Coupled kinetic Boltzmann electromagnetic approach for intense ultrashort laser excitation of plasmonic nanostructures

We propose a multiphysical computational approach that allows for efficient coupling of full-vector Maxwell-based propagation codes with kinetic Boltzmann equations to investigate the spatial dynamics of non-equilibrium processes in plasmonic nanostructures upon intense laser excitation. Accessing the energy-resolved electron distribution provides a direct path towards multidimensional modeling of transient optical, electron emission, and electron transport processes. Simulations are performed for a gold nanoparticle upon infrared ultrashort-pulse excitation close to the melting threshold, evidencing the interplay between strong intrinsic and (non)thermal nonlinearities and accessing simultaneously the non-equilibrium thermal and propagation dynamics. While delivering the results within a reasonable simulation time and while being open to further extensions, the proposed approach can serve as a reliable compromise between point quantum and space-dimensional classical models.