▎ 摘　　要

We study spin transport in bilayer graphene structures where gate electrodes are attached to ferromagnetic graphene. Due to the exchange field in the gated regions, the current becomes spin dependent and can be controlled by tuning the gate voltages. It is shown that thanks to strong resonant chiral tunneling inherent in bilayer graphene, very high spin polarization and tunneling magnetoresistance can be achieved in the considered structures. Different possibilities for controlling the spin current are discussed. The study demonstrates the potential of bilayer graphene structures for spintronic applications with significant improvement over previously predicted results in monolayer graphene structures. (C) 2011 American Institute of Physics. [doi:10.1063/1.3569621]