Electromagnetic field induced suppression of transport through $n$-$p$ junctions in graphene

TL;DR

This paper demonstrates that electromagnetic radiation can induce a dynamic gap in graphene's spectrum, suppressing quasi-particle transport through $n$-$p$ junctions, enabling control over graphene-based electronic devices.

Contribution

It introduces a mechanism where electromagnetic fields create a non-equilibrium gap in graphene, significantly affecting transport properties and offering a new way to control graphene-based devices.

Findings

Electromagnetic field induces a dynamic gap in graphene spectrum.

The dynamic gap suppresses quasi-particle transmission.

Transport control is achievable by tuning radiation intensity and frequency.

Abstract

We study quasi-particle transmission through an $n $-$p$ junction in a graphene irradiated by an electromagnetic field (EF). In the absence of EF the electronic spectrum of undoped graphene is gapless, and one may expect the perfect transmission of quasi-particles flowing perpendicular to the junction. We demonstrate that the resonant interaction of propagating quasi-particles with the component of EF parallel to the junction induces a \textit{non-equilibrium dynamic gap} $(2\Delta_R)$ between electron and hole bands in the quasi-particle spectrum of graphene. In this case the strongly suppressed quasi-particle transmission is only possible due to interband tunnelling. The effect may be used for controlling transport properties of diverse structures in graphene, like, e.g., $n$-$p$-$n$ transistors, single electron transistors, quantum dots, etc., by variation of the intensity $S$ and frequency $\omega$ of the external radiation.