Perfect optical spin-filtering in antiferromagnetic stanene nanoribbons induced by band bending and uniaxial strain

TL;DR

This paper theoretically investigates how electric fields, polarized light, band bending, and uniaxial strain influence spin-polarized transport in antiferromagnetic stanene nanoribbons, revealing conditions for efficient optical spin-filtering at room temperature.

Contribution

It introduces a comprehensive theoretical model demonstrating how combined electric, optical, and mechanical effects enable controllable spin filtering in stanene nanoribbons.

Findings

Band degeneracy splitting due to electric field enhances spin control.

Unequal photon absorption leads to spin-polarized photocurrents.

Band bending and strain extend the operational wavelength range.

Abstract

Non-equilibrium spin-polarized transport properties of antiferromagnetic stanene nanoribbons are theoretically studied under the combining effect of a normal electric field and linearly polarized irradiation based on the tight-binding model at room temperature. Due to the existence of spin-orbit coupling in stanene lattice, applying normal electric field leads to splitting of band degeneracy of spin-resolved energy levels in conduction and valence bands. Furthermore, unequivalent absorption of the polarized photons at two valleys which is attributed to an antiferromagnetic exchange field results in unequal spin-polarized photocurrent for spin-up and spin-down components. Interestingly, in the presence of band bending which has been induced by edge potentials, an allowable quantum efficiency occurs over a wider wavelength region of the incident light. It is especially important that the variation of an exchange magnetic field generates spin semi-conducting behavior in the bended band structure. Moreover, it is shown that optical spin-filtering effect is obtained under the simultaneous effect of uniaxial strain and narrow edge potential.