2015/01/31 by Jochen Zahn · 7 citations
Mathematics · Physics and Astronomy · #Current (fluid) #Current density #Electric field #Electron #Field (mathematics) #High-Energy Particle Collisions Research #Linearization #Mathematics #Nonlinear system #Pair production #Physics #Quantum #Quantum Electrodynamics and Casimir Effect #Quantum and Classical Electrodynamics #Quantum electrodynamics #Quantum mechanics #hep-ph #hep-th
paper · pdf · doi:10.1088/1751-8113/48/47/475402
published in Journal of Physics A Mathematical and Theoretical 48(47), 475402 (Institute of Physics) · 15 pages, 4 figures; v3: Discussion more detailed, interpretation of the results modified, v4: Final version
openalex publication_date 2015/10/27 · arxiv created 2015/10/28 · arxiv updated 2015/10/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
In the framework of quantum electrodynamics (QED) in external potentials, we introduce a method to compute the time-dependence of the expectation value of the current density for time-dependent homogeneous external electric fields. We apply it to the so-called Sauter pulse. For late times, our results agree with the asymptotic value due to electron-positron pair production. We correct a general expression derived by Serber for the expectation value of the current, linearized in the external field, and compare with our results for the Sauter pulse. Based on the properties of the current density, we argue that the appearance of enhanced quasi-particle densities at intermediate times in slowly varying sub-critical potentials is generic. Also an alternative approach, which circumvents these difficulties, is sketched.