Regular Article

Even-odd chain effect and perpendicular electric field induced spin valve in a zigzag silicene ferromagnetic junction

¹ Department of Applied Physics, College of Science, Nanjing Forestry University, Nanjing 210037, P.R. China
² Department of Physics and Institute of Theoretical Physics, Nanjing Normal University, Nanjing 210023, P.R. China
³ School of Physics and Electronic Engineering, Linyi University, Linyi 276005, P.R. China

^a e-mail: lzhang2010@163.com

Received: 27 January 2020
Published online: 27 April 2020

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.