Regensburg 2019 – wissenschaftliches Programm
MA 2.1: Vortrag
Montag, 1. April 2019, 09:30–09:45, H37
Ultrafast electron dynamics in the first-order phase transition of FeRh — •Federico Pressacco1, Dmytro Kutnyakhov2, Vojtech Uhlir3, Jon Ander Arregi3, Michael Heber2, Steinn Agustsson4, Davide Sangalli5, Andrea Marini5, Matteo Gatti6,7, Guenter Brenner2, Dmitry Vasilyev4, Fausto Sirotti6, and Wilfried Wurth1,2 — 1CFEL, Universität Hamburg, Germany — 2DESY,Hamburg, Germany — 3CEITEC BUT, Czech Republic — 4JGU Mainz, Germany — 5CNR-ISM,Roma, Italy — 6École Polytechnique, CNRS, France — 7European Theoretical Spectroscopy Facility (ETSF)
Time resolved photo-electron spectroscopy is one of the most powerful techniques to directly investigate the role of the electronic structure in phenomena such as superconductivity, and magnetization dynamics. It greatly benefits from recent developments of high repetition rate Free Electron Lasers (FLASH at DESY Hamburg) and advances in electron detectors such as momentum microscopes. Here we present a time-resolved study carried out at FLASH of the metamagnetic phase transition induced by laser excitation in FeRh with femtosecond resolution. We monitor the changes in the valence band related to the phase transition which at equilibrium takes place at 400 K from an antiferromagnetic to a ferromagnetic phase. The dynamics show a sub-picosecond transition of the electronic structure to the FM, pointing to a primary role of the electronic system in triggering the magnetic phase transition. Ab-initio calculation of the non-equilibrium electronic structure show good agreement with the observed phenomena.