Asymmetry engineering of spin-valley transport in bilayer silicene magnetic valves

We show asymmetry engineering as an effective approach to modulate spin-valley transport in bilayer silicene magnetic valves. Contrary to symmetric cases, our calculations for structure, magnetization, and field asymmetry engineering show that near-perfect spin and valley polarization are observed for magnetic valves in both parallel and antiparallel magnetization configurations, showing an expected tunneling magnetoresistance in the order of ${10}^{5}%$. Even with the structurally and magnetically symmetric magnetic valves, antisymmetric field can induce perfect polarization for spin states while valley-unpolarized or perfect polarization for valley states while spin-unpolarized. The perfect reversal between this pair can be simply achieved by reversing the magnetization configuration of magnetic valve, providing thus attractive strategies to code the spin-valley transport in bilayer silicene for spin-valleytronics applications.