Semiclassical electron and molecular dynamics simulation of laser-induced melting of silicon

Abstract

Semiclassical electron force field (eFF) model extended by introducing laser electric field has been examined by applying to laser-induced melting of silicon on picosecond time scale. The simulation is first examined in our previous study [Yamada, J. Chem. Phys., 161, 174112 (2024)] for electronic excitation process in 20 fs induced by ultrashort femtosecond laser pulse. The present work is a follow-up examination of the method. To better reproduce optical properties of solid and liquid states, effective electron masses are adjusted for each state, and a smooth switch between them is introduced. The present simulation has reasonably described atomistic and semiclassical electronic behaviors in excitation and relaxation processes in the melting induced by 100 fs to 3 ps laser pulses.