Plasma simulations using real-time lattice scalar-QED

When dense plasmas are exposed to intense fields, intrinsically relativistic-quantum effects such as pair production can happen. To faithfully capture such phenomena when scales are not well separated, a unique tool is provided by real-time lattice quantum electrodynamics (QED). As a toy model, we consider scalar-QED, which describes bosonic plasmas. This model can be solved, in the classical-statistic regime, by advancing an ensemble of statistically equivalent initial conditions in time using the Klein-Gordon-Maxwell (KGM) equations, for which we have developed a variational algorithm. To demonstrate the capability of our numerical scheme, we apply it to two example problems. The first example is the propagation of linear waves, whose numerical spectrum recovers the analytic wave dispersion relations. The second example is pair production when intense X-ray lasers interact with a dense plasma target, whereby we demonstrate natural transition from wakefield acceleration to pair production when the laser amplitude exceeds the Schwinger threshold.