Magnonic Metamaterials for Spin-Wave Control with Inhomogeneous Dzyaloshinskii–Moriya Interactions

Abstract

A magnonic metamaterial in the presence of spatially modulated Dzyaloshinskii–Moriya interaction is theoretically proposed and demonstrated by micromagnetic simulations. By analogy to the fields of photonics, we first establish magnonic Snell’s law for spin waves passing through an interface between two media with different dispersion relations due to different Dzyaloshinskii–Moriya interactions. Based on magnonic Snell’s law, we find that spin waves can experience total internal reflection. The critical angle of total internal reflection is strongly dependent on the sign and strength of Dzyaloshinskii–Moriya interaction. Furthermore, spin-wave beam fiber and spin-wave lens are designed by utilizing the artificial magnonic metamaterials with inhomogeneous Dzyaloshinskii–Moriya interactions. Our findings open up a rich field of spin waves manipulation for prospective applications in magnonics.

Collective Spin-Wave Dynamics in Gyroid Ferromagnetic Nanostructures

“…As a result, a satisfactory fit of the Kittel curve to the gyroidal resonance signal for different sample orientations relative to the CPW (see Figure S4 in the Supporting Information) was obtained using M eff = 0.275 M s = 132 kA/m, and g eff = 1.028 g = 2.2, as shown in Figure b,c with a white dotted line. Such findings suggest that the given 3D structure exhibits magnonics’ metamaterial-like properties, so far considered only for the planar structures, − capable of modulating (specifically, decreasing) the effective saturation magnetization and the dynamical response of the structure in a methodical and foreseeable manner. The effective magnetization, which is higher than expected with only a 10% filling fraction, implies that the gyroid structure may have anisotropy.…”

Stripe Domains in Electrodeposited Ni90fe10 Thin Films

“…In addition, there is an increasing attention in magnetoelasticity since it can be exploited in spin waves generation [3][4][5][6]. Spin waves are collective excitations of the electron spin system, and they have been proposed for applications such as information transfer with low energy dissipation, high-speed technology or analog computing [3,[7][8][9][10]. In that sense, spin textures play a fundamental role for the stabilization and manipulation of spin waves, and therefore, a huge effort is performing for the development of tunable magnetic structures.…”

Editorial for the Special Issue “Nanoscale Ferroic Materials—Ferroelectric, Piezoelectric, Magnetic, and Multiferroic Materials”

“…Magnetic metamaterials are deemed to be a promising candidate as a high-quality information carrier. Since the graded magnonic refractive index can be created by modification of the material properties, Zhuo et al [ 7 ] theoretically propose a ferromagnet/heavy metal bilayer magnonic metamaterial, and modulate the refractive index of spin waves with the inhomogeneous Dzyaloshinskii–Moriya interaction (DMI). The authors further study spin-wave refraction and reflection at the interface between two magnetic media with different DMI and build a generalized Snell’s law of spin waves.…”