Regensburg 2013 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

MA: Fachverband Magnetismus

MA 49: Magnetization Dynamics III of 3

MA 49.2: Talk

Friday, March 15, 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.
E. Beaurepaire et al., Phys. Rev. Lett. 76, 4250 (1996)
M. Fähnle, C. Illg, J. Phys.: Condens. Matter 23, 493201 (2011)
D. Steiauf, C. Illg, M. Fähnle, J. Magn. Magn. Mater. 322, L5 (2010)
C. Illg, B. Meyer, M. Fähnle, Phys. Rev. B 86, 174309 (2012)