Sauter-Schwinger effect for colliding laser pulses

TL;DR

This paper investigates electron-positron pair creation in colliding laser pulses using analytical and numerical methods, revealing exponential dependence similar to time-dependent fields and effects of spatial inhomogeneities.

Contribution

It introduces a generalized WKB approach to analyze pair creation in colliding laser fields, accounting for focusing effects and validating results with numerical simulations.

Findings

Pair creation rate exhibits exponential dependence similar to purely time-dependent fields.

Spatial inhomogeneities induce focusing or de-focusing effects on pair production.

Analytical results agree well with numerical Dirac-Heisenberg-Wigner simulations.

Abstract

Via a combination of analytical and numerical methods, we study electron-positron pair creation by the electromagnetic field ${\bf A}(t,{\bf r})=[f(ct-x)+f(ct+x)]{\bf e}_y$ of two colliding laser pulses. Employing a generalized WKB approach, we find that the pair creation rate along the symmetry plane $x=0$ (where one would expect the maximum contribution) displays the same exponential dependence as for a purely time-dependent electric field ${\bf A}(t)=2f(ct){\bf e}_y$. The pre-factor in front of this exponential does also contain corrections due to focusing or de-focusing effects induced by the spatially inhomogeneous magnetic field. We compare our analytical results to numerical simulations using the Dirac-Heisenberg-Wigner method and find good agreement.