Shot noise fluctuations in disordered graphene nanoribbons near the Dirac point

TL;DR

This paper investigates the statistical fluctuations of shot noise in disordered graphene nanoribbons, revealing how edge structure influences electron localization and noise behavior through analytical and numerical methods.

Contribution

It provides the first detailed comparison of shot noise distributions in zigzag and armchair graphene nanoribbons, highlighting the role of different electron localization mechanisms.

Findings

Shot noise statistics differ significantly between zigzag and armchair nanoribbons.

Edge states in zigzag nanoribbons are Anderson localized, while in armchair nanoribbons electrons are anomalously localized.

Numerical simulations confirm analytical predictions of shot noise behavior.

Abstract

Random fluctuations of the shot-noise power in disordered graphene nanoribbons are studied. In particular, we calculate the distribution of the shot noise of nanoribbons with zigzag and armchair edge terminations. We show that the shot noise statistics is different for each type of these two graphene structures, which is a consequence of presence of different electron localizations: while in zigzag nanoribbons electronic edge states are Anderson localized, in armchair nanoribbons edge states are absent, but electrons are anomalously localized. Our analytical results are verified by tight binding numerical simulations with random hopping elements, i.e., off diagonal disorder, which preserves the symmetry of the graphene sublattices.