Regensburg 2019 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 2: Ultrafast magnetization effects and magnetization dynamics
MA 2.4: Vortrag
Montag, 1. April 2019, 10:15–10:30, H37
Dynamics of laser-excited nickel: an ultrafast look at the lattice side — •Daniela Zahn1, Thomas Vasileiadis1, Tim Butcher2, Yingpeng Qi1, Hélène Seiler1, Jan Vorberger2, and Ralph Ernstorfer1 — 1Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany — 2Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany
The behavior of ferromagnets after laser excitation is governed by the interplay of electrons, lattice and spins. In the case of 3d-ferromagnets, strong coupling between electrons and spins leads to ultrafast demagnetization on the femtosecond time scale [1]. Since the lattice drains energy from the electrons on similar timescales, it plays an important role in the magnetization dynamics. A method to study the lattice response directly is femtosecond electron diffraction (FED) [2]. We present FED results on nickel for a variety of excitation conditions. We compare the experimental data with ab-initio calculations of the spin-polarized electron-phonon coupling in combination with a two-temperature model. We find that the experimental results can only be described by the model if energy transfer to the spin system is taken into account.
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