Berlin 2014 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 35: Quantum effects: QED I
Q 35.2: Talk
Thursday, March 20, 2014, 11:00–11:15, DO26 208
Pulse shape dependence in the dynamically assisted Sauter-Schwinger effect — Joachim Sicking, •Nikodem Szpak, and Ralf Schützhold — Fakultät für Physik, Universität Duisburg-Essen
The Sauter-Schwinger effect describes the non-perturbative electron-positron pair creation from the vacuum by a strong and slowly varying electric field Estrong via tunnelling. Due to the smallness of the associated probabilities for realistic electric fields, this fundamental prediction of quantum field theory has not been observed yet. The dynamically assisted Sauter-Schwinger effect corresponds to a strong (exponential) enhancement of the pair creation probability by an additional weak and fast electric or electromagnetic pulse. We find that this enhancement mechanism depends strongly on the shape of the fast pulse. For the Sauter profile 1/cosh2(ω t) considered previously, the threshold frequency ωcrit (where the enhancement mechanism sets in) is basically independent of the magnitude Eweak of the weak pulse – whereas for a Gaussian pulse exp(−ω2t2) or a sinusoidal profile sin(ω t), the value of ωcrit does depend (logarithmically) on Eweak/Estrong.