# Modulation effect in multiphoton pair production

## TL;DR

This paper studies how amplitude modulation in oscillating fields enhances electron-positron pair production, lowering frequency thresholds and significantly increasing production rates, with potential applications in quantum field experiments.

## Contribution

It demonstrates that amplitude modulation can substantially boost pair production rates and lower frequency thresholds, revealing new control mechanisms in quantum kinetic processes.

## Key findings

- Pair production rate can be enhanced by several orders with modulation.
- Frequency threshold can be lowered by pulse train modulation.
- Number density scales as N^2 with pulse number, following a power law with index 1.6.

## Abstract

We investigate the electron-positron pair production process in an oscillating field with modulated amplitude in quantum kinetic formalism. By comparing the number density in field with and without modulation, we find that the pair production rate can be enhanced by several orders when the photon energy just reach the threshold with the help of shifted frequency due to modulation. We also detect the same effect in a pulse train with subcycle structure. We demonstrate that the frequency threshold can be lowered by frequency of pulse-train due to modulation effect. We also find that the momentum distribution for $N$-pulse train can reach $N^2$ times the single pulse at the maximum value and the number density as a function of pulse number follows the power laws with index $1.6$ when the modulation effect is maximized.