Dresden 2026 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 46: Ultra-fast Phenomena II
HL 46.6: Vortrag
Donnerstag, 12. März 2026, 16:45–17:00, POT/0051
Probing Ultrafast Electronic and Lattice Dynamics simultaneously at the Atomic Scale with Time-Resolved Diffraction Anomalous Fine Structure (TR-DAFS) — •Moritz Meißner1,2,6, T. C. Rossi2, M. Rössle2, C. Petersen3, H. von Wenckstern3, R. Mandal4, M. Levantino5, and R. M. van der Veen2,6 — 1Paul-Drude-Institut für Festkörperelektronik — 2Helmholtz Zentrum Berlin — 3Universität Leipzig — 4Institut des materiaux de Nantes Jean Rouxel — 5European Synchrotron Radiation Facility — 6Technische Universität Berlin
This work presents the first successful demonstration of Time-Resolved Diffraction Anomalous Fine Structure (TR-DAFS) measurements carried out in a pump-probe (stroboscopic) scheme. We show that TR-DAFS can directly probe ultrafast structural and electronic dynamics in crystalline materials. Investigating Zinc oxide (ZnO) enables direct comparison between TR-DAFS at the Zn K-edge with time-resolved X-ray absorption spectroscopy (TR-XAS) data. TR-DAFS represents a leap forward in the study of photoexcited materials at the atomic scale by providing access to different aspects of lattice dynamics in resonant and non-resonant parts of the spectrum. Preliminary ab initio calculations show that the electronic changes visible in the resonant part of the spectrum are associated with an increase of carrier temperature in the photoexcited state. This dual sensitivity to electronic and lattice degrees of freedom makes TR-DAFS a game-changer in investigating ultrafast processes in complex materials and heterostructures as represented by the results of this work.
Keywords: ultra-fast; pump-probe; diffraction anomalous fine structure; elecronic dynamics; structural dynamics