Electronic nonequilibrium effect in ultrafast-laser-irradiated solids

0585129 - FZÚ 2025 RIV US eng J - Journal Article
Medvedev, Nikita
Electronic nonequilibrium effect in ultrafast-laser-irradiated solids.
Physica Scripta. Roč. 99, č. 1 (2024), č. článku 015934. ISSN 0031-8949. E-ISSN 1402-4896
R&D Projects: GA MŠMT LTT17015; GA MŠMT(CZ) LM2023068; GA MŠMT(CZ) EF18_053/0016627
Grant - others:OP VVV - Mobility FZU 2(XE) CZ.02.2.69/0.0/0.0/18_053/0016627
Research Infrastructure: e-INFRA CZ - 90140
Institutional support: RVO:68378271
Keywords : hybrid model * multiscale model * Monte Carlo * Boltzmann equation * tight binding * molecular dynamics * noneuqilibrium kinetics
OECD category: Optics (including laser optics and quantum optics)
Impact factor: 2.9, year: 2022
Method of publishing: Open access

This paper describes the effects of electronic nonequilibrium in a simulation of ultrafast laser irradiation of materials. The simulation scheme based on tight-binding molecular dynamics, in which the electronic populations are traced with a combined Monte Carlo and Boltzmann equation, enables the modeling of nonequilibrium, nonthermal, and nonadiabatic (electron-phonon coupling) effects simultaneously. The electron-electron thermalization is described within the relaxation-time approximation, which automatically restores various known limits such as instantaneous thermaliza tion (the thermalization time and Born-Oppenheimer(BO) approximation. The results of the simulation suggest that the non-equilibrium state of the electronic system slows down electron-phonon coupling with respect to the electronic equilibrium case in all studied materials: metals, semiconductors, and insulators. In semiconductors and insulators, it also alters the damage threshold of ultrafast nonthermal phase transitionsinduced by modification of the enteratomic potential due to electronic excitation.
Permanent Link: https://hdl.handle.net/11104/0352862