Dresden 2003 – scientific programme
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MA: Magnetismus
MA 15: Hauptvortr
äge Gerrits / Lindner
MA 15.1: Invited Talk
Wednesday, March 26, 2003, 14:00–14:30, HSZ/04
Control of coherent magnetization reversal in micron-sized magnetic elements by magnetic-field-pulse-shaping — •Thomas Gerrits1, Hugo van den Berg1, Theo Rasing1, and Ludwig Baer2 — 1NSRIM Institute, Toernooiveld 1, 6525ED Nijmegen, The Netherlands — 2Siemens, CTMF 1, Paul-Gossen-Strasse, Erlangen, Germany
The presentation will deal with a technique that allows reversal of the magnetization by coherent rotation, initiated by single magnetic field pulse excitation. In addition this technique makes it possible to control the magnetization precession with picosecond precision using magnetic field pulse shaping. For the magnetic field-pulse-shaping we make use of two independently triggered GaAs photoswitches, excited by femtosecond-laser pulses. The optical set-up allows introducing two pump-laser-pulses, by which the shape of the current pulse and hence the field pulse can be modified. This is done by superimposing the two current pulses that were independently generated in two photoconductive switches. Both the mutual delay of the two pulses and their sign and magnitudes are variable parameters. We could show that controlling the precessional switching of a lithographically structured micron-sized permalloy element is possible, using magnetic field pulse shaping on picosecond time-scales and we have obtained a switching time of about 200ps