Nonequilibrium Dynamics of Interacting Electrons, Phonons and Excitons from First Principles

Combining density functional theory with kinetic equations has advanced the modeling of ultrafast nonequilibrium dynamics in materials. After introducing this framework, I will present an approach to evolve in time the coupled electron and phonon Boltzmann transport equations. This parallel numerical scheme, parametrized with <i>ab initio</i> interactions, enables accurate studies of carrier and lattice dynamics, as well as simulation of time-domain absorption, diffraction and photoemission. Extensions to include strong electric fields and treat nonequilibrium exciton dynamics will be examined. Besides the methods, the talk will highlight scientific results achieved with this framework, including the discovery of a carrier relaxation asymmetry in semiconductors, accurate predictions of electron velocity-field curves, and mapping of the coupled exciton, valley and phonon dynamics in 2D transition metal dichalcogenides. I will conclude with a discussion of our open-source code, PERTURBO, enabling these calculations.