Multiscale modeling of femtosecond laser irradiation on a copper film with electron thermal conductivity from ab initio calculation

Abstract

ABSTRACTBy combining the ab initio quantum mechanics (QM) calculation and the Drude model, electron temperature- and lattice temperature-dependent electron thermal conductivity is calculated and implemented into a multiscale model of laser material interaction, which couples the classical molecular dynamics (MD) and the two-temperature model (TTM). The results indicated that the electron thermal conductivity obtained from ab initio calculation leads to faster thermal diffusion than that using the electron thermal conductivity from empirical determination, which further induces a deeper melting region, a larger number of density waves travelling inside the copper film, and more various speeds of atomic clusters ablated from the irradiated film surface.