Semiclassical pair production rate for rotating electric fields

TL;DR

This paper develops a semiclassical approach to analyze Schwinger pair production in pulsed rotating electric fields, revealing spin-dependent effects and interference phenomena in the pair creation process.

Contribution

It introduces a WKB-like approximation for the Dirac equation in rotating fields, showing spin asymmetries and providing an analytical momentum spectrum for constant rotating fields.

Findings

Pair production rates differ for spinor and scalar QED.

Spin distribution of produced pairs is generally not 1:1.

Interference effects influence the total particle number.

Abstract

We semiclassically investigate Schwinger pair production for pulsed rotating electric fields depending on time. To do so we solve the Dirac equation for two-component fields in a WKB-like approximation. The result shows that for two-component fields the spin distribution of produced pairs is generally not $1:1$. As a result the pair creation rates of spinor and scalar quantum electro dynamics (QED) are different even for one pair of turning points. For rotating electric fields the pair creation rate is dominated by particles with a specific spin depending on the sense of rotation for a certain range of pulse lengths and frequencies. We present an analytical solution for the momentum spectrum of the constant rotating field. We find interference effects not only in the momentum spectrum but also in the total particle number of rotating electric fields.