Electron-positron pair production in frequency modulated laser fields

TL;DR

This paper investigates how frequency modulation in laser fields affects electron-positron pair production, revealing interference patterns and ways to significantly enhance pair density.

Contribution

It introduces a quantum kinetic approach to analyze the impact of frequency modulation on pair production, highlighting interference effects and potential for increasing pair yields.

Findings

Interference patterns in momentum spectra due to frequency modulation.

Pair number density can be enhanced by over two orders of magnitude.

Sensitivity of pair density to modulation parameters.

Abstract

The momentum spectrum and the number density of created electron-positron pairs in a frequency modulated laser field are investigated using quantum kinetic equation. It is found that the momentum spectrum presents obvious interference pattern. This is an imprint of the frequency modulated field on the momentum spectrum, because the momentum peaks correspond to the pair production process by absorbing different frequency component photons. Moreover, the interference effect can also be understood qualitatively by analyzing turning point structures. The study of the pair number density shows that the number density is very sensitive to modulation parameters and can be enhanced by over two orders of magnitude for certain modulation parameters, which may provide a new way to increase the number of created electron-positron pairs in future experiments.