Construction of twisted graphene-silicene heterostructures

Van der Waals stacking of two-dimensional crystals with rotation or mismatch in lattice constants gives rise to rich physical phenomena that are closely related to the strong correlations and band topology. Twisted graphene and silicene heterobilayers have been theoretically predicted to host a tunable transport gap due to the mismatch of Dirac cones in the graphene and silicene layers. However, experimental realization of such twisted structure is challenging. Here, we report the formation of twisted graphene/silicene bilayers on Ru (0001) crystal via intercalation. Different moiré patterns form as single-crystalline graphene grows over different grains of the Ru surface. After silicon intercalation, graphene/silicene bilayers are observed with different twisting angles on top of different grains of the Ru substrate. Our work provides a new pathway towards construction of graphene based twisted heterobilayers.