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arXiv · 1302.0860

Incompatibility of the tunneling limit with laser fields

H. R. Reiss
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Abstract

The Schwinger limit refers to longitudinal electric fields that are sufficiently strong to "polarize the vacuum" into electron-positron pairs by a tunneling mechanism. Laser fields are transverse electromagnetic fields for which the Schwinger limit has no relevance. Longitudinal and transverse fields are fundamentally different because of the different values of the F^{{\mu}{\nu}}F_{{\mu}{\nu}} Lorentz invariant that characterizes the fields. One aspect of this difference is the zero-frequency limit, that exists for longitudinal fields, but is ill-defined for transverse fields. The goal of approaching the Schwinger limit with sufficiently strong lasers is thus not a possibility. Tunneling transition rates are characterized by an exponential behavior of the form exp(-C/E), where E is the magnitude of the applied electric field and C is a system-dependent constant. Searches for such behavior within a Coulomb-gauge treatment of laser-induced processes are shown to fail.

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H. R. Reiss. 2013-02-01. Incompatibility of the tunneling limit with laser fields. https://arxiv.org/abs/1302.0860

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