Gate voltage induced spin-filtering effect in a junction based on zigzag graphene nanoribbons

Abstract

The spin polarized electronic transport in a junction based on ferromagnetic (FM) zigzag graphene nanoribbons (ZGNRs) is investigated by means of the non-equilibrium Green function technique within the mean field Hubbard model. By applying a step-like potential, the spin polarized current can be got, since the band structures of two spin states in FM ZGNRs are non-degenerate and the coherent electron transport obeys the band selective rule. The junction works as a spin-filter and the spin-filtering efficiency can reach the value 100%.