title: Spatially separated spin carriers in spin-semiconducting graphene nanoribbons.
abstract: A graphene nanoribbon with sawtooth edges has a ferromagnetic ground state. Using first-principles and tight-binding model calculations, we show that, under a transverse electrical field, the sawtooth graphene nanoribbons become a spin semiconductor whose charge carriers are not only spin polarized in energy space but also spatially separated at different edges. Low-energy excitation produces spin-up electrons localized at one edge and spin-down holes at the opposite edge, and the excitation energy of spin carries can be tuned by the electric field to reach a new state of spin gapless semiconductor. Also, the spin semiconducting states are shown to be robust against at least 10% edge disorder. These features demonstrate a good tunability of spin carriers for spintronics applications.
authors.affiliation: Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, USA.
authors.forename: Z F
authors.initials: ZF
authors.lastname: Wang
authors.forename: Shuo
authors.initials: S
authors.lastname: Jin
authors.forename: Feng
authors.initials: F
authors.lastname: Liu