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MA: Fachverband Magnetismus

MA 19: Poster I (Bio- and Molecular Magnetism/ Magnetic Particles and Clusters/ Micro- and Nanostructured Magnetic Materials/ Magnetic Materials/ Multiferroics/ Magnetic Shape Memory Alloys/ Electron Theory of Magntism/ Spincaloric Transport/ Magnetic Coupling and Exchange Bias/ Magnetization Dynamics/ Micromagnetism and Computational Magnetics)

MA 19.82: Poster

Tuesday, March 15, 2011, 10:45–13:00, P2

Ultrafast all-optical switching of magnetic domains using circular polarized laser light — •Alexander Haßdenteufel, Daniel Steil, Sabine Alebrand, Mirko Cinchetti, and Martin Aeschlimann — Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Germany

Magnetic switching is typically a continuous process that can be described as a damped precession of the magnetization in an external magnetic field. This process takes typically up to 1 ns. Recently it has been shown that it is possible to achieve magnetic switching within 100 fs [1,2]. This process is induced by circularly polarized ultrashort laser pulses, where the direction of this opto-magnetic switching is determined only by the helicity of light. In this contribution, the femtosecond laser-induced reversal mechanism of GdFeCo thin films is investigated by static Faraday measurements. In particular, we studied the dependence of the writing threshold by using a delayed pump-pump geometry where one of the pump pulses is linearly and the second circularly polarized. The obtained results allow to explain all optical switching as a collaborative process induced by pulse helicity and pulse fluence. The fluence dependency leads to a thermal effect. This means there is an ultrafast decrease of the sample magnetization, which is a condition for the following pure optical magnetic switching process induced by circularly polarized light. This work was supported by the European project UltraMagnetron (NMP3-SL-2008-214469).
Kimel, A. V. et. al. Nature 435, 2005, 655-657
Stanciu, PRL 99, 047601 (2007)