Berlin 2015 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 20: POSTER Ib
MA 20.10: Poster
Dienstag, 17. März 2015, 09:30–13:00, Poster A
Transport effects and ultrafast magnetization dynamics in laser-excited metals — •Linda Thesing1, Benedikt Y. Mueller2, and Baerbel Rethfeld1 — 1Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Germany — 2Max-Planck-Institut fuer Intelligente Systeme, Stuttgart, Germany
The equilibration of intense thermodynamic variables has been found to dominate ultrafast magnetization dynamics [1]. In itinerant ferromagnets, these variables may be considered separately for spin-up and spin-down electrons. The temporal evolution of electron and phonon temperatures as well as chemical potentials can be described with help of the µT model [2], which is based on a phenomenological two temperature description. The µT model has identified the minimum of magnetization as a transient equilibrium state. It also explains the experimentally observed slowing down of the magnetization dynamics by a critical region in the magnetic phase diagram [2]. Considering spatial effects, the excitation of a ferromagnetic sample with an ultrashort laser pulse does not only result in gradients of electron temperatures but also of the chemical potential of the electrons. The µT model allows to trace the equilibration of such gradients, and additionally accounts for transport effects such as Seebeck or Peltier effect. Therefore, it opens the possibility to describe ultrafast magnetization dynamics driven by different chemical potentials [1] and transport effects.
[1] B. Y. Mueller et al., PRL 111, 167204 (2013)
[2] B. Y. Mueller and B. Rethfeld, PRB 90, 144420 (2014)