Modern photon and electron beam sources make it possible to probe excitation spectra in many systems, ranging from atoms and molecules to bulk materials and complex interfaces. The interpretation of the experimental data is, however, problematic without an adequate theoretical support. To address this, we develop theories for predicting and analyzing spectra measured in different experiments, as e.g. (angle-resolved) photoemission spectroscopy, magneto-optical spectroscopy, X-ray emission and X-ray absorption, electron energy loss spectra, as well as resonant inelastic X-ray scattering.
The topics of our interest are fundamental theory of spectroscopy, method development, as well as understanding of functional materials, for energy conversion and molecular electronics, or where complex interactions play a role. Examples are Li based batteries and Ru based catalysts for the productions of solar fuels and correlated oxides such as high-temperature superconductors. The theoretical tools we employ involve density functional theory (DFT), linear-response theory, dynamical mean field theory (DMFT), Mahan-Nozieres-De Dominicis theory, and multi-configurational methods used in quantum chemistry.
Name of Barbara’s project
Name of Jan’s project: Electron magnetic circular dichroism
Name of Olle’s project
Name of Peter’s project: Theory of ultrafast magneto-X-ray spectroscopy