單層二硫化鉬能帶結構的數值計算

Abstract

二硫化鉬近年來因其獨特的自旋及光電性質而備受科學家矚目[1,2,3]。在此論文中我使用多重能帶緊密束縛法[4]數值計算單層二硫化鉬的能帶特性。本工作揭示出二硫化鉬中強大的自旋軌道耦合效應導致電子自旋與valley強烈的關聯性和導帶與價帶的自旋劈裂。同時也模擬出各個Hopping term在二硫化鉬中的重要性，並與其它文獻比較後發現其它簡單模型的適用範圍。

Monolayer MoS2 has recently drawn a broad attention because of the intriguing spin and photonic features useful for advanced quantum applications in spin- or valley-tronics.[1,2,3] In this work, we carry out numerical computations of the band structures of monolayer MoS2 using tight binding approaches [4]. The employed tight-binding model takes the sp3d5 non-orthogonal basis in the LCAO method, where spin orbit couplings are taken into account. This study shows the spin of electron dependents on K-space because of the strong spin effect of MoS2, it also split valence and conduction band due to Mo and S respectively, SOC resulting in the splitting of valence-band and conduction-band at the energy scales 156meV and 20meV. We figure out the roles of each hopping terms in the resulting band structures, and make a comparison with other existing simplified models.