Ab Initio Description of Ultrafast Dynamics in Solids

Abstract

When we theoretically investigate interaction of an intense and ultrashort laser pulse with solids, there are two aspects that should be considered: the strong electric field of the light pulse induces extremely nonlinear electron dynamics in solids that cannot be described by perturbation theory. The nonlinear electron dynamics manifests as a nonlinear polarization in macroscopic scale that determines the propagation of the light pulse. Therefore, to describe the propagation of the intense light pulse, it is necessary to treat the coupled dynamics of the light electromagnetic fields and the electron dynamics. The scheme should also take into account the separation of the spatial scale of two dynamics. We have developed a theoretical and computational approach based on ab initio time-dependent density functional theory for interaction of strong and ultrashort laser pulse with solids and have applied the method to various phenomena. In my presentation, I will show our recent progresses of ab initio simulation in nano-optics.