Sublattice Ferrimagnetism in Quasifreestanding Graphene

We show that graphene can be magnetized by coupling to a ferromagnetic Co film through a Au monolayer. The presence of dislocation loops under graphene leads to a ferrimagnetic ordering of moments in the two C sublattices. It is shown that the band gap of similar to 80 meV in the K point has a magnetic nature and exists for ferrimagnetic ordering. Interplay between Rashba and exchange couplings is evidenced by spin splitting asymmetry in spin-ARPES measurements and fully supported by DFT calculation of a (9 x 9) unit cell. Owing to sign-opposite Berry curvatures for K and K' valleys, the synthesized system is promising for the realization of a circular dichroism Hall effect.