Shot Noise Suppression and Hopping Conduction in Graphene Nanoribbons

TL;DR

This study explores shot noise suppression and hopping conduction in graphene nanoribbons at low temperatures, revealing inelastic hopping behavior and strong shot noise suppression linked to localization effects.

Contribution

It demonstrates the relationship between shot noise suppression and variable range hopping in graphene nanoribbons, highlighting inelastic hopping in the crossover regime.

Findings

Transport follows variable range hopping laws

Strong shot noise suppression with low Fano factors

Localization length is less than ribbon width

Abstract

We have investigated shot noise and conduction of graphene field effect nanoribbon devices at low temperature. By analyzing the exponential $I-V$ characteristics of our devices in the transport gap region, we found out that transport follows variable range hopping laws at intermediate bias voltages $1 < V_{bias} < 12$ mV. In parallel, we observe a strong shot noise suppression leading to very low Fano factors. The strong suppression of shot noise is consistent with inelastic hopping, in crossover from one- to two-dimensional regime, indicating that the localization length $l_{loc} < W$ in our nanoribbons.