Maxwell + First-Principles TDDFT-MD Multi-Scale Simulation and Application to Impulsive Stimulated Raman Scattering Spectroscopy

Nonlinear optics in solids includes complex physics arising from coupled nonlinear dynamics of light electromagnetic fields, electrons, and phonons. We have developed a novel multi-scale simulation method to trace coupled dynamics of electromagnetic field inside the material in macroscopic scale and electrons and atoms in solid in microscopic scale, where the Maxwell equations are solved to describe propagation of the light while first-principles Ehrenfest molecular dynamics (MD) calculation is performed based on time-dependent density functional theory (TDDFT), extending our previously developed multi-scale method.
We have applied the method to impulsive stimulated Raman scattering spectroscopy of diamond. Simulations of pump and probe pulse propagations mimicking the experimental measurement process are performed using our developed open source free software, SALMON. We show detailed dynamical processes of generation of coherent phonon and amplification of Raman scattered wave as well as measured transmission signals.