Regensburg 2013 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 49: Magnetization Dynamics III of 3

MA 49.2: Vortrag

Freitag, 15. März 2013, 09:45–10:00, H22

The ultrafast demagnetization-time and -rate of Ni after laser pulse irradiation within the Elliott-Yafet theory — •Christian Illg, Michael Haag, and Manfred Fähnle — Max-Planck-Institut für Intelligente Systeme, Heisenbergstr. 3, 70569 Stuttgart, Germany

It is well known that a thin Ni film demagnetizes within about 100 fs after irradiation with a strong fs laser pulse [1]. Several mechanisms have been proposed which try to explain this effect but until now the underlying mechanism is still unclear [2].

We use the Elliott-Yafet theory which has the electron-phonon scattering as underlying mechanism and which we have extended to ferromagnets [3]. We calculate the demagnetization-time and -rate in Ni by using the ab-initio spin-density-functional theory (realistic electronic states) and an ab-initio force-constant model [4] (realistic phonon states). Finally, we compare the results with experimental data for low laser fluences.

Furthermore, the total angular momentum conservation during the demagnetization process is discussed thoroughly.
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