Regensburg 2019 – wissenschaftliches Programm
MA 36.4: Vortrag
Mittwoch, 3. April 2019, 15:45–16:00, H53
First principles studies of XAS/XMCD experiments in 2D heterostructures under steady-state non-equilibrium conditions — •Alberto Marmodoro, Masako Ogura, Sebastian Wimmer, and Hubert Ebert — Ludwig-Maximilians-Universität, München, Germany
We report on progress in the field of ab initio theoretical spectroscopy for out-of-equilibrium scenarios. This regime can be approached through either pump-probe experiments, or the application of a steady-state, time independent but finite external perturbation.
We consider here the case of XAS/XMCD investigations in multi-layer compounds subjected to a finite electric field . These techniques allow for high selectivity in the chemical element and even local environment being targeted. In combination with various kinds of theoretical sum rules, this can lead to fundamental insight on basic electronic structure features of a material.
Our computational framework is based on a fully relativistic multiple scattering / KKR Green function solution scheme for the basic SCF-DFT problem, and the simulation of various kind of spectroscopy and transport experiments. We put to the test a combination of recent developments for the non-equilibrium extension of this basic formalism  with established procedures for the study of x-ray absorption in bulks or 2D heterostructures.
 R. Kukreja et al., PRL 115, 096601 (2015); G. van der Laan, Physics 8, 83 (2015).  S. Achilles et al., PRB 88, 125411 (2013); M. Ogura, H. Akai, JPSJ 85, 104715 (2016)