1 research outputs found
Atomic carbon chains as spin-transmitters: an \textit{Ab initio} transport study
An atomic carbon chain joining two graphene flakes was recently realized in a
ground-breaking experiment by Jin {\it et al.}, Phys. Rev. Lett. {\bf 102},
205501 (2009). We present {\it ab initio} results for the electron transport
properties of such chains and demonstrate complete spin-polarization of the
transmission in large energy ranges. The effect is due to the spin-polarized
zig-zag edge terminating each graphene flake causing a spin-splitting of the
graphene bands, and the chain states. Transmission occurs when the
graphene -states resonate with similar states in the strongly hybridized
edges and chain. This effect should in general hold for any -conjugated
molecules bridging the zig-zag edges of graphene electrodes. The polarization
of the transmission can be controlled by chemically or mechanically modifying
the molecule, or by applying an electrical gate