AC transport in graphene-based Fabry-Perot devices

TL;DR

This paper provides a theoretical analysis of how time-dependent fields influence electronic transport and interference patterns in graphene nanoribbon devices, emphasizing the impact of edge geometry and noise characteristics.

Contribution

It introduces a detailed theoretical model showing how ac gating affects Fabry-Pérot interference in graphene nanoribbons with different edge types, highlighting geometric effects.

Findings

Armchair edges allow controllable regular interference patterns.

Zigzag edges produce complex interference due to electronic structure.

Conditions identified for minimizing current fluctuations.

Abstract

We report on a theoretical study of the effects of time-dependent fields on electronic transport through graphene nanoribbon devices. The Fabry-P\'{e}rot interference pattern is modified by an ac gating in a way that depends strongly on the shape of the graphene edges. While for armchair edges the patterns are found to be regular and can be controlled very efficiently by tuning the ac field, samples with zigzag edges exhibit a much more complex interference pattern due to their peculiar electronic structure. These studies highlight the main role played by geometric details of graphene nanoribbons within the coherent transport regime. We also extend our analysis to noise power response, identifying under which conditions it is possible to minimize the current fluctuations as well as exploring scaling properties of noise with length and width of the systems.