Vortex Structures and Momentum Sharing in Dynamic Sauter–Schwinger Process

Abstract

Vortex pattern formation in the electron–positron pair creation from a vacuum by a time-dependent electric field of linear polarization is analyzed. It is demonstrated that in such a scenario the momentum distributions of the created particles exhibit vortex–antivortex pairs. Their sensitivity to the laser field parameters, such as field frequency and intensity, is also studied. Specifically, it is shown that with increasing field frequency across a threshold, additional vortex–antivortex pairs appear. Their location in the momentum space is consistent with the general threshold behavior of the probability distributions of the created electrons (positrons). Namely, while for small field frequencies the particles tend to be created along the field polarization direction, for large enough frequencies, they are predominantly generated in the perpendicular direction. Such a change in the longitudinal and transverse momentum sharing of the created particles occurs across a threshold.