Quantum description of charge fluctuations in electron gas and plasma waveresponse to intense laser interaction

A self-consistent model to simulate the dynamics of charge fluctuations in collisionless fermion gas is described, where the collective aspect of inte raction in many-particle charge distributions is taken into consideration. As an application we investigate the dynamics of the degenerate electron ga s of a thin Cu metal film, subject to an intense and ultra-short UV laser p ulse in resonance with the electron plasma frequency of the system. Results of simulation show that a collective excitation of electrons by resonance absorption leads to the formation of plasma waves in the metal film. The pr ocess is accompanied by the appearance of a third harmonic in the photon em ission spectrum.