Regensburg 2025 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 37: Correlated Electrons: Poster

TT 37.44: Poster

Mittwoch, 19. März 2025, 15:00–18:00, P4

Density Functional Theory-based Multiplet Ligand Field Theory Calculations of Ultrafast Pump-Probe Electron Dynamics in Correlated Materials — •Ruth Kaiser, Sina Shokri, and Maurits W. Haverkort — Heidelberg University, Institute for Theoretical Physics, Philosophenweg 19, 69120 Heidelberg, Germany

Ultrafast pump-probe spectroscopy allows one to study and steer quantum materials on their fundamental time-scales. In correlated molecules and solids a theoretical understanding is challenging and quantitative predictions how coherently driven excitations decohere is highly non-trivial. We have developed a recipe for quantitatively predicting pump-probe spectra, starting with a Hamiltonian on a basis of local Wannier orbitals derived from density-functional calculations, describing the charge-transfer in the system and, on top of that, we include the full local Coulomb repulsion [1]. Using non-linear response theory, we then calculate the time-resolved spectra, such as photo-emission spectroscopy, x-ray absorption spectroscopy and resonant inelastic x-ray scattering, which captures the pump-probe dynamics. Our routine can be used for different types of correlated materials, such as Mott-Hubbard and Charge-Transfer insulators as well as molecules [2, 3]. Furthermore, we show examples where we implemented our method for real materials like NiO and SF₆ and compare our results with experiments.

[1] PRB 85, 165113 (2012);

[2] PRL 128, 153001 (2022);

[3] PRA 108, 032816 (2023).

Keywords: Ultrafast; Pump-Probe; Spectroscopy; Correlated materials