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ABSTRACT: The formation of microwave spin-wave envelope solitons in the ferrite film of yttrium iron garnet in the presence of strong
nonlinear damping has been experimentally found and investigated. The solitons are formed due to the four-wave interactions
of spin waves when the characteristic time of wave modulation-instability development is much shorter than the time for establishing
the generation of short-wavelength magnons. The presence of nonlinear damping allows the excitation of spin-wave envelope
solitons by means of long microwave pulses.
JETP Letters 07/2006; 83(11):488-492. · 1.35 Impact Factor
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Magnetics Conference, 2000. INTERMAG 2000 Digest of Technical Papers. 2000 IEEE International; 05/2005
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ABSTRACT: A thin-film resonator structure has been used for quantitative
measurements of ferromagnetic resonance foldover and the associated
bistable power response for yttrium iron garnet (YIG) thin films. The
resonator consisted of a 1-mm by 1-mm-square, 4.9 μm-thick epitaxial
YIG film on top of a 50 μm-wide, 3-mm-long microstrip transducer. A
static magnetic field of 3200 Oe was applied perpendicular to the film.
Low- order magnetostatic forward volume wave standing modes were excited
at low power levels in the -20-dBm range and detected as resonance dips
in reflected power versus frequency spectra over the range 4-5 GHz. At
powers in the 0- to +15-dBm range, these dips showed foldover and
bistable response characteristics for increasing and decreasing
frequency or power sweeps. The use of 1-10-μs-wide pulses instead of
continuous-wave (CW) excitation resulted in the consistent disappearance
of the foldover and bistability characteristics. The frequency sweep
pulse data at fixed power reproduced the down-sweep CW results, and the
pulse data for both increasing and decreasing power at fixed frequency
reproduced the increasing-power CW results. A quantitative theoretical
analysis demonstrates that observed foldover and bistable response
characteristics are much weaker than predicted from the classical
precession foldover mechanism proposed by Anderson and Suhl, in which
the decrease in the static component of the magnetization drives the
response. The up-sweep and down-sweep foldover frequency jumps both
occur sooner than predicted by this classical mechanism and the
calculated foldover profiles are much more severe than the data show
IEEE Transactions on Magnetics 12/1999; · 1.36 Impact Factor
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ABSTRACT: Interactions between different types of excitations in magnetic
domain walls in YIG single crystal plates are investigated by induction
and magnetooptic techniques. The behavior of translational and flexural
modes of the wall vibrations as a function of wall velocity was found to
be asymmetric. The flexural mode amplitudes and eigenfrequencies for
positive and negative wall velocities are not equal, and the dynamic
structures of the wall moving at positive and negative velocities are
found to be essentially different. The character of both asymmetries was
reversed by changing the wall polarity. Various nonlinearities in highly
excited domain walls were studied, including the appearance of multiple
discrete harmonics as well as a continuous component of the Fourier
spectrum of the wall vibration signal and the corresponding changes of
its mobility and dynamic structure
IEEE Transactions on Magnetics 06/1993; · 1.36 Impact Factor
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ABSTRACT: Nonlinear flexural and translational vibrations of a single polarized domain wall in yttrium-iron-garnet, generated by repetitive rf pulses of a driving magnetic field have been investigated by the inductive technique. The unstable growth of the wall vibration amplitude was observed in the real-time signal as well as in the amplitude-frequency curves. This instability displays hysteresis with respect to the amplitude and frequency of the field and is dependent on the pulse period to pulse duration ratio. It was directly proved that the observed nonlinearities are determined by the interaction between the moving domain wall and the local potential well formed by dynamic defects responsible for the magnetic after-effect. A step change in the wall position caused by an additional dc field results in the step rise in the wall vibration amplitude followed by a slow decay with the time constant ∽ 50 ms. The spatial width of the potential well is also estimated experimentally to be less than the wall width (1 μm).
Journal of Magnetism and Magnetic Materials.
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ABSTRACT: Domain wall standing flexural waves in yttrium iron garnet single crystal plates are investigated by magnetooptical method. A number of nonlinear changes of the wall excitation spectrum is found and qualitatively explained.
http://dx.doi.org/10.1051/jphyscol:19888855.
