Abstract

We study the spin transport in a zigzag silicene nanoribbon (ZSNR) ferromagnetic junction with different even(odd)-chain widths and a perpendicular electric field on its drain electrode. By using the tight-binding lattice model and Keldysh Green’s function method, we calculate the spin-dependent transverse conductance and find that the spin switching effect always exists in the system regardless of the zigzag chain number is an even or an odd. The spin valve phenomena come from the combination of the even-odd chain effect and the perpendicular electric field induced energy gap. When a transmission electron flows from the left lead to the middle scattering region, the transport exhibits a peculiar even-odd chain effect, and then the electron may be prohibited to pass through the middle-right tunneling junction when a perpendicular electron field is applied on the right terminal. The spin transport in the proposed device can be controlled by almost all the system parameters such as Fermi energy, electric field, spin orbit coupling, ferromagnetic magnetization and width of the ZSNR. Furthermore, the proposed device might act as an electrical tunable spin valve to produce and detect a 100% polarized spin current.

Graphical abstract

中文翻译：

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之字形硅铁磁结中的奇偶链效应和垂直电场感应自旋阀

摘要

我们研究了锯齿形硅纳米带（ZSNR）铁磁结中的自旋输运，该结具有不同的偶数（奇数）链宽度和其漏极上的垂直电场。通过使用紧束缚网格模型和Keldysh Green函数方法，我们计算了自旋相关的横向电导，发现无论Z字形链数是偶数还是奇数，系统中始终存在自旋转换效应。自旋阀现象来自奇偶链效应和垂直电场感应能隙的结合。当传输电子从左引线流向中间散射区时，传输表现出奇偶奇数链效应，然后当在右端施加垂直电子场时，电子可能被禁止通过右中隧穿结。所提出的装置中的自旋输运几乎可以通过所有系统参数来控制，例如费米能量，电场，自旋轨道耦合，铁磁磁化强度和ZSNR的宽度。此外，所提出的装置可能充当电可调自旋阀，以产生和检测100％极化自旋电流。

图形概要