Goos-Hänchen shift of a spin-wave beam transmitted through anisotropic interface between two ferromagnets

Abstract

The main object of investigation in magnonics, spin waves (SWs) are promising information carriers. Presently the most commonly studied are plane wave-like SWs and SWs propagating in confined structures, such as waveguides. Here we consider a Gaussian SW beam obliquely incident on an ultra-narrow interface between two identical ferromagnetic materials. We use an analytical model and micromagnetic simulations for an in-depth analysis of the influence of the interface properties, in particular the magnetic anisotropy, on the transmission of the SW beam. We derive analytical formulas for the reflectance, transmittance, phase shift and Goos-Hänchen (GH) shift for beams reflected and refracted by an interface between two semi-infinite ferromagnetic media; the results for the refracted beam are the first to be reported to date. The GH shifts in SW beam reflection and transmission are confirmed by micromagnetic simulations in the thin-film geometry. We demonstrate the dependence of the characteristic properties on the magnetic anisotropy at the interface, the angle of incidence and the frequency of the SWs. We also propose a method for the excitation of high-quality SW beams in micromagnetic simulations.

Spin-Wave Phase Inverter upon a Single Nanodefect

“…Fabrication of magnonic waveguides. The Co-Fe waveguides were fabricated by FEBID employing the precursor HCo 3 Fe(CO) 12 . The precursors were injected in the SEM through a capillary with an inner diameter of 0.5 mm.…”

Comparison of spin-wave transmission in parallel and antiparallel magnetic configurations

“…Generally, the GH effect occurs when spin waves are scattered at the interface [36][37][38][39] , describing the shift between the reflected (or transmitted) point and the incident point. In the previous works, the sign of GH shifts can be positive or negative, depending on the reflection (or transmission) coefficients.…”

“…It's worth noting that spin waves are thermally excited by the spin Seebeck effect (SSE) in the experiments of magnon valves 20 and magnon junctions 21 , thus the coherence of spin waves is ignored. In fact, the coherence is important for spin-wave transmission because it can lead to plentiful physical phenomena, such as refraction [28][29][30][31][32][33][34] , skin effect 35 , Goos-Hänchen (GH) shift [36][37][38][39] , tunneling 40 , resonant tunneling 41,42 and resonant transmission [43][44][45][46] . Therefore, the systematic researches on the transmission of coherent spin waves in P and AP magnetic configurations are necessary, however few studies have reported on this issue.…”

Excitation and tailoring of diffractive spin-wave beams in NiFe using nonuniform microwave antennas

“…Here, the aim is to achieve maximum flexibility concerning manipulation such as steering of SWs with the ability to reduce the required footprint of a device while maintaining high-frequency operation [1]. So-called SW nano-optics [9] require the generation and manipulation of SW beams in the microwave frequency range and enable the realization of devices like SW fibers [10,11] or the exploitation of refraction and reflection effects [12][13][14]. Within the last few years, various approaches to generate SW beams were proposed and investigated.…”