Regensburg 2010 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 14: Spin Dynamics / Spin Torque I

MA 14.11: Vortrag

Mittwoch, 24. März 2010, 12:15–12:30, H10

Fluence and temperature dependent studies of femtosecond magnetism — •Oliver Schmitt, Tobias Roth, Daniel Steil, Sabine Alebrand, Mirko Cinchetti, and Martin Aeschlimann — Department of Physics and Research Center OPTIMAS, TU Kaiserslautern, Germany

We exploit the time-resolved magneto-optical Kerr effect (TRMOKE) to gain access to the physics underlying ultrafast spin-dynamics. In this contribution, external parameters like the pump pulse fluence and the ambient temperature are deliberately varied over a wide range. The won results for a thin nickel film demonstrate a strong temperature dependence on the maximum quenching q of the magnetization as well as on the demagnetization constant τ_m and the relaxation back to the initial state. The Elliott-Yafet (EY) spin-flip mechanism is the most promising candidate to explain the ultrafast loss of magnetic order. Experimental results are discussed behind the background of the two recent models for ultrafast demagnetization based on EY scattering [1,2].

B. Koopmans, G. Malinowski, F. Dalla Longa, D. Steiauf, M. Fähnle, T. Roth, M. Cinchetti and M. Aeschlimann, Nature Mater., accepted
M. Krauß, T. Roth, S. Alebrand, D. Steil, M. Cinchetti, M. Aeschlimann and H. C. Schneider, PRB 80, 180407(R) (2009)