Regensburg 2019 – wissenschaftliches Programm
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 . 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) . 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.
Beaurepaire et al., PRL 76, 4250 (1996).
Waldecker et al., JAP 117, 044903 (2015).