Perfect negative differential resistance, spin-filter and spin-rectification transport behaviors in zigzag-edged δ-graphyne nanoribbon-based magnetic devices

摘要

Many layered graphene and graphene-like two-dimensional carbon materials have been successively proposed in theory and experiment owing to their exceptional properties and potential applications. By employing the first-principles study, we find that a new graphene-like material, delta-graphyne, whose properties of the zigzag-edged nanoribbon are very similar to those ones of zigzag-edged graphene case. The band structure clearly exhibits a metallic property in non-magnetic state. And we can see a visible spin splitting within the ferromagnetic state, however, spin degeneracy within the antiferromagnetic state. To this end, here we propose a molecular junction based on the zigzag-delta-graphyne nanoribbon symmetrically with additional phenyl rings at both edges. The computational results imply that the device has many good electron transport performances, such as negative differential resistance, spin-filtering and rectification effects, and so on. In particular, the spin-filtering efficiency can be up to 99%, and the maximum of the rectification ratio reaches up to 10(6)%. The mechanisms for these effects are revealed and discussed in terms of the band structure, spin-resolved electron transmission spectrum, the local density of state and the transmission pathway. Therefore, our research results can provide a basis for the experimental preparation of the delta-graphyne-based junction.