Conductance quantization and transport gap in disordered graphene nanoribbons

TL;DR

This paper investigates how edge and bulk disorder affect conductance in graphene nanoribbons, revealing that disorder suppresses conductance steps, induces transport gaps, and limits their use in ballistic applications.

Contribution

It provides a numerical analysis of disorder effects on conductance, highlighting the emergence of transport gaps and conductance suppression in disordered graphene nanoribbons.

Findings

Conductance steps are suppressed by edge roughness.

Transport gaps are inversely proportional to nanoribbon width.

On/off ratios grow exponentially with length.

Abstract

We study numerically the effects of edge and bulk disorder on the conductance of graphene nanoribbons. We compute the conductance suppression due to localization induced by edge scattering. We find that even for weak edge roughness, conductance steps are suppressed and transport gaps appear. These gaps are approximately inversely proportional to the nanoribbon width. On/off conductance ratios grow exponentially with the nanoribbon length. Our results impose severe limitations to the use of graphene in ballistic nanowires.