We present a combined numerical, theoretical, and experimental study on stimulated three-magnon splitting in a magnetic disk in the vortex state. Our micromagnetic simulations and ...Brillouin-light-scattering results confirm that three-magnon splitting can be triggered even below threshold by exciting one of the secondary modes by magnons propagating in a waveguide next to the disk. The experiments show that stimulation is possible over an extended range of excitation powers and a wide range of frequencies around the eigenfrequencies of the secondary modes. Rate-equation calculations predict an instantaneous response to stimulation and the possibility to prematurely trigger three-magnon splitting even above threshold in a sustainable manner. These predictions are confirmed experimentally using time-resolved Brillouin-light-scattering measurements and are in a good qualitative agreement with the theoretical results. We believe that the controllable mechanism of stimulated three-magnon splitting could provide a possibility to utilize magnon-based nonlinear networks as hardware for neuromorphic computing.
We present the generation of whispering gallery magnons with unprecedented high wave vectors via nonlinear 3-magnon scattering in a μm-sized magnetic Ni_{81}Fe_{19} disc which is in the vortex state. ...These modes exhibit a strong localization at the perimeter of the disc and practically zero amplitude in an extended area around the vortex core. They originate from the splitting of the fundamental radial magnon modes, which can be resonantly excited in a vortex texture by an out-of-plane microwave field. We shed light on the basics of this nonlinear scattering mechanism from an experimental and theoretical point of view. Using Brillouin light scattering microscopy, we investigated the frequency and power dependence of the 3-magnon splitting. The spatially resolved mode profiles give evidence for the localization at the boundaries of the disc and allow for a direct determination of the modes wave number.
Time Refraction of Spin Waves Schultheiss, K; Sato, N; Matthies, P ...
Physical review letters,
2021-Apr-02, Letnik:
126, Številka:
13
Journal Article
Recenzirano
Odprti dostop
We present an experimental study of time refraction of spin waves (SWs) propagating in microscopic waveguides under the influence of time-varying magnetic fields. Using space- and time-resolved ...Brillouin light scattering microscopy, we demonstrate that the broken translational symmetry along the time coordinate results in a loss of energy conservation for SWs and thus allows for a broadband and controllable shift of the SW frequency. With an integrated design of SW waveguide and microscopic current line for the generation of strong, nanosecond-long, magnetic field pulses, a conversion efficiency up to 39% of the carrier SW frequency is achieved, significantly larger compared to photonic systems. Given the strength of the magnetic field pulses and its strong impact on the SW dispersion relation, the effect of time refraction can be quantified on a length scale comparable to the SW wavelength. Furthermore, we utilize time refraction to excite SW bursts with pulse durations in the nanosecond range and a frequency shift depending on the pulse polarity.
The influence of the nature of corrosive media on the corrosion resistance of the Fe
78.5
Ni
1.0
Mo
0.5
Si
14.0
B
6.0
amorphous ribbon metal alloy is investigated by using different electrochemical ...methods. We determine the electrochemical characteristics of the alloy in 0.5 M aqueous solutions of NaCl, HCl, KOH, and H
2
SO
4
at
T
= (293 ± 1)°K. It is shown that the corrosion resistance of the amorphous material strongly depends on the component composition of corrosive media. We observe the formation of dense passivation layers on the surfaces of Fe
78.5
Ni
1.0
Mo
0.5
Si
14.0
B
6.0
alloy in alkaline solutions.
The influence of the elemental composition of strip amorphous alloys Fe
80.0
Si
6.0
B
14.0
, Fe
78.5
Ni
1.0
Mo
0.5
Si
6.0
B
14.0
; Fe
73.1
Cu
1.0
Nb
3.0
Si
15.5
B
7.4
; Fe
51.7
Ni
21.7
Cr
6.2
Mo
0.6
...V
1.5
Si
5.2
B
13.1
on corrosion resistance in 0.5 M aqueous solutions of NaCl, HCl, and KOH at
T
= (293 ± 1) K was investigated. The high corrosion resistance of Fe
51.7
Ni
21.7
Cr
6.2
Mo
0.6
V
1.5
Si
5.2
B
13.1
and Fe
73.1
Cu
1.0
Nb
3.0
Si
15.5
B
7.4
alloys in aggressive environments was established. Electrochemical parameters obtained both by the method of cyclic voltammetry and electrochemical impedance spectroscopy (EIS) indicate the formation of more durable surface layers in a 0.5 M potassium hydroxide aqueous solution on these alloys. The Cl
–
ions (especially at low pH) under their long-term action are the more aggressive oxidizers of amorphous alloys compared to OH
–
ions. During the passivation film formation in highly aggressive environments such alloy elements, which do not participate in this process, actively dissolve, and the main film-forming elements accumulate under the film, thus improving its protective properties.
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