Dresden 2006 – scientific programme
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MA: Magnetismus
MA 18: Spin-Dynamics, Magnetization Reversal I
MA 18.6: Talk
Tuesday, March 28, 2006, 11:30–11:45, HSZ 403
Fast Resonant Vortex Core Switching — •H. Stoll1, A. Puzic1, K.W. Chou1, B. Van Waeyenberge2, T. Tyliszczak3, I. Neudecker4, K. Rott5, H. Brückl6, D. Weiss4, G. Reiss5, C.H. Back4, and G. Schütz1 — 1MPI for Metals Research, Stuttgart — 2Ghent University — 3LBNL, Berkeley, CA — 4Regensburg University — 5Bielefeld University — 6ARCS, Nano System Technology, Vienna
New ways were developed to switch the out-of-plane polarization of vortex cores in micron-sized ferromagnetic vortex structures either (i) by altering the amplitude of an alternating magnetic field at a frequency close to the eigenfrequency of the gyrotropic vortex motion or (ii) by applying a short burst (e.g., one single period) of this resonant ac magnetic field. Switching of the vortex core corresponds to a change of the chirality or handedness of the vortex structure. Experiments were performed on 1 to 2 micron large, 50 nm thick Permalloy circles and squares located on a Cu stripline. The polarization of the vortex core was detected with a scanning transmission X-ray microscope (STXM, ALS, Berkeley) by monitoring the sense of rotation of the vortex motion [1]. Magnetic vortex cores have already been discussed as candidates for magnetic data storage, but for switching of the vortex core polarization large magnetic fields in the order of half a Tesla were required so far [2,3]. The resonant vortex core switching schemes presented here need much lower magnetic fields (in the order of 10 mT) and allow in addition high switching speeds.
[1] A. Puzic et al., J. Appl. Phys. 97, 10E704 (2005)
[2] T. Okuno et al., J. Appl. Phys. 95, 3612 (2004)
[3] A. Thiaville et al., Phys. Rev. B 67, 094410 (2003)