J. Braß | Searcharxiv

arXiv2025

Relative-phase dependence of dynamically assisted electron-positron pair creation in the superposition of strong oscillating electric-field pulses

Production of electron-positron pairs in the superposition of oscillating electric-field pulses with largely different frequencies is studied, focussing on the impact of relative phases between the pulses. Various field configurations are considered: superpositions of either two or three pulses of equal duration as well as combinations of a long low-frequency and a short high-frequency pulse. We show that the relative phase of superimposed high-frequency modes can exert a sizeable effect on the total numbers of produced pairs, enhancing them by about 10-30% for the considered field parameters.

physics.atom-ph↗

arXiv2019

Two-color phase-of-the-phase spectroscopy applied to nonperturbative electron-positron pair production in strong oscillating electric fields

Production of electron-positron pairs from vacuum in strong bichromatic electric fields, oscillating in time with a fundamental frequency and its second harmonic, is studied. Strong-field processes occuring in such field configurations are generally known to be sensitive to the relative phase between the field modes. Phase-of-the-phase spectroscopy has recently been introduced in the context of strong-field photoionization as a systematic means to analyze these coherence effects. We apply this method to field-induced pair production by calculating the phase dependence of the momentum-resolved particle yields. We show that asymmetric checkerboard patterns arise in the phase-of-the-phase spectra, similarly to those found in strong-field photoionization. The physical origin of these characteristic structures, which differ between the created electron and positron, are discussed.

physics.atom-ph↗