Seminario impartido por Manuel Izquierdo, del European XFEL GmbH
The soft X-ray regime of the electromagnetic spectrum, 0.3 – 3 keV, enables resonant studies of many periodic table elements and related compounds with prospective technological applications. Performing soft X-ray experiments with femtosecond resolution allows addressing fundamental time scale dynamics. The ultimate goal is twofold: on the one hand, to disentangle the interplay between the different degrees of freedom in the system under investigation and on the other hand to develop coherent control for applications. Traditionally, femtosecond soft X-ray spectroscopy experiments have been limited to the photon-in/photon-out techniques. For some materials, the entanglement between the relevant degrees of freedom has been understood in a single experiment. Generalizing these observations to any class of material requires the use of a multi-messenger technique like photoelectron spectroscopy. The technique has been essential to understand the properties of complex materials, surfaces and interfaces. It provides simultaneous understanding of the electronic, spin, chemical and structural properties. The measured spectra generally contain information on the excitation spectrum and the excitation probabilities thanks to the many-body nature of the photoemission process. Furthermore, the intrinsic time scale of the photoelectric effect enables the study of the fundamental material dynamics. The technique has been successfully implemented down to the pico-second time resolution at synchrotrons. Femtosecond experiments are routinely done using high harmonic generation up to around 100 eV. The extension of the technique to higher photon energies is only possible using superconducting acceleration technology that produces femtosecond pulses at MHz repetition rates. In this contribution, the potentiality of femtosecond soft X-ray spectroscopy will be presented.
Ponente del seminario: Manuel Izquierdo
Fecha del seminario: 22/05/2024 12:00
Lugar del seminario: salón de actos IQF
