Correlated two-photon emission by transitions of Dirac-Volkov states in intense laser fields: QED predictions

TL;DR

This paper predicts and analyzes the correlated emission of photon pairs from electrons in intense laser fields, revealing significant differences from traditional scattering models by employing nonperturbative QED calculations with Volkov states.

Contribution

It introduces a nonperturbative QED approach using Volkov states to calculate correlated two-photon emission in intense laser fields, highlighting differences from standard models.

Findings

Calculated differential rate and concurrence for photon polarization correlations.

Demonstrated significant differences between nonperturbative and perturbative results.

Provided gauge-invariant measures of photon entanglement in laser-electron interactions.

Abstract

In an intense laser field, an electron may decay by emitting a pair of photons. The two photons emitted during the process, which can be interpreted as a laser-dressed double Compton scattering, remain entangled in a quantifiable way: namely, the so-called concurrence of the photon polarizations gives a gauge-invariant measure of the correlation of the hard gamma rays. We calculate the differential rate and concurrence for a backscattering setup of the electron and photon beam, employing Volkov states and propagators for the electron lines, thus accounting nonperturbatively for the electron-laser interaction. The nonperturbative results are shown to differ significantly compared to those obtained from the usual double Compton scattering.