Momentum signatures for Schwinger pair production in short laser pulses with a sub-cycle structure

TL;DR

This paper studies how short laser pulses with sub-cycle structures influence Schwinger pair production, revealing that the momentum spectrum of created pairs is highly sensitive to pulse parameters, which can aid experimental detection and pulse design.

Contribution

It demonstrates the sensitivity of electron-positron pair momentum spectra to sub-cycle laser pulse parameters using a non-equilibrium quantum kinetic approach, revealing new signatures.

Findings

Momentum spectrum depends on laser frequency, pulse length, and phase.

Identifies distinctive signatures in pair production spectra.

Potential for optimizing experimental detection of Schwinger pairs.

Abstract

We investigate electron-positron pair production from vacuum for short laser pulses with sub-cycle structure, in the nonperturbative regime (Schwinger pair production). We use the non-equilibrium quantum kinetic approach, and show that the momentum spectrum of the created electron-positron pairs is extremely sensitive to the sub-cycle dynamics -- depending on the laser frequency $\omega$, the pulse length $\tau$, and the carrier phase $\phi$ -- and shows several distinctive new signatures. This observation could help not only in the design of laser pulses to optimize the experimental signature of Schwinger pair production, but also ultimately lead to new probes of light pulses at extremely short time scales.