二维IV-V族化合物中具有巨自旋劈裂的全区持续自旋织构
Full-zone Persistent Spin Textures with Giant Spin Splitting in Two-dimensional Group IV-V Compounds
摘要：
持久自旋织构（PST）是固态材料在动量$k$ -空间中保持单向自旋极化的性质，其提供了通过持久自旋螺旋（PSH）机制提供必要的长载流子自旋寿命的途径。然而，大多数发现的PST局部发生在第一布里渊区（FBZ）中某些高对称性$k$点或线周围的小部分中，从而限制了PSH状态的稳定性。本文通过对称性分析和第一性原理计算，报道了在二维IV-V族$A_{2}B_{2}$（$A$ = Si，Sn，Ge; $B$ = Bi，Sb）化合物中出现了全带PST（FZPST），这是一种在整个FBZ中显示PST的现象。由于任意$\vec{k}$在整个FBZ中存在波矢点群对称的面内镜像对称操作，在$k$空间中观察到完全的面外自旋极化，从而维持FZPST.重要的是，我们观察到巨大的自旋分裂，其中PST维持，支持大SOC参数和小波长的PSH状态。我们的$\vec{k}\cdot\vec{p}$分析表明，FZPST是强大的非简并带，这可以通过施加一个外部电场有效地控制，从而为未来的自旋电子学应用提供了一个有前途的平台。
英文摘要：
Persistent spin texture (PST), a property of solid-state materials maintaining unidirectional spin polarization in the momentum $k$-space, offers a route to deliver the necessary long carrier spin lifetimes through the persistent spin helix (PSH) mechanism. However, most of the discovered PST locally occurred in the small part around certain high symmetry $k$-points or lines in the first Brillouin zone (FBZ), thus limiting the stability of the PSH state. Herein, by symmetry analysis and first-principles calculations, we report the emergence of full-zone PST (FZPST), a phenomenon displaying the PST in the whole FBZ, in the two-dimensional group IV-V $A_{2}B_{2}$ ($A$ = Si, Sn, Ge; $B$ = Bi, Sb) compounds. Due to the existence of the in-plane mirror symmetry operation in the wave vector point group symmetry for the arbitrary $\vec{k}$ in the whole FBZ, fully out-of-plane spin polarization is observed in the $k$-space, thus maintaining the FZPST. Importantly, we observed giant spin splitting in which the PST sustains, supporting large SOC parameters and small wavelengths of the PSH states. Our $\vec{k}\cdot\vec{p}$ analysis demonstrated that the FZPST is robust for the non-degenerate bands, which can be effectively controlled by the application of an external electric field, thus offering a promising platform for future spintronic applications.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
