title: Effects of nonmagnetic impurities on the spin transport property of a graphene nanoribbon device.
abstract: Using a nonequilibrium density functional calculation, we investigated the electronic transport properties and fundamental mechanism of spin polarization as a function of the location of impurities from the center to an edge of a graphene nanoribbon device (GND) with zigzag edges. A center-located impurity enables both edges to be enhanced with respect to their spin transports whereas an edge-located impurity results in only the opposite edge channel being dominant. In the case of a center-located impurity, the ferromagnetic ground state induces new spin states near the Fermi level responsible for the spin-polarized current in the GND. We argue that the spin-polarized current can flow through the edge states induced by a nonmagnetic impurity around the Fermi level, especially on a GND with a center-located impurity.
authors.affiliation: Department of Chemistry, School of Molecular Science, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea.
authors.forename: Joonho
authors.initials: J
authors.lastname: Park
authors.forename: Heok
authors.initials: H
authors.lastname: Yang
authors.forename: K-S
authors.initials: KS
authors.lastname: Park
authors.forename: Eok-Kyun
authors.initials: EK
authors.lastname: Lee