Fully Spin-Polarized Current In Gated Bilayer Silicene

By applying density functional theory calculations, we predict that the ground state of bilayer silicene at certain interlayer distances can be antiferromagnetic. At small electron or hole doping, it becomes half metallic under applied out-of-plane electric field, which can be used to produce a fully spin-polarized field-effect-driven current even in the absence of an external magnetic field, ferromagnetic substrates, doped magnetic ions, or spin-orbital coupling. Our finding points out a route to overcome the major challenge of spintronics.