Simulation of Graphene Nanoribbon Spin-Filter Device with Spin-Density Functional Tight-Binding Method

We study the spin filtering characteristics of the zigzag-edged graphene nanoribbon spin filtering device, applying the spin-density functional tight-binding method and the non- equilibrium Green's function method. Our simulations have shown that the spin filtering effect can be controlled by applying the side-gate voltages that effectively induce the transverse electric fields. Influence of an edge lattice vacancy on the spin- filtering effect is also discussed.