Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC, and BIST , Campus UAB , 08193 Barcelona , Spain.
QuantaLab & International Iberian Nanotechnology Laboratory (INL) , Av. Mestre José Veiga , 4715-330 Braga , Portugal.
Nano Lett. 2018 Mar 14;18(3):2033-2039. doi: 10.1021/acs.nanolett.7b05482. Epub 2018 Mar 2.
Enhancing the spin-orbit interaction in graphene, via proximity effects with topological insulators, could create a novel 2D system that combines nontrivial spin textures with high electron mobility. To engineer practical spintronics applications with such graphene/topological insulator (Gr/TI) heterostructures, an understanding of the hybrid spin-dependent properties is essential. However, to date, despite the large number of experimental studies on Gr/TI heterostructures reporting a great variety of remarkable (spin) transport phenomena, little is known about the true nature of the spin texture of the interface states as well as their role on the measured properties. Here, we use ab initio simulations and tight-binding models to determine the precise spin texture of electronic states in graphene interfaced with a BiSe topological insulator. Our calculations predict the emergence of a giant spin lifetime anisotropy in the graphene layer, which should be a measurable hallmark of spin transport in Gr/TI heterostructures and suggest novel types of spin devices.
通过与拓扑绝缘体的近邻效应增强石墨烯中的自旋轨道相互作用，可以创建一个新的二维系统，将非平凡的自旋纹理与高电子迁移率结合在一起。为了用这种石墨烯/拓扑绝缘体（Gr/TI）异质结构设计实用的自旋电子学应用，了解混合自旋相关性质是必不可少的。然而，迄今为止，尽管大量关于 Gr/TI 异质结构的实验研究报告了各种各样的显著（自旋）输运现象，但对于界面态的真实自旋纹理及其在测量性质中的作用知之甚少。在这里，我们使用从头算模拟和紧束缚模型来确定与 BiSe 拓扑绝缘体界面的石墨烯中电子态的精确自旋纹理。我们的计算预测了石墨烯层中巨大的自旋寿命各向异性的出现，这应该是 Gr/TI 异质结构中自旋输运的一个可测量标志，并提出了新型的自旋器件。
