Dresden 2006 – wissenschaftliches Programm
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MA: Magnetismus
MA 27: Spin-Dynamics, Magnetization Reversal II
MA 27.8: Vortrag
Donnerstag, 30. März 2006, 12:00–12:15, HSZ 403
Phase control of spin wave parametric interaction — •A. Serga1, M. Kostylev1, T. Schneider1, B. Hillebrands1, and A. Slavin2 — 1Fachbereich Physik, TU Kaiserslautern, 67663 Kaiserslautern — 2Department of Physics, Oakland University, Rochester, MI, USA
Phase sensitive clipping of microwave pulses passed through a parametric non-adiabatic spin wave amplifier driven by pumping pulses of double frequency is discovered. It was known that intensive amplification of the input signal by any spin wave parametric amplifier takes place only for a short time interval immediately after the pumping pulse is switched on. After that, the signal is partially or fully suppressed due to the interaction with thermal spin waves excited by long-acting pumping. It was found that in non-adiabatic amplifier, where the pumping localization length is comparable to the signal carrier wavelength, the level of this suppression can be controlled in a wide range by changing the phase of pumping relative to the phase of the input signal. The phase control is possible because the influence of the parasitic thermal spin waves reveals itself mainly in misphasing between the signal spin wave and the pumping due to local decrease of magnitude of the static magnetization. Brillouin light scattering observation demonstrates that the parasitic waves are generated near the bottom of the spin wave spectrum apparently due to a kinetic instability of parametrically excited spin waves at half the pump frequency.
Financial support by the DFG under Hi380/13 is acknowledged.