Spin filtering and large magnetoresistance behaviors in carbon chain-zigzag graphene nanoribbon nanojunctions

Using the non-equilibrium Green's function method combined with the density functional theory, we investigate the electron and spin transport properties of carbon chains covalently connected with zigzag-edged graphene electrodes at finite bias with the parallel (P) and antiparallel (AP) magnetism configurations. When two zigzag-edged graphene electrodes are H2-ZGNR-H structures, spin filtering effect can be realized only with AP magnetism configuration. While one electrode is replaced with the H-ZGNR-H structure, we observe a dual spin filtering effect with above two magnetism configurations. But the spin transport properties of carbon chains can also be affected by the linking way of the carbon chain ends. Deeper analyses show that the spin-related properties are related to the electrodes, magnetism configurations, and the connection structure between electrodes and carbon chains.