Regensburg 2010 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 17: Spin Dynamics / Spin Torque II
MA 17.11: Vortrag
Mittwoch, 24. März 2010, 17:15–17:30, H10
Vortex dynamics in arrays of dipolar coupled ferromagnetic disks — •Andreas Vogel1, André Drews1,2, Markus Bolte1,2, and Guido Meier1 — 1Institut für Angewandte Physik und Zentrum für Mikrostrukturforschung, Universität Hamburg, Jungiusstrasse 11, 20355 Hamburg, Germany — 2AB Technische Informatik Systeme, Department Informatik, Universität Hamburg, Vogt-Kölln-Strasse 30, 22527 Hamburg, Germany
Vortices trapped in small ferromagnetic structures are of intense scientific interest because of their sub-nanosecond dynamics and potential technological applications as ultra-fast and high density digital storage elements [1-2]. We study the influence of the magnetostatic interaction on the vortex dynamics in arrays of ferromagnetic disks by means of a broadband ferromagnetic-resonance setup using a vector-network analyzer. Transmission spectra reveal a strong dependence of the frequency of resonant circular vortex-core motion on the inter-element distance within the array. For decreasing distance, a considerable broadening of the absorption peak is observed following a sixth-order power law, known from the Van der Waals type interaction. The experimental data are in accordance with analytical and numerical calculations using the rigid vortex model [3-4]. Additionally, micromagnetic simulations give a deeper insight into the observed phenomena.
[1] T. Shinjo et al., Science 289, 930 (2000);
[2] R. P. Cowburn et al., Phys. Rev. Lett. 83, 1042 (1999);
[3] J. Shibata et al., Phys. Rev. B 67, 224404 (2003);
[4] J. Shibata and Y. Otani, Phys. Rev. B 70, 012404 (2004).