# Measuring the boiling point of the vacuum of quantum electrodynamics

Hartin, Anthony (University College London, Gower Street, London WC1E 6BT, United Kingdom) ; Ringwald, Andreas (DESY, Notkestrasse 85, 22607 Hamburg, Germany) ; Tapia, Natalia (Departamento de Fisica, Universidad de Santiago de Chile, Casilla 307, 9170124 Santiago, Chile)

12 February 2019

Abstract: It is a long-standing nontrivial prediction of quantum electrodynamics that its vacuum is unstable in the background of a static, spatially uniform electric field and, in principle, sparks with spontaneous emission of electron-positron pairs. However, an experimental verification of this prediction seems out of reach because a sizeable rate for spontaneous pair production requires an extraordinarily strong electric field strength $|E|$ of order the Schwinger critical field, ${E}_{c}={m}_{e}^{2}/e\simeq 1.3×{10}^{18}\text{}\text{}V/m$, where ${m}_{e}$ is the electron mass and $e$ is its charge. Here, we show that the measurement of the rate of pair production due to the decays of high-energy bremsstrahlung photons in a high-intensity laser field allows for the experimental determination of the Schwinger critical field and, thus, the boiling point of the vacuum of quantum electrodynamics.

Published in: Physical Review D 99 (2019)