Phase-space analysis of the Schwinger effect in inhomogeneous electromagnetic fields

TL;DR

This paper investigates the Schwinger effect in complex electromagnetic fields using advanced numerical methods to analyze particle distributions, phase effects, and spin interactions in high-intensity, inhomogeneous pulses.

Contribution

It introduces a detailed numerical approach combining quantum kinetic theory with coarse-graining to study pair production in inhomogeneous fields, including spin and phase effects.

Findings

Numerical solutions reveal detailed momentum-space distributions.

Carrier-envelope phase influences pair production signatures.

Spin-field interactions are significant in the particle dynamics.

Abstract

Schwinger pair production in spatially and temporally inhomogeneous electric and magnetic fields is studied. The focus is on the particle phase-space distribution within a high-intensity few-cycle pulse. Accurate numerical solutions of a quantum kinetic theory (DHW formalism) are presented in momentum space and, with the aid of coarse-graining techniques, in a mixed spatial-momentum representation. Additionally, signatures of the carrier-envelope phase as well as spin-field interactions are discussed on the basis of a trajectory-based model taking into account instantaneous pair production and relativistic single-particle dynamics. Although our simple semi-classical single-particle model cannot describe every aspect of the particle production process (quantum interferences), essential features such as spin-field interactions are captured.