Structure and Spin-Polarized Transport of Co Atomic Chains on Graphene with Topological Line Defects

We carry out density functional theory calculations to explore the nucleation growth of Co atoms absorbed on graphene with extended linear defect (LD@Gr). Based on the analysis of optimized structures, binding energies and diffusion barriers, we predict a patterned growth of linear arranged Co clusters along the LD. With the increase of cluster size, Co chain forms gradually and results in the construction of a quasi-one-dimensional (1D) heterostructure (Co/LD@Gr). Moreover, the transport properties of the Co/LD@Gr are investigated by using the non-equilibrium Green's function method combined with density functional theory. We find that the spin current paralleling to the LD is polarized. The spin-resolved transmission pathways and eigenchannels indicate that there is high spin injection from Co chain into graphene. As predetermined location and direction for the LD in graphene have been realized experimentally, this quasi-1D Co/LD@Gr heterostructure would be a compelling and feasible candidate for future spintronic related applications.