Contribution of spin states to Seebeck coefficient of a single-layer zigzag graphene nanoribbons

Abstract We investigated the contribution of spin-up and spin-down states to the Seebeck coefficient in single-layer zigzag graphene nanoribbons. Firstly, we performed first-principles calculations to obtain the band energies which contain the energy dispersions of the spin-up and spin-down states. Here, we considered collinear ferromagnetic and antiferromagnetic edge states. From the obtained electronic structure, we employed the Boltzmann theory to extract the data of the Seebeck coefficient based on the spin-up and spin-down states. We found that each state gives different contributions to the peak of the Seebeck coefficient near the Fermi level. It suggested that the domination of each state for the Seebeck coefficient can be analyzed.