Detectable Optical Signatures of QED Vacuum Nonlinearities Using High-Intensity Laser Fields

Leonhard Klar

doi:10.3390/particles3010018

Abstract

Up to date, quantum electrodynamics (QED) is the most precisely tested quantum field theory. Nevertheless, particularly in the high-intensity regime it predicts various phenomena that so far have not directly been accessible in all-optical experiments, such as photon-photon scattering phenomena induced by quantum vacuum fluctuations. Here, we focus on all-optical signatures of quantum vacuum effects accessible in the high-intensity regime of electromagnetic fields. We present an experimental setup giving rise to signal photons distinguishable from the background. This configuration is based on two optical pulsed petawatt lasers: one generates a narrow but high-intensity scattering center to be probed by the other one. We calculate the differential number of signal photons attainable with this field configuration analytically and compare it with the background of the driving laser beams.

Highlights

After Dirac predicted the positron and introduced his idea of the Dirac-Sea [1,2,3], Sauter used his theory to describe the creation of an electron-positron pair in presence of a strong electromagnetic field [4]
We analyze the setup introduced in the previous section, calculate the differential number of signal photons analytically and discuss the advantages
Let us compute the differential number of signal photons per shot d3N analytically

Summary

Introduction

After Dirac predicted the positron and introduced his idea of the Dirac-Sea [1,2,3], Sauter used his theory to describe the creation of an electron-positron pair in presence of a strong electromagnetic field [4]. In the 1930s, Heisenberg and Euler formulated a Lagrangian—the famous Heisenberg–Euler–Lagrangian LHE—that averages over the virtual electron-positron fluctuations. The latter predicts nonlinear self-interaction of electromagnetic fields in the quantum vacuum, facilitating photon-photon-scattering phenomena [5,6,7]. Due to the large advances in laser technology during recent decades, it might become possible to find signatures of quantum vacuum nonlinearities in experiments with strong laser fields in the near future. Various phenomenona of quantum vacuum nonlinearity, e.g., photon-photon scattering, vacuum birefringence, quantum reflection, photon splitting, and more, appear to be detectable with state-of-the-art lasers [8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32]

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Results

Conclusion