Ballistic transport through irradiated graphene

TL;DR

This paper investigates how circularly polarized light influences charge transport in graphene ribbons, revealing conductance dips at photon resonances and linking residual conductance to evanescent states and Floquet spectrum features.

Contribution

It provides a theoretical analysis of photon-induced conductance features in irradiated graphene, highlighting the role of dynamical gaps and evanescent states in transport properties.

Findings

Broad conductance dips at photon resonances

Residual conductance linked to evanescent states

Dynamical gaps in Floquet spectrum affect transport

Abstract

The coherent charge transport through an illuminated graphene ribbon is studied as function of electronic doping, frequency and strength of the electromagnetic driving, for monochromatic circularly polarized light. We focus on the DC current carried by 2D bulk carriers which is dominant (over edge transport) for short and wide enough samples. Broad dips in conductance are predicted for one-photon and multi-photon resonances between the valence and conductance bands. The residual conductance can be associated with evanescent states and related to dynamical gaps in the Floquet quasi-energy spectrum.