Suppressed conductance in a metallic graphene nano-junction

TL;DR

This paper investigates the conductance suppression in metallic graphene nano-junctions, revealing antiresonance effects linked to edge states, which are robust against impurities and tunable by electric fields.

Contribution

It demonstrates the origin of conductance suppression in graphene junctions as antiresonance from edge states and shows its robustness and tunability.

Findings

Conductance suppression near the Dirac point due to antiresonance.

Robustness of conductance valley against impurities and vacancies.

Electric field tuning of the conductance valley center.

Abstract

The linear conductance spectrum of a metallic graphene junction formed by interconnecting two gapless graphene nanoribbons is calculated. A strong conductance suppression appears in the vicinity of the Dirac point. We found that such a conductance suppression arises from the antiresonance effect associated with the edge state localized at the zigzag-edged shoulder of the junction. The conductance valley due to the antiresonance is rather robust in the presence of the impurity and vacancy scattering. And the center of the conductance valley can be readily tuned by an electric field exerted on the wider nanoribbon.