Nikolai G. Kovshikov

Observation of dipole spin wave envelope solitons in ferromagnetic films

The formation of spin-wave (SW) envelope solitons was observed in experiments on dipolar SW (or magnetostatic wave) propagation in yttrium-iron-garnet (YIG) films magnetized at a small angle ( theta /sub e/ >

Excitation of bright and dark microwave magnetic envelope solitons in a resonant ring

The excitation of both bright and dark microwave magnetic envelope solitons has been realized for one and the same resonant ring containing a yttrium–iron–garnet film magnetostatic wave (MSW) delay line. The resonant ring modifies the MSW character to produce a series of frequency intervals with alternating regions of positive and negative dispersion. These alternating regions support bright and dark soliton production, respectively.

Parametric frequency conversion with amplification of a weak spin wave in a ferrite film

We report on experiments of parametric frequency conversion of a weak signal spin wave by a copropagating strong pump spin wave. An effective spin-wave frequency conversion with amplification occurred when the carrier frequencies of the co-propagating waves were in the spectral region of high negative dispersion in the dipole-exchange spin-wave spectrum of the film. A theoretical explanation of the observed phenomenon is given in terms of a four-wave parametric interaction process.

Observation of the amplification of spin-wave envelope solitons in ferromagnetic films by parallel magnetic pumping

The propagation of envelope solitons of microwave-frequency spin waves in a spatially periodic field oriented parallel to the magnetic pump has been investigated experimentally. In a pulsed pumping regime with amplitude much greater than the threshold for parametric excitation of spin systems, amplification of spin-wave envelope solitons exceeding their natural damping was obtained.

Effect of magnetic dissipation on propagation of dipole spin-wave envelope solitons in yttrium iron garnet films

The results of direct experimental measurements of attenuation of a spin wave envelope soliton propagating in a high-quality yttrium-iron-garnet (YIG) film ( Delta H=0.3 Oe) are presented. It is shown that the envelope soliton attenuation is approximately two times larger than attenuation of the linear sinusoidal signal in the same film. >

Observation of parametric amplification of propagating dipole-exchange spin waves in yttrium iron garnet films

Amplification of a weak-signal spin wave by a strong pump spin wave propagating in an yttrium iron garnet film is observed for the first time. A theoretical explanation of the amplification phenomenon is suggested on the basis of the four-wave parametric processes.

Observation of spin-wave envelope dark solitons in ferromagnetic films

Microwave spin-wave envelope dark solitons were experimentally observed for the first time. Dark solitons with zero minimum amplitude were generated by two-frequency excitation of input spin waves with a fixed amplitude. Nonlinear interaction between these two traveling waves gave rise to periodic sequences of dark solitons in a ferromagnetic film.

Observation of self-generation of dark envelope solitons for spin waves in ferromagnetic films

We have performed experiments in which self-generation of dark envelope solitons for spin waves at microwave frequencies were obtained. Stable self-generation of dark solitons was observed in a ring consisting of tangentially magnetized yttrium iron garnet film and a microwave signal amplifier.

Self-generation of spin-wave envelope soliton trains with different periods

The self-generation of periodic spin-wave envelope soliton trains of microwave spin waves in active rings based on ferromagnetic films is studied experimentally. The trains of bright solitons with different periods are self-generated in the same ring due to the frequency-selective control of the attenuation of spin waves circulating in an active ring.

Generation of spin-wave soliton-like pulse trains in yttrium iron garnet films under parallel pumping

Summary form only given. The parametric generation of spin wave (SW) bright envelope soliton-like pulse trains by microwave parallel pumping in yttrium iron garnet (YIG) films has been observed by Benner et al. (1999). We report that through parallel pumping different types of SW soliton-like pulse trains can be obtained. The experimental structure consisted of three parallel 50 /spl mu/m-wide microstrip transducers. The distance between the two outer transducers was chosen to be 1.2 mm. These transducers were fed in-phase and served as the pumping elements. The inner transducer, situated exactly in the middle of the structure, served as an output signal element. For the experiments we used a long and narrow, 50 by 2 mm, 5.7 /spl mu/m thick YIG film straight-edge resonator. It was centered over the transducer structure. The resonator was tangentially magnetized in the direction perpendicular to its long axis thus creating conditions for back and forth propagation of magnetostatic backward volume SW excitations. Periodical pulsed pumping with carrier frequency /spl omega//sub p/ of about 8.5 GHz, a repetition rate of about 3 MHz, and a pulse duration of 70-100 ns was applied to obtain soliton formation. The frequency spectra of the generated soliton trains were recorded simultaneously with the amplitude profiles.