Pulse shape dependence in the dynamically assisted SauterSchwinger effect
Abstract
While the SauterSchwinger effect describes nonperturbative electronpositron pair creation from vacuum by a strong and slowly varying electric field E_{strong} via tunneling, the dynamically assisted SauterSchwinger effect corresponds to a strong (exponential) enhancement of the paircreation probability by an additional weak and fast electric or electromagnetic pulse E_{weak}. Using the WKB and worldline instanton method, we find that this enhancement mechanism strongly depends on the shape of the fast pulse. For the Sauter profile 1 /cosh^{2}(ω t ) considered previously, the threshold frequency ω_{crit} (where the enhancement mechanism sets in) is basically independent of the magnitude E_{weak} of the weak pulse—whereas for a Gaussian pulse exp (ω^{2}t^{2}), an oscillating profile cos (ω t ) or a standing wave cos (ω t )cos (k x ) , the value of ω_{crit} does depend (logarithmically) on E_{weak}/E_{strong}.
 Publication:

Physical Review D
 Pub Date:
 October 2015
 DOI:
 10.1103/PhysRevD.92.085009
 arXiv:
 arXiv:1505.05685
 Bibcode:
 2015PhRvD..92h5009L
 Keywords:

 12.20.m;
 11.15.Tk;
 Quantum electrodynamics;
 Other nonperturbative techniques;
 High Energy Physics  Theory
 EPrint:
 13 pages REVTeX, 9 (sub)figures