Berlin 2008 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
MA: Fachverband Magnetismus
MA 19: Spin Dynamics / Spin Torque I
MA 19.11: Vortrag
Mittwoch, 27. Februar 2008, 16:45–17:00, EB 301
Selective Vortex Core Switching by Applying Rotating Magnetic Fields — Michael Curcic1, •Bartel Van Waeyenberge1,2, Kang Wei Chou1, Arne Vansteenkiste2, Markus Weigand1, Vitalij Sackmann1, Aleksander Puzic1, Hermann Stoll1, Georg Woltersdorf3, Tolek Tylisczak4, Christian H. Back3, and Gisela Schütz1 — 1Max-Planck-Institut für Metallforschung, Stuttgart, Germany, — 2Departement of Subatomic and Radiation Physics, Ghent University, Gent, Belgium — 3Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Regensburg, Germany — 4Advanced Light Source, LBNL, Berkeley, USA
We report on the experimental observation of the switching of the vortex core polarization in sub-micron sized ferromagnetic Landau structures caused by rotating magnetic fields.
In contrast to linear field pulses which toggle the vortex core from its up to the down position or vice versa, rotating magnetic fields allow for a selective vortex core switching either to its up or to its down position depending on the sense of field rotation.
The experiments were performed on 500 nm wide, 50 nm thick Permalloy Landau structures. They were imaged by time-resolved scanning transmission X-ray microscopy (STXM, BL. 11.0.2, ALS Berkeley). Defined thresholds were observed for the field amplitudes needed to switch the vortex core. Surprisingly, the threshold for the CW rotating field and CCW rotating field differed significantly. Possible explanations for this 'symmetry breaking' will be discussed.