2023/08/22 by Hidetoshi Taya, C. N. Ironside, Taya, Hidetoshi +1
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Quantum and electron transport phenomena #Physics of Superconductivity and Magnetism
paper · pdf · doi:10.48550/arxiv.2308.11248
We study the electric permittivity of the QED vacuum in the presence of a strong constant electric field, motivated by the analogy between the dynamically-assisted Schwinger effect in strong-field QED and the Franz-Keldysh effect in semiconductor physics. We develop a linear-response theory based on the non-equilibrium in-in formalism and the Furry-picture perturbation theory, with which and also utilizing the Kramers-Krönig relation, we calculate the electric permittivity without assuming weak fields and low-frequency probes. We discover that the electric permittivity exhibits characteristic oscillating dependence on the probe frequency, which directly reflects the change of the QED-vacuum structure by the strong field. We also establish a quantitative correspondence between the electric permittivity and the number of electron-positron pairs produced by the dynamically-assisted Schwinger effect.