Photon-photon interaction in structured QED vacuum

TL;DR

This paper explores how structured strong laser fields induce nonlinear optical effects in the quantum electrodynamical vacuum, leading to enhanced photon-photon interactions through coherent four-wave mixing and Bragg interference.

Contribution

It introduces a novel analysis of photon-photon scattering in structured QED vacuum, emphasizing the role of phase-matching and Bragg interference in enhancing nonlinear effects.

Findings

Enhanced vacuum polarization and magnetization in structured fields

Identification of phase-matching conditions for photon scattering

Demonstration of coherent four-wave mixing with Bragg interference

Abstract

In spatially structured strong laser fields, quantum electrodynamical vacuum behaves like a nonlinear Kerr medium with modulated third-order susceptibility where new coherent nonlinear effects arise due to modulation. We consider the enhancement of vacuum polarization and magnetization via coherent spatial vacuum effects in the photon-photon interaction process during scattering of a probe laser beam on parallel focused laser beams. Both processes of elastic and inelastic four wave-mixing in structured QED vacuum accompanied with Bragg interference are investigated. The phase-matching conditions and coherent effects in the presence of Bragg grating are analyzed for photon-photon scattering.