On-Off Intermittency in Randomly Driven Parallel Pumping |
A. Krawiecki Institute of Physics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw, Poland |
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A model of parallel pumping with many interacting parametric spin-wave pairs is investigated numerically. On-off intermittency is obtained in the time series of absorption when the rf field amplitude is varied randomly in time, slowly in comparison with the rf field frequency, and when its mean value exceeds slightly the parallel pumping instability threshold. If the interactions between parametrically and thermally excited spin waves are neglected, only one parametric spin-wave pair is strongly excited and exhibits intermittent behaviour. In the opposite case a packet of parametric spin waves with frequencies close to half the pumping frequency may be excited. This modifies quantitatively, but not qualitatively the intermittency characteristics in the presence of thermal noise. |
DOI: 10.12693/APhysPolA.92.465 PACS numbers: 05.45.+b, 76.50.+g, 75.30.Ds |