论文标题
单层PTSE $ _2 $
Intrinsic and extrinsic spin-orbit coupling and spin relaxation in monolayer PtSe$_2$
论文作者
论文摘要
单层PTSE $ _2 $是一种半导体的过渡金属二分裂基因，其特征是间接带隙，空间反转对称性和高载体迁移率。强烈的内在旋转轨道耦合以及通过门控诱导外部自旋轨道场的可能性使PTSE $ _2 $对基本旋转传输研究以及潜在的纺纱应用程序有吸引力。我们对这种材料中的自旋轨道耦合和自旋松弛进行了系统的理论研究。具体而言，我们采用第一原理方法来获得PTSE $ _2 $的基本轨道和自旋轨道特性，也是在外部横向电场的情况下。我们计算了旋转混合参数$ b^2 $和旋转轨道字段$ω$的电子和孔状态。由于Elliott-Yafet和D'Yakonov-Perel机制，这些信息使我们能够预测自旋寿命。我们发现$ b^2 $相当大，按$ 10^{ - 2} $和$ 10^{ - 1} $的订单，而$ω$随着兴奋剂而有很大差异，约为$ 10^{3} -10^{4} $ \ \，ns $^{ - 1} $ for％典型fermi $ in Intervel $ in Intervel $（10-100）（cristal）（10-100） $ 10^{13} -10^{14} $ \，cm $^{ - 2} $在1 V/nm的电场上。我们估计自旋寿命处于皮秒级。
Monolayer PtSe$_2$ is a semiconducting transition metal dichalcogenide characterized by an indirect band gap, space inversion symmetry, and high carrier mobility. Strong intrinsic spin-orbit coupling and the possibility to induce extrinsic spin-orbit fields by gating make PtSe$_2$ attractive for fundamental spin transport studies as well as for potential spintronics applications. We perform a systematic theoretical study of the spin-orbit coupling and spin relaxation in this material. Specifically, we employ first principles methods to obtain the basic orbital and spin-orbital properties of PtSe$_2$, also in the presence of an external transverse electric field. We calculate the spin mixing parameters $b^2$ and the spin-orbit fields $Ω$ for the Bloch states of electrons and holes. This information allows us to predict the spin lifetimes due to the Elliott-Yafet and D'yakonov-Perel mechanisms. We find that $b^2$ is rather large, on the order of $10^{-2}$ and $10^{-1}$, while $Ω$ varies strongly with doping, being about $10^{3} - 10^{4}$\,ns$^{-1}$ for %typical Fermi levels in the interval $(10-100)$ meV, carrier density in the interval $10^{13}-10^{14}$\,cm$^{-2}$ at the electric field of 1 V/nm. We estimate the spin lifetimes to be on the picosecond level.
