Relativistic Laser-Plasma Interactions in the Quantum Regime

We investigate the nonlinear interaction between a relativistically strong laser wave and a plasma in the quantum regime. The collective behavior of electrons is modeled by the Klein-Gordon equation, which is coupled nonlinearly to the electromagnetic wave equation and Poisson's equation for the electromagnetic vector and scalar potentials. This allows us to study the nonlinear interaction between an arbitrarily large amplitude electromagnetic wave and a quantum plasma. We study the importance of the quantum diffraction on the nonlinear dynamics of the system. The study has importance for the nonlinear interaction between super-intense X-ray laser light and solid density plasma, where quantum effects are important.