Electronic properties of disordered bilayer graphene

Based on the Anderson tight-binding model, the electronic properties of disordered bilayer graphene are investigated. Our numerical results show that electrons in bilayer graphene with monolayer disorder (MDBG) exhibit a peculiar behavior that is quite different from that in bilayer graphene with bilayer disorder (BDBG). With the increase of disorder, BDBG becomes an insulating disordered two-dimensional (2D) electron system. In the case of monolayer disorder, however, the energy spectrum has strongly localized tail states and a stable extended central state separated by persistent mobility edges which are independent of the disorder strength. This indicates that a metal–insulator transition occurs in the monolayer disorder structure. This is similar to the case in an order–disorder separated quantum film. The results could offer useful information for understanding and manipulating the electronic properties of disordered bilayer graphene.