Capacitor discharge and vacuum resistance in massless QED2

A charged parallel plate capacitor will create particle-antiparticle pairs by the Schwinger process and discharge over time. We consider the full quantum discharge process in 1 + 1 dimensions including backreaction, when the electric field interacts with massless charged fermions. We recover oscillatory features in the electric field observed in a semiclassical analysis and find that the amplitude of the oscillations falls off as t(-1/2) and that stronger coupling implies slower decay. Remarkably, Ohm's law applies to the vacuum and we evaluate the quantum electrical conductivity of the vacuum to be 2e/root pi, where e is the fermionic charge. Similarities and differences with black hole evaporation are mentioned.