Metallic phase of disordered graphene superlattices with long-range correlations

摘要

Using the transfer-matrix method, we study the conductance of chiral particles through a monolayer graphene superlattice with long-range correlated disorder distributed on the potential of the barriers. Even though the transmission of the particles through a graphene superlattice with white-noise potentials is suppressed, the transmission is revived in a wide range of angles when the potential heights are long-range correlated with a power spectrum S(k) ~ 1/K~ β. As a result, the conductance increases with increasing correlation-exponent values giving rise to a metallic phase. We obtain a phase-transition diagram in which the critical correlation exponent depends strongly on the disorder strength and slightly on the energy of the incident particles. The phase transition, on the other hand, appears in all ranges of the energy from propagating to evanescent mode regimes.