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

• Main Authors: G. Torgrimsson, C. Schneider, J. Oertel, R. Schützhold
• Format: Article
• Language: English
• Published: SpringerOpen 2017-06-01
• Series: Journal of High Energy Physics
• Subjects: Nonperturbative Effects; Solitons Monopoles and Instantons
• Online Access: http://link.springer.com/article/10.1007/JHEP06(2017)043

Abstract 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{−(ωt)2} or a Sauter pulse 1/ cosh2(ωt) 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.