Spin effect in vacuum pair production under two-color rotating electric fields

TL;DR

This paper explores how spin influences vacuum pair production in two-color rotating electric fields, revealing that spin effects are significant and highly sensitive to field asymmetry, chirp, and time delay, with potential for large particle number density increases.

Contribution

It demonstrates the spin dependence of vacuum pair production under complex electric field configurations using the DHW formalism, highlighting the impact of field parameters on spin asymmetry.

Findings

Spin effects are significant even in pure electric fields.

Field asymmetry and chirp can reverse spin asymmetry.

Particle number density can increase by over six orders of magnitude.

Abstract

We investigated the spin effect on the vacuum pair production by Dirac-Heisenberg-Wigner (DHW) formalism under two-color counter-rotating electric fields. We primarily studied the combined effects of the field asymmetry, time delay, and frequency chirp on the particle momentum spectrum with and without considering the spin effect. We have observed that the vacuum pair production process demonstrates spin dependence even in a pure electric field and is sensitive to variations in the field parameters. The results indicate that the spin-dependent momentum spectrum exhibited distinct outcomes for various asymmetric fields with different chirp values and time delay. For an extended asymmetric field with large chirp and time delay, the particle number density can be increased by more than six orders of magnitude. The spin-up and spin-down particles are approximately comparable for a symmetric field with a small-frequency chirp and are dominated by the spin-up particles for a larger chirp. However, in the case of an asymmetric field, the increase in field asymmetry and the chirp parameter lead to a reversal of the spin asymmetry degree. For a shortened asymmetric electric field with a large-frequency chirp, the number of spin-up particles increases, leading to a spin asymmetry degree of $98.62\%$. Conversely, in an extended asymmetric field, the number of spin-down particles increases significantly, which corresponds to a spin asymmetry degree of $99.94\%$.