Chaos and strange attractors of magnons observed by parallel pumping (invited)

Journal Article · Tue Nov 15 04:00:00 UTC 1988 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.342379· OSTI ID:6749408

Yamazaki, H

Parallel-pumping experiments in two ferromagnets, YIG and (CH/sub 3/NH/sub 3/)/sub 2/CuCl/sub 4/ (abbreviated as MACC) have been performed at a pumping frequency of 9 GHz band at liquid-helium temperatures. Above the spin-wave instability threshold, auto-oscillations of magnon number which include period-doubling and period-halving bifurcations, chaos, and periodic windows are observed. From experimental time-series data, return maps, fractal dimensions, positive Lyapunov exponents, phase space portraits of strange attractors, and two-dimensional Poincare sections are obtained. A Lyapunov exponent is one of the quantitative measures of a strange attractor. Lyapunov exponents are obtained by analyzing experimental return maps as 0.34 for YIG and 0.21 for MACC. Phase space trajectories, i.e., strange attractors, are constructed by the conventional time-delay method. The successive Poincare sections of the strange attractors exhibit the stretching and folding effects of sheets of trajectories which confirms the fractal characteristics of the strange attractors. The fractal dimensions of the attractors are obtained by the correlation integral method to be 2.0 for YIG and 2.3 for MACC.

• Research Organization: Department of Physics, Faculty of Science, Okayama University, Tsushima-naka-3, Okayama 700, Japan
• OSTI ID: 6749408
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 64:10; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALKANES
AMMONIUM COMPOUNDS
CHALCOGENIDES
CHLORIDES
CHLORINE COMPOUNDS
COPPER CHLORIDES
COPPER COMPOUNDS
COPPER HALIDES
ELECTROMAGNETIC RADIATION
FERRITE GARNETS
FERROMAGNETIC MATERIALS
HALIDES
HALOGEN COMPOUNDS
HYDROCARBONS
IRON COMPOUNDS
IRON OXIDES
MAGNETIC MATERIALS
MAGNETIC PROPERTIES
MAGNETIZATION
MAGNONS
MATERIALS
METHANE
MICROWAVE RADIATION
MINERALS
NONLINEAR PROBLEMS
OPTICAL PUMPING
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PUMPING
QUASI PARTICLES
RADIATIONS
SILICATE MINERALS
SPIN WAVES
TRANSITION ELEMENT COMPOUNDS
ULTRALOW TEMPERATURE