Abstract We investigate the production of spin-polarized currents in corrugated graphene nanoribbons. Such corrugations are modeled as multiple regions with Rashba spin-orbit interactions, where concave and convex curvatures are treated as Rashba regions with opposite signs. Numerical examples for different separated Rashba-zone geometries calculated within the tight-binding approximation are provided. Remarkably, the spin-polarized current in a system with several Rashba areas can be enhanced with respect to the case with a single Rashba part of the same total area. The enhancement is larger for configurations with multiple regions with the same Rashba sign. This indicates that the increase of the spin polarization is due to the scattering of the electrons traversing regions with and without Rashba interaction. Additionally, we relate the appearance of the spin-polarized currents to novel symmetry relations between the spin-dependent conductances. These symmetries turn out to be a combination of different symmetry operations in real and spin spaces, as those occurring in non-planar systems like carbon nanotubes. Our results show that two-dimensional devices with Rashba spin-orbit interaction can be used as excellent spintronic devices in an all-electrical or mechanical setup.

中文翻译：

---

波纹石墨烯纳米带中的自旋极化电流

摘要 我们研究了波纹石墨烯纳米带中自旋极化电流的产生。这种波纹被建模为具有 Rashba 自旋轨道相互作用的多个区域，其中凹曲率和凸曲率被视为具有相反符号的 Rashba 区域。提供了在紧束缚近似内计算的不同分离 Rashba 区几何形状的数值示例。值得注意的是，相对于具有相同总面积的单个 Rashba 部分的情况，可以增强具有多个 Rashba 区域的系统中的自旋极化电流。对于具有相同 Rashba 符号的多个区域的配置，增强作用更大。这表明自旋极化的增加是由于电子在有和没有 Rashba 相互作用的情况下穿过区域的散射。此外，我们将自旋极化电流的出现与自旋相关电导之间的新颖对称关系联系起来。事实证明，这些对称是实空间和自旋空间中不同对称操作的组合，就像在碳纳米管等非平面系统中发生的对称操作一样。我们的结果表明，具有 Rashba 自旋轨道相互作用的二维器件可用作全电气或机械装置中的优秀自旋电子器件。