Probing nonlinear QED with strong laser fields

Program Description

Quantum electrodynamics exhibits a so-called critical field strength, where nonlinear and even nonperturbative quantum effects are expected to play an important role. This regime could be studied by combining strong lasers with highly energetic particles like in the seminal SLAC E-144 experiment. By investigating the nonlinear Breit-Wheeler process it is shown that the creation of matter from pure light in the fully nonperturbative regime is feasible with existing technology. An intuitive semiclassical model for the process is developed, revealing ample similarities with tunnel ionization in atomic physics. Furthermore, recollision processes and vacuum birefringence are examined.