Regensburg 2013 – wissenschaftliches Programm
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DF: Fachverband Dielektrische Festkörper
DF 22: Poster II
DF 22.4: Poster
Freitag, 15. März 2013, 10:30–13:30, Poster D
Treshold magnetic circular dichroism as a contrast mechanism for imaging magnetization dynamics of thin films — •Maximilian Staab, Hans-Joachim Elmers, Mathias Kläui, and Gerd Schönhense — Johannes Gutenberg-Universität, 55099 Mainz, Germany
Investigations of thin magnetic films like Co/Pt or Co/Au promise novel findings to overcome existing limits of data storage devices. Threshold magnetic circular dichroism (MCD) in photoemission is a phenomenon which allows gathering information about the details of the electronic structure near EF [1]. Photons generated from a femtosecond laser excite electrons at the magnetic surface and eject them from the material. The yield of electrons is directly influenced by the relative orientation of the magnetization direction of the surface layer and the helicity of the incoming photons. By changing the helicity one obtains yield asymmetries of the order of 10% and more, making threshold MCD a great contrast mechanism for imaging dynamical processes in magnetic materials.
The combination of photoemission electron microscopy with MCD sensitivity and a femtosecond laser setup is capable of investigating magnetization dynamics with great spatial and time resolution. The process of ultrafast demagnetization and the current-induced domain wall motion by spin torque transfer are two very interesting phenomena which will be explored.
Project funded by DFG EL172/15.
[1] K. Hild et al., Phys. Rev. B 82, 195430 (2010)