Abstract
We study electron-positron pair creation by a strong and constant electric field superimposed with a weaker transversal plane wave which is incident perpendicularly (or under some angle). Comparing the fully non-perturbative approach based on the world-line instanton method with a perturbative expansion into powers of the strength of the weaker plane wave, we find good agreement - provided that the latter is carried out to sufficiently high orders. As usual for the dynamically assisted Sauter-Schwinger effect, the additional plane wave induces an exponential enhancement of the pair-creation probability if the combined Keldysh parameter exceeds a certain threshold.
Highlights
As one of the most striking consequences of quantum field theory, extreme external conditions can tear apart quantum vacuum fluctuations and thereby create real particles
We study electron-positron pair creation by a strong and constant electric field superimposed with a weaker transversal plane wave which is incident perpendicularly
As an example for the dynamically assisted SauterSchwinger effect, we studied electron-positron pair creation due to a strong and constant electric field E superimposed by a weaker transversal plane wave with a frequency Ω and field strength εE
Summary
As one of the most striking consequences of quantum field theory, extreme external conditions can tear apart quantum vacuum fluctuations and thereby create real particles. For longitudinal parallel waves, Ezðt þ zÞ, the pair creation probability is given by the locally constant field approximation [21,22,23], which implies that the enhancement is comparably small Both results can be understood by considering a Lorentz boost along the direction of the strong field which leaves the strong field invariant but reduces the frequency of the plane wave, see [24]. Eðt; xÞ 1⁄4 Eez þ εE cosðΩ1⁄2t − xÞez; ð2Þ corresponding to the vector potential (in temporal gauge) Azðt; xÞ 1⁄4 Et þ εE sinðΩ1⁄2t − xÞ=Ω This scenario has several advantages: since such a transversal wave cannot create electron-positron pairs on its own (due to a similar Lorentz boost argument as above), pair creation can only occur in cooperation with the strong field E, which retains the nonperturbative character of this effect. Note that this profile (2) was already considered in [25] using first-order perturbation theory in ε, whereas we are going to consider higher orders as well as a fully nonperturbative approach
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
