Sign-changeable spin-filter efficiency and giant magnetoresistance in seamless graphene nanoribbon junctions

Sign-changeable spin-filter efficiency is predicted in both the ferromagnetic and antiferromagnetic configurations of a zigzag graphene nanoribbon bridging two half-planar graphene electrodes from ab initio quantum transport calculations. By changing edge spin-polarization configuration, we obtain giant room-temperature magnetoresistance, which is one order of magnitude larger than the maximum experimental results.

► Quantum transport properties of graphene nanoribbons are calculated.
► Graphene nanoribbons exhibit sign-changeable spin-filter efficiency.
► They also show high room-temperature magnetoresistance.