Spatially Assisted Schwinger Mechanism and Magnetic Catalysis

Abstract

Using the worldline formalism we compute an effective action for fermions under a temporally modulated electric field and a spatially modulated magnetic field. It is known that the former leads to an enhanced Schwinger Mechanism, while we find that the latter can also result in enhanced particle production and even cause a reorganization of the vacuum to acquire a larger dynamical mass in equilibrium which spatially assists the Magnetic Catalysis.Comment: This is an erratum applied version to PRL117, 081603 (2016). We found a sign mistake and wrote an erratum with a conclusion that the central results are not changed once spatially decreasing magnetic fields are replaced with increasing ones. The Gaussian approximation leading to a wrong answer has also been improved to a systematic perturbative evaluatio