Ultrafast dynamics of coupled electrons, phonons and excitons from first principles

Speaker:  Marco Bernardi, Caltech

Program Description:
Combining density functional theory with kinetic equations has advanced the modeling of ultrafast nonequilibrium dynamics in materials. After introducing this framework, I will present a numerical approach to evolve in time the coupled Boltzmann transport equations (BTEs) of electrons and phonons, parametrized with ab initio interactions, for times up to tens of picoseconds with a femtosecond time resolution. I will demonstrate how this framework can compute time-domain absorption, diffraction and photoemission with quantitative accuracy in bulk and two-dimensional materials. Extensions to treat materials with strongly bound excitons will also be examined. I will conclude by presenting our open source code, PERTURBO, enabling these calculations.