Effects of short-range correlated disorder on the electronic transport of Fermi velocity graphene superlattices

Abstract

Random dimer graphene superlattices offer fertile ground to explore the effects of short-range correlated disorder and constitute an option to modulate the electronic transport in graphene. Here, we study the electronic transport in random dimer Fermi velocity graphene superlattices (RanDim-FVGSLs). The short-range correlated disorder is incorporated by having a certain percentage of quantum dimer barriers with a different value of the Fermi velocity with respect to the host superlattice structure. We also consider ordered (Ord) and disordered/not correlated (Ran) FVGSLs in order to compare the main characteristics of the electronic transport of RanDim-FVGSLs. A transmission scheme is used for the electronic transport. In particular, the transmission and the zero-temperature linear-regime conductance are obtained with the transfer matrix and the Landauer–Büttiker formalism, respectively. We find that depending on the percentage of correlated disorder and the ratio of Fermi velocities, an intermediate electronic transport between ordered and disordered superlattices is possible in RanDim-FVGSLs. We analyze the possible causes of the intermediate behavior of RanDim-FVGSLs. In specific, we assess the contribution of extended states related to the double resonant cavity and commensurate superlattice structure intrinsic to RanDim-FVGSLs.