Berlin 2015 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 35: Magnetization / Demagnetization Dynamics II
MA 35.3: Vortrag
Mittwoch, 18. März 2015, 15:30–15:45, EB 301
Electron kinetics in ultrafast magnetization dynamics — •Benedikt Y. Mueller1, Bärbel Rethfeld2, and Manfred Fähnle1 — 1Max-Planck-Institute for Intelligent Systems, Heisenbergstrasse 3, 70569 Stuttgart, Germany — 2Technical University of Kaiserslautern, Germany
When a ferromagnetic metal is excited by an ultrashort laser pulse, a demagnetization within less than one picosecond is observed [1]. Up to now, no microscopic theory explains the large variety of this effect [1-3] on equal footing. As a step towards this goal, we investigate the ultrafast demagnetization by a kinetic approach, applying Boltzmann collision integrals [4-8] to trace the dynamics of the electrons [6,7]. For Nickel, we investigate the contribution of electron-electron and electron-phonon spin-flip scattering to the total demagnetization effect. Moreover, we illustrate the thermalization and relaxation processes after laser irradiation. As a result, we find that a dynamic electron band structure is essential for describing ultrafast demagnetization [6].
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[3] Koopmans, B. et al., Nature Materials 9, 259 (2010)
[4] Rethfeld et al., Phys. Rev. B 65, 214303 (2002)
[5] Mueller and Rethfeld, Phys. Rev. B 87, 035139 (2013)
[6] Mueller et al., Phys. Rev. Lett. 111, 167204 (2013)
[7] Illg et al., Phys. Rev. B 88, 214404 (2013)
[8] Essert and Schneider, Phys. Rev. B 84, 224405 (2011)