Radiation from electrons in graphene in strong electric field

TL;DR

This paper investigates photon emission from electrons in graphene under strong electric fields, revealing the interplay between electron-hole pair creation and spontaneous emission, and suggesting possible observation of the Schwinger effect.

Contribution

It provides a theoretical framework for photon emission in graphene under strong fields, including exact solutions and emission probabilities, highlighting the potential to observe the Schwinger effect.

Findings

Photon emission probabilities depend on angle and frequency.

Electron-hole pair creation influences emission patterns.

Possible experimental observation of the Schwinger effect in graphene.

Abstract

We study the interaction of electrons in graphene with the quantized electromagnetic field in the presence of an applied uniform electric field using the Dirac model of graphene. Electronic states are represented by exact solutions of the Dirac equation in the electric background, and amplitudes of first-order Feynman diagrams describing the interaction with the photon field are calculated for massive Dirac particles in both valleys. Photon emission probabilities from a single electron and from a many-electron system at the charge neutrality point are derived, including the angular and frequency dependence, and several limiting cases are analyzed. The pattern of photon emission at the Dirac point in a strong field is determined by an interplay between the nonperturbative creation of electron-hole pairs and spontaneous emission, allowing for the possibility of observing the Schwinger effect in measurements of the radiation emitted by pristine graphene under DC voltage.