Karl Franzens University Graz

Graz University of Technology 

Ab initio simulation of laser-matter interaction: From microscopic to macroscopic
Prof. Kazuhiro Yabana
Center for Computational Sciences - University of Tsukuba, Guest Professor at TU Graz
16:15 - 17:15 Tuesday 16 December 2025 TUG HS P2

Theories and calculations of interaction between light and matter have traditionally developed along two separate paths: calculations of linear susceptibilities such as dielectric function based on quantum mechanics, and calculations of light propagation using macroscopic Maxwell's equations. However, the development of high-intensity, ultra-short pulse laser technology and/or light-matter interaction in nanomaterials, nanophotonics, has led to significant research progress in areas where such a separation between the micro and macro scales is no longer feasible. We have been developing a method to describe electron dynamics in matter in real time and real space using first-principles quantum mechanical calculations—specifically, time-dependent density functional theory (TDDFT). Furthermore, we have directly coupled this with Maxwell's equations, developing computational methods to describe light propagation without relying on constitutive relations via dielectric functions. In this talk, I will explain the theoretical and computational aspects of this method and present its applications to some nonlinear and ultrafast phenomena such as attosecond science and to nanophotonics.