Switching modulation of spin transport in ferromagnetic tetragonal silicene

• Published in: arXiv.org 2022-07
• Main Authors: Liao, Liehong, Ding, Ying, Wan, Fei, Zhang, Jiayan, Chen, Zhihui, Cheng, Xinyu, Bai, Ru, Xu, Gaofeng, Li, Yuan
• Format: Article
• Language: English
• Subjects: Band structure of solids; Electric fields; Ferromagnetism; Green's functions; Nanoribbons; Phase transitions; Polarization (spin alignment); Potential barriers; Potential energy; Separation; Silicene; Spin-orbit interactions; Spintronics; Switches; Transport buildings, stations and terminals; Transport properties
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2207.12676

We study the band structure and transport properties of ferromagnetic tetragonal silicene nanoribbons by using the non-equilibrium Green's function method. The band structure and spin-dependent conductance are discussed under the combined effect of the external electric field, potential energy, exchange field and the spin-orbit coupling. One can easily realize a phase transition from a semimetallic to a semiconducting state by changing the transverse width of the nanoribbon. Separation of spin-dependent conductances arises from the effect of exchange field and the spin-orbit coupling, while zero-conductance behaviors exhibit spin-dependent band gaps induced by the electric field. We propose a device configuration of four-terminal tetragonal silicene nanoribbon with two central channels. It is found that spin current can be controlled by utilizing two switches. The switch with a high potential barrier can block electrons flowing from the central scattering region into other terminals. Interestingly, applying only one switch can realize spin-dependent zero conductance and large spin polarization. Two switches can provide multiple operations for controlling spin-dependent transport properties. The two-channel ferromagnetic tetragonal silicene nanoribbon can realize an effective separation of spin current, which may be a potential candidate for spintronic devices.