Conductance of disordered graphene superlattice

TL;DR

This paper investigates how short-range structural correlations in disordered graphene superlattices affect electron conductance, revealing conditions under which conductance persists or vanishes as system size increases.

Contribution

It provides new insights into the conductance behavior of disordered graphene superlattices with correlated disorder, including conditions for nonzero conductance in large systems.

Findings

Perpendicular quasiparticles transmit efficiently through disordered barriers.

Conductance vanishes in large systems for most structures.

Certain structures maintain nonzero conductance in the thermodynamic limit.

Abstract

We study the conductance of disordered graphene superlattices with short-range structural correlations. The system consists of electron- and hole-doped graphenes of various thicknesses, which fluctuate randomly around their mean value. The effect of the randomness on the probability of transmission through the system of various sizes is studied. We show that in a disordered superlattice the quasiparticle that approaches the barrier interface almost perpendicularly transmits through the system. The conductivity of the finite-size system is computed and shown that the conductance vanishes when the sample size becomes very large, whereas for some specific structures the conductance tends to a nonzero value in the thermodynamics limit.