Friction by Shear Deformations in Multilayer Graphene

We present accurate calculations of friction in graphene films in configurations simulating the presence of an anchoring substrate. We find that a slider induces both out-of-plane and shear deformations, which increase with the thickness of the supported film. We elucidate the new frictional mechanism connected to shear layer motions, which is minimal for systems with the smallest number of layers.