Spin-Resolved Transport Properties of a Pyridine-Linked Single Molecule Embedded between Zigzag-Edged Graphene Nanoribbon Electrodes

Abstract

We study the spin-dependent electron transport through a junction consisting of a single pyridine-linked (PDL) molecule sandwiched between two zigzag-edged graphene nanoribbon (ZGNR) electrodes modulated by an external magnetic field, where 4,4′-bipyridine, 4,4′-vinylenedipyridine, and 4,4′-ethylenedipyridine molecules are considered, respectively. By using ab initio calculations based on the density functional theory combined with nonequilibrium Green’s function formalism, it is shown that the spin-charge transport can be modulated by performing different magnetic configuration in the ZGNR electrodes. Specifically, we demonstrate that the proposed PDL molecular junctions exhibit several interesting effects, including (dual) spin-filtering, rectifying, negative differential resistance (NDR), and magnetoresistance. For the junction consisting of a 4,4′-bipyridine molecule with proper magnetic configuration in the two ZGNRs, it is interesting to note that a perfect spin polarization with filtering efficienc...