Berlin 2008 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 26: Spin Dynamics / Spin -Torque II
MA 26.6: Vortrag
Donnerstag, 28. Februar 2008, 15:45–16:00, EB 301
Storage and parametrically stimulated recovery of microwave signal using standing spin-wave modes of a magnetic film — •Alexander Serga1, Andrii Chumak1,2, Alexander André1, Gennadiy Melkov2, Andrei Slavin3, Sergej Demokritov4, and Burkard Hillebrands1 — 1FB Physik and FSP MINAS, TU Kaiserslautern, Germany — 2Taras Shevchenko University of Kiev, Ukraine — 3Oakland University, Rochester, MI, USA — 4Institut für Angewandte Physik, Westfälische Wilhelms-Universität Münster, Germany
Microwave signals stored for a long time in the form of standing spin-wave (SW) modes of the ferrite film were recovered by parametric pumping. The experiment was performed on an in-plane magnetized yttrium-iron-garnet film. The microwave signal was carried by a packet of surface spin waves that propagate transversely to the bias magnetic field. Near the points of hybridization between the lowest SW mode and the higher-order exchange-dominated SW modes this packet partially transforms into standing thickness modes of the film. A pumping pulse having a carrier frequency close to twice the frequency of one of the standing modes recovers the packet of propagated waves. The time of recovery, duration, and power of the recovered pulse signal were controlled by the pumping power. We propose a theory of non-stationary parametric amplification of the standing modes on the background of the thermal magnon bath, which provides a good qualitative explanation of the experimental results. The work was supported by the DFG, by the Ukrainian Fund for Fundamental Research, by the U.S. Army Research Office, and by the Oakland University Foundation.