Electronic band gaps and transport properties in graphene superlattices with one-dimensional periodic potentials of square barriers

The electronic transport properties and band structures for the graphene-based one-dimensional (1D) superlattices with periodic potentials of square barriers are investigated. It is found that a new Dirac point is formed, which is exactly located at the energy which corresponds to the zero (volume) averaged wave number inside the 1D periodic potentials. The location of such a new Dirac point is robust against variations in the lattice constant, and it is only dependent on the ratio of widths of the potential barriers. The zero-averaged wave-number gap associated with the new Dirac point is insensitive to both the lattice constant and the structural disorder and the defect mode in the zero-averaged wave-number gap is weakly dependent on the incident angles of carriers.