Regensburg 2019 – wissenschaftliches Programm

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

MA: Fachverband Magnetismus

MA 2: Ultrafast magnetization effects and magnetization dynamics

MA 2.12: Vortrag

Montag, 1. April 2019, 12:30–12:45, H37

Linking spectroscopy calculations with the underlying time-dependent DFT electronic structure — •Voicu Popescu, Sergiy Mankovskiy, Jürgen Braun, Alberto Marmodoro, and Hubert Ebert — Department Chemie, Ludwig Maximilian University, Munich, Germany

Recent developments in time-dependent density functional theory (TD-DFT) paved the way towards investigating and quantitatively interpreting, on ab initio level, the ultrafast demagnetisation processes in ferromagnetic systems caused by a strong laser pulse [1]. These time-dependent phenomena can in principle be monitored by standard spectroscopic techniques such as angle-resolved photoemission (ARPES) and/or magnetic circular X-ray dichroism (MCXD), with the latter having the additional advantage of being element-specific.

The present contribution tries to answer the question how much of information, and how accurately, do such spectroscopy experiments actually convey? We do this by calculating, within the framework of the spin-polarised relativistic Korringa-Kohn-Rostoker method, the ARPES and MCXD spectra for several transition metals employing the self-consistently determined TD-DFT potentials. We make a side-by-side comparison between the theoretically determined spectra and the time evolution of the underlying electronic structure and find that, while correctly reproducing the qualitative trends, quantitative estimations based on the MCXD sum rules have a limited range of validity.

[1] K. Krieger et al., J. Chem. Theory Comput. 11, 4870 (2015)