Sauter-Schwinger effect for colliding laser pulses

Abstract

Via a combination of analytical and numerical methods, we study electron-positron pair creation by the electromagnetic field $\mathbf{A}(t,\mathbf{r})=[f(ct-x)+f(ct+x)]{\mathbf{e}}_y$ 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 $\mathbf{A}(t)=2f(ct){\mathbf{e}}_y$. 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.

Comments: Article: 7 pages, 1 figure; Appendix: 9 pages, 5 figures; v3: added discussions on numerics and convergences as well as curvature contributions in the appendix, added new references