Resonant Features in Bilayer Nanoribbons in a Single Mode Regime with a Short Range Defect

Abstract

We have studied resonant features in bilayer nanoribbon in a single mode regime with a short range defect. We have found the effect of edge disorder on the transport properties of a graphene nanoribbons and bilayer graphene nano-ribbons. We have developed an analytical approach that provides the exact results for the transmission coefficients of graphene nanoribbons. We have considered the case of bilayer graphene nanoribbons with zigzag and armchair edges. We have found that for the case of zigzag edge bilayer nanoribbon remain practically insensitive to the disorder situated close to the edges. This behavior is not related to the chiral edge state residing at the zigzg boundary, as this behavior persist into the few mode regime as well. It is related to the effective boundary condition at the zigzag edge which does not couple valleys, thus hindering the intervally scattering due to the edge disorder. The armchair edge mixes the valleys and it is found that the conductance of a graphene nanoribbons and a bilayer graphene nanoribbons is strongly affected by a small defect concentration. We have calculated the conductance in bilayer graphene nanoribbons with many defects on the basis of tight binding recursive Green’s function technique.