# Signatures of the Schwinger mechanism assisted by a fast-oscillating electric field

## TL;DR

This paper investigates the nonperturbative Schwinger mechanism enhanced by a high-frequency electric field, deriving analytical expressions for pair production rates and proposing an experimental setup to observe the effect.

## Contribution

It provides the first analytical formula for the density rate of electron-positron pairs in a dynamically-assisted Schwinger process, bridging tunneling and multi-photon regimes.

## Key findings

- Derived asymptotic expressions for pair production distribution.
- Established a nonperturbative dependence of particle density on electric fields.
- Proposed an experimental setup to observe the effect.

## Abstract

The spontaneous production of electron-positron pairs from the vacuum--in a field configuration composed of a high-frequency electric mode of weak intensity and a strong constant electric field--is investigated. Asymptotic expressions for the single-particle distribution function ruling this nonperturbative process are established by considering the low-density approximation in the Boltzmann-Vlasov equation. An analytical formula for the density rate of yielded particles is established which is shown to manifest a nonperturbative dependence on both the strong and weak electric fields and to interpolate between the tunneling and multi-photon regimes. It is shown that--under appropriate circumstances--the produced plasma of electrons and positrons might reach densities for which their recombinations into high-energy photons occurs copiously. On the basis of this feature, an experimental setup for observing the dynamically-assisted Schwinger effect is put forward.