Ultrafast electron dynamics in metals under laser irradiation

The evolution of the electron distribution in a metal irradiated by an ultr ashort laser pulse is described on the basis of numerical solution of the e quation-for the one-particle density matrix. The excitation mechanism is at tributed to the laser quanta absorption in electron collisions with both lo ngitude and transverse-acoustic phonons. It is shown that the absorption is mainly determined by the umklapp processes. The electron relaxation is due to electron-electron collisions taken into account using the relaxation-ti me approximation. The agreement with the experiment of Fann et al. [Phys. R ev. B 46, 13 592 (1992)] is good. [S0163-1829(99)04625-1].