Spin-polarized electric current in silicene nanoribbons induced by atomic adsorption

TL;DR

This paper explores how atomic adsorption on silicene nanoribbons induces spin-polarized electric currents through a spin-dependent Fano effect, offering potential applications in spintronics.

Contribution

It demonstrates the emergence of tunable spin-polarized conductance in silicene nanoribbons caused by adatom-induced Fano resonances, a novel mechanism for spintronics.

Findings

Full spin polarization achieved in a broad energy window.

Fano antiresonances depend on spin orientation.

Atomic adsorption induces spin-dependent conductance features.

Abstract

We investigate the nonequilibrium transport properties of a silicene armchair nanoribbon with a random distribution of adsorbed atoms in apex positions. A ferromagnetic insulator grown below the nanoribbon splits spin-up and spin-down electron bands and gives rise to a spin polarization of the conductance. The conductance vanishes when the Fermi energy matches the adatom levels due to the coupling of adatom localized states with the continuum spectra of the nanoribbon. This is the well-known Fano effect, resulting in a spin-dependent antiresonance in the conductance. The different antiresonance energies of spin-up and spin-down electrons give rise to a full spin polarization of the conductance in a broad energy window. This spin-dependent Fano effect opens the possibility to using it in spintronics as a tuneable source of polarized electrons.