Regensburg 2025 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 37: Correlated Electrons: Poster

TT 37.45: Poster

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

Understanding Resonant Inelastic X-ray Spectroscopy Using Dynamical Mean-Field Theory and Model Hamiltonians — •Lukas Hellmann, Aleksandrs Zacinskis, Sina Shokri, Michelangelo Tagliavini, Kevin Ackermann, and Maurits W. Haverkort — Universität Heidelberg, Institut für Theoretische Physik, Philosophenweg 19, Heidelberg 69120 Germany

Using model Hamiltonians with local Coulomb interactions, we demonstrate how resonant inelastic X-ray scattering spectra (RIXS) can be interpreted within the framework of the dynamical mean-field approximation. Our approach incorporates both valence correlations and core-valence Coulomb repulsion, enabling a detailed examination of spectral features across the metal-insulator transition. The calculated RIXS spectra reveal two distinct types of excitations: (1) locally excited excitons exhibiting a resonant enhancement at constant energy loss, and (2) a fluorescence regime characterized by resonant intensity enhancement at constant emitted energy. We analyze the transition in intensity between these two excitation regimes and discuss its implications for understanding electronic dynamics. All calculations are performed directly on the real frequency axis using the software package Quanty (www.quanty.org). This methodology not only provides accurate predictions for RIXS spectra but also offers a versatile framework for studying the dynamics of other correlated systems.

Keywords: Resonant Inelastic X-ray Spectroscopy (RIXS); Dynamical Mean-Field Theory (DMFT); Metal-Insulator Transition; Excitons and Fluorescence; Correlated Electron Systems