Regensburg 2010 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 14: Spin Dynamics / Spin Torque I

MA 14.9: Vortrag

Mittwoch, 24. März 2010, 11:45–12:00, H10

Modelling of ultrafast laser-induced demagnetization — •Benedikt Müller, Mirko Cinchetti, Tobias Roth, Martin Aeschlimann, and Bärbel Rethfeld — University of Kaiserslautern, Germany

Experiments with ultrashort laser pulses irradiating ferromagnetic transition metals show a demagnetization on femtosecond timescale [1]. Despite the numerous experimental efforts, still no complete microscopic understanding of ultrafast magnetization dynamics have been achieved. In order to describe the microscopic processes we apply the Boltzmann equation including electrons and phonons which characterize a solid [2]. The model can be extended for a ferromagnetic material: We consider electrons with spin up and down separately and allow coupling between both reservoirs. Including this, we are able to describe changes in the magnetization by incorporating the spin dependence into the Boltzmann equation. With this model we describe the temporal evolution of a ferromagnetic material which is strongly excited by an ultrashort laser pulse.

[1] M. Cinchetti et al., PRL 97, 177201 (2006)

[2] B. Rethfeld et al., PRB 65, 214303 (2002)