Perfect spin-filter and negative differential resistance for a carbon chain device with defective graphene nanoribbons connected

In order to study the characteristics of carbon chains and defects in graphene nanoribbons, we studied the electronic transport characteristics for a carbon chain device with defective graphene nanoribbon connected. And density functional theory (DFT) combined with the non-equilibrium green's function (NEGF) is used as the research method. By analyzing the calculations, we found this structure has an excellent spin filtering effect. Meanwhile, we also observed the spin-up current has a negative differential resistance effect (NDR) at a low negative bias. The spin filter and NDR are simultaneously observed in a carbon-based device, which has great significance in spintronic research.