Schematic illustration of bilayer graphene-based normal/ferromagnetic/normal junction (a) where h₁ and h₂ are the exchange energies in the top and bottom layers, respectively. The spin-dependent energy levels in each region of the P-junction and spin-dependent energy levels in each region of the AP-junction are illustrated in panels (b) and (c), respectively. In the case of |h₁| = |h₂| = h = Δ_M, the spin-dependent gap is generated only when the junction is an AP-junction and there is no spin splitting.