Controllable spin-dependent transport in the pristine graphene nanoribbons

Abstract

Based on the non-equilibrium Green’s function in combination with the density-functional theory, we investigate the spin-dependent electronic transport of graphene nanoribbon partially linked to two single Au atomic chains leads with symmetry and asymmetry structures. For symmetry structures, the spin-dependent electronic transports are spin degeneracy, but for asymmetry structures, the spin degeneracy will be broken, leading to high spin polarization. So the spin-polarized transport can be controlled simply by adjusting connection structure between leads and graphene nanoribbon ends. Deeper analyses indict that the spin-dependent transport behaviours can be interpreted by the magnetic moments and the local density of state (LDOS).