2013/02/01 by Howard Reiss, Reiss, H. R.
Physics and Astronomy · #Atomic and Molecular Physics #FOS: Physical sciences #Laser-Matter Interactions and Applications #Optics (physics.optics) #Quantum Mechanics and Applications #Quantum Physics (quant-ph)
paper · pdf · doi:10.48550/arxiv.1302.0860
openalex publication_date 2013/02/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
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 FμνFμν 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.