Thermal gradient driven spin current in BN co-doped ferromagnetic zigzag graphene nanoribbons

Abstract

Abstract Based on first principles calculations, we investigate thermal spin transport in a zigzag graphene nanoribbon (ZGNR) device with B and N atoms doped at the opposite edges. It is found that by applying a thermal gradient without a bias voltage across the BN co-doped ZGNR device, spin-up and spin-down charge currents flowing in opposite directions are induced, leading to spin current. Specifically, a giant Seebeck thermopower with opposite signs for the two spin channels is obtained in the linear response regime and the magnitude is dependent on the doping concentration. More importantly, by slightly tuning the chemical potential, pure spin current can be achieved. These findings suggest a feasible way for producing thermal spin current in ZGNRs and will be greatly instructive in the design of graphene based spintronic devices.