Measuring the Boiling Point of the Vacuum of Quantum Electrodynamics

TL;DR

This paper proposes an experimental method to measure the Schwinger critical field, the threshold for vacuum instability in quantum electrodynamics, using high-energy photon interactions in intense laser fields.

Contribution

It introduces a novel approach to determine the vacuum boiling point of QED by observing pair production from bremsstrahlung photons in high-intensity lasers.

Findings

Proposes measuring pair production rates to determine the Schwinger critical field.

Links vacuum instability to observable photon-induced pair creation.

Suggests a feasible experimental setup for testing QED predictions.

Abstract

It is a long-standing non-trivial 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 $|\mathbf E|$ of order the Schwinger critical field, ${\rm E}_c=m_e^2/e\simeq 1.3\times 10^{18}\ {\rm V/m}$, 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.