashba Effect and Spin-valley Coupling in TiX2 (X= Te, S and Se) based Heterostructures
论文作者
论文摘要
自旋轨道耦合（SOC）与破裂的反转对称性在诱导Rashba效应中起关键作用。合并的自发极化和RASHBA效应可以通过电力控制材料的自旋度。在这项工作中，我们研究了TIX2单层（X = TE，S和SE）的多种组合的电子带结构：Tite2/Tise2，Tite2/Tis2和Tise2/Tis2。基于这些异质结构（HSS）中不同单层之间观察到的轨道杂交，我们得出结论，最显着的RASHBA分裂发生在TISE2/TIS2中。随后，我们将氟（F）用作空心和表面顶部位点的TISE2/TIS2表面上的Adatom来增强Rashba强度，因为F ADATOM由于电荷分布的差异而引起极化。此外，通过增加表面上的F原子的数量，我们加强了频带分裂，即，我们观察到Rashba分裂，伴随着Zeeman在Valence-Band边缘状态下分裂。具有相等和相反性质的K和K'的浆果曲率证实了山谷极化的存在。计算观察到的特性表明，这些HSS是Spin-Valley Hall效应设备和其他Spintronic应用的有希望的候选者。
Spin-orbit coupling (SOC) combined with broken inversion symmetry play key roles in inducing Rashba effect. The combined spontaneous polarization and Rashba effect enable controlling a material's spin degrees of freedom electrically. In this work we investigated the electronic band structure for several combinations of TiX2 monolayers (X= Te, S and Se): TiTe2/TiSe2, TiTe2/TiS2, and TiSe2/TiS2. Based on the observed orbital hybridization between the different monolayers in these hetero-structures (HSs), we conclude that the most significant Rashba splitting occurs in TiSe2/TiS2. Subsequently, we used Fluorine (F) as an adatom over the surface of TiSe2/TiS2 at hollow and top sites of the surface to enhance the Rashba intensity, as the F adatom induces polarization due to difference in charge distribution. Furthermore, by increasing the number of F atoms on the surface, we reinforced the band splitting, i.e., we observe Rashba splitting accompanied by Zeeman splitting at the valence-band edge states. Berry curvatures at K and K' with equal and opposite nature confirms the existence of valley polarization. The computationally observed properties suggest that these HSs are promising candidates for spin-valley Hall effect devices and other spintronic applications.
