Our research group develops novel methods to follow ultrafast processes in molecules and solid-state systems by means of light pulses employing analysis within quantum electrodynamics. We develop a theoretical and a computational framework to follow electron, exciton, spin, coupled electron- and exciton-nuclear by means of ultrashort x-ray pulses wiht (sub-)femtosecond time resolution and sub-nanometer spatial resolution. We consider time- and angle-resolved photoelectron spectroscopy, time- and momentum-resolved RIXS, and energy-resolved Bragg diffraction.
Seeing exciton in motion
The project "Seeing excitons in motion" funded by the Volkswagen Foundation aims to employ advances of attosecond x-ray science to photovoltaic applications. In the framework of this project, we describe how photovoltaic materials in the regime of exciton dynamics interact with ultrashort light pulses.
We consider exciton dynamics (coupled electron-hole dynamics) in both molecular and solid-state systems for photovoltaics.
Imaging laser-driven electron and spin dynamics
Within this research field, we develop techniques to image microscopic charge and spin rearrangements during the interaction of a crystal with an optical pulse. In particular, we use the Floquet formalism to describe the action of a pump pulse on a crystal beyond the perturbation theory. We describe how probe x-ray pulses interact with such laser-driven systems. Based on this analysis, we show how to retrieve information about charge and spin rearrangements of laser-driven systems on an atomic scale.