Maxwell-Vlasov-Uehling-Uhlenbeck simulation for coupled laser-electron dynamics in a metal irradiated by ultrashort intense laser pulses

The description of electron-electron scattering presents challenges in the microscopic modeling of the interaction of ultrashort intense laser pulses with solids. We extend the semiclassical approach based on the Vlasov equation [M. Tani , ] to account for dynamic electron-electron scattering by introducing the Vlasov-Uehling-Uhlenbeck (VUU) equation. We further couple the VUU equation with Maxwell's equations to describe the laser pulse propagation. We apply the present approach to simulate laser-electron interactions in bulk and thin-film aluminum, focusing on energy absorption and transport. Our calculation results reveal that electron-electron scattering affects energy absorption more significantly under p polarization than under s polarization, highlighting the role of the nonuniform surface potential. Our simulations also show that the energy transport extends beyond the optical penetration depth, which is consistent with observations in previous laser ablation experiments. The developed Maxwell-VUU approach is expected to advance the understanding of intense laser-material interactions not only as a cost-effective alternative to the time-dependent density functional theory (TDDFT), but also by incorporating fermionic two-body collisions whose description is limited in TDDFT.