Berlin 2012 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 15: Magnetization / Demagnetization Dynamics I
MA 15.7: Vortrag
Dienstag, 27. März 2012, 11:30–11:45, H 1012
Ab-initio investigation of the Elliott-Yafet electron-phonon mechanism in laser-induced ultrafast demagnetization — Karel Carva1,2, Marco Battiato1, and •Peter M. Oppeneer1 — 1Uppsala University, S-75120 Uppsala, Sweden — 2Charles University, CZ-12116 Prague, Czech Republic
The spin-flip Eliashberg function is calculated from first principles for ferromagnetic Ni to accurately establish the
contribution of Elliott-Yafet electron-phonon spin-flip scattering to Ni’s femtosecond laser-driven demagnetization.
This is used to compute the spin-flip probability and demagnetization rate for laser-created thermalized as well as non-equilibrium electron distributions /1/.
Increased spin-flip probabilities are found for thermalized electrons, but the induced demagnetization rate is extremely small. A larger electron-phonon mediated demagnetization rate is obtained for non-equilibrium electron distributions, but its contribution is too small to account for the observed
femtosecond demagnetization.
/1/ K. Carva, M. Battiato, P.M. Oppeneer, Phys. Rev. Lett. 107, 207201 (2011).