Optimizing the pulse shape for Schwinger pair production

Abstract

Recent studies of the dynamically assisted Schwinger effect have shown that particle production is significantly enhanced by a proper choice of the electric field. We demonstrate that optimal control theory provides a systematic means of modifying the pulse shape in order to maximize the particle yield. We employ the quantum kinetic framework and derive the relevant optimal control equations. By means of simple examples we discuss several important issues of the optimization procedure such as constraints, initial conditions or scaling. By relating our findings to established results we demonstrate that the particle yield is systematically maximized by this procedure.Comment: 11 pages, 6 figures. Revised version: Discussion extended (introduction, section III.C, conclusion) and references added, PRD Versio

Schwinger mechanism revisited

“…Optimization of the field profile to gain the maximum particle yield has been investigated in refs. [139][140][141]. …”

Assisted dynamical Schwinger effect: pair production in a pulsed bifrequent field

“…Here, the optimization theory [19,22] is certainly very useful to search for parameters suitable for maximum amplification. Upon restricting to a narrow patch in the parameter space one can constrain the ansatz for the superposition of a strong and a weak pulse, each with sub-cycles, to…”

“…The enhancement of Schwinger type pair production by an assisting field has been considered already in references [7,[16][17][18][19][20][21][22][23][24], e.g., for (i) a constant field plus some pulse with or without subcycle structures [20];…”

Low-dimensional approach to pair production in an oscillating electric field: Application to bandgap graphene layers

“…Many of them rely on the theoretical framework of QED in unstable vacuum [41]. In the case of a spatially homogeneous but time dependent electric field E E E(t) = (0, E(t), 0), 4 such a framework allows us to undertake the problem either through the S-matrix formalism [35, 46-50, 63, 69] or from the transport theory point of view [19,[53][54][55][56][57][58][59][60]66]. Both formulations are equivalent and complement each other.…”