Dynamically assisted Sauter-Schwinger effect — non-perturbative versus perturbative aspects

• Published in: The journal of high energy physics Vol. 2017; no. 6; pp. 1 - 26
• Main Authors: Torgrimsson, G., Schneider, C., Oertel, J., Schützhold, R.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.06.2017; Springer Nature B.V; SpringerOpen
• Subjects: Amplitudes; Classical and Quantum Gravitation; Computer simulation; Electron-positron pairs; Elementary Particles; High energy physics; Mathematical models; Nonperturbative Effects; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Regular Article - Theoretical Physics; Relativity Theory; Solitons Monopoles and Instantons; String Theory; Time dependence; Nonperturbative Effects; Solitons Monopoles and Instantons
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP06(2017)043

A bstract The Sauter-Schwinger effect predicts the creation of electron-positron pairs out of the quantum vacuum by a strong and slowly varying electric field. This effect can be dynamically assisted by an additional weaker time-dependent field, which may drastically enhance the pair-creation probability. In previous studies, it has been found that the enhancement may crucially depend on the temporal shape of this weaker pulse, e.g., a Gaussian profile exp{−(ω t ) 2 } or a Sauter pulse 1 / cosh 2 (ω t ) behave quite differently. In order to understand this difference, we make a perturbative expansion in terms of the weaker field while treating the strong electric field non-perturbatively. For a large class of profiles including the Sauter pulse, already the sum of the zeroth-order and the first-order amplitudes of this perturbative expansion yields good agreement. For other cases, such as a Gaussian or sinusoidal profile, this is not true in general and higher orders can yield the dominant contribution — where the dominant order depends on the chosen parameters. Our findings are confirmed by numerical simulations and help us to sort previous results into a bigger picture.