Nonlinear transverse stabilization of spin-wave beams in magnetic stripes

Abstract

The propagation of spin-wave beams in ferromagnetic stripes has been investigated experimentally by means of spatially resolved Brillouin light scattering spectroscopy. It is shown that in the case of low-amplitude spin waves the diffraction and the transverse confinement of spin waves lead to oscillations of the beam width. The authors found that with increasing spin-wave amplitude the interplay between the linear diffraction and the repulsive spin-wave nonlinearity results in a suppression of the oscillations of the beam width and in its transverse stabilization.

Nonlinear Propagation of Spin Waves in Microscopic Magnetic Stripes

“…Note that nonlinear dynamics usually depends on the interplay between the nonlinear frequency shift and the dispersion. For the studied Damon-Eshbach waves this interplay results in the repulsive type of nonlinearity, which should lead to a nonlinear suppression of the transverse modulation and a stabilization of the SW beam at increased intensities, as was observed for macroscopic samples [21]. However, as one can see from Fig.…”

“…As was found for macroscopic magnetic samples [22], the presence of the nonlinear damping can reverse the action of the nonlinearity in such a way that phenomena typical for repulsive nonlinearity appear in magnetic systems characterized by the attractive one. Note here, that such a reversed action was observed for the attractive nonlinearity only, whereas the action of the repulsive nonlinearity was found not to be strongly affected by the nonlinear damping [21].…”

Linear and nonlinear spin-wave dynamics in macro- and microscopic magnetic confined structures

“…The spatial distributions of the spin-wave intensity in the beam propagating in a macroscopic waveguide are shown in figure 2 [38]. The shown distributions were obtained in a 1.5 mm wide YIG stripe by scanning an area with lateral dimensions of 1.6 mm × 5 mm with a step size of 0.1 mm.…”

Determining wave vector and material property from the phase-shift of spin-wave propagation

“…than the field where no surface spin-wave propagation mode is allowed), and subsequently subtracted from each other [5]. Similar techniques have been applied for spin-wave propagation investigation in conducting ferromagnetic films [5][6][7][8] and for effective permeability measurement [15][16][17]. The authors of refs.…”

“…[6]. References [7,8] used a Brillouin light scattering (BLS) method to study spin-wave modes and propagation. The difference from these techniques is that we convert the measured scattering matrices (S 11 , S 21 , S 12 , and S 22 ) directly into spin-wave propagation phase-shift, which allows us to conveniently extract spinwave propagation parameters, including wave vector k, phase velocity, and group velocity, as well as the in-plane anisotropy field and magnetization.…”