Twist angle engineering of proximity exchange in graphene/Cr₂Ge₂Te₆ bilayers

Van der Waals heterostructures composed of twisted monolayers promise great tunability of electronic, optical, and magnetic properties. In this talk we present the twist-angle and gate dependence of the proximity exchange coupling in graphene/Cr$_2$Ge$_2$Te$_6$ bilayers from first principles. The proximitized Dirac band dispersions of graphene show a continuous tunability of the ferromagnetic exchange from positive 4 to negative -4 meV, when twisting from 0 to 30 degrees. Remarkably, at around 19 degrees the induced exchange coupling can become antiferromagnetic. Further tuning is provided by a transverse electric field and the interlayer distance.