Signature of Schwinger's pair creation rate via radiation generated in graphene by strong electric current

TL;DR

This paper explores how strong electric currents in graphene induce Schwinger pair creation, leading to distinctive radiation signatures and nonlinear electrical behavior, including a second Ohmic regime caused by radiation friction.

Contribution

It provides a theoretical calculation of the radiation spectrum and analyzes the angular and polarization dependence of emitted photons in graphene under strong electric fields.

Findings

Radiation spectrum depends on electric field strength and current.

Distinctive angular and polarization patterns of emitted photons.

High currents induce a second Ohmic regime via radiation friction.

Abstract

Electron - hole pairs are copuously created by an applied electric field near the Dirac point in graphene or similar 2D electronic systems. It was shown recently that for sufficiently large electric fields and ballistic times the I-V characteristics become strongly nonlinear due to Schwinger's pair creation. Since there is no energy gap the radiation from the pairs' annihilation is enhanced. The spectrum of radiation is calculated. The angular and polarization dependence of the emitted photons with respect to the graphene sheet is quite distinctive. For very large currents the recombination rate becomes so large that it leads to the second Ohmic regime due to radiation friction.