Scattering of a magnetostatic surface spin wave from a one-dimensional step potential in a ferromagnetic film

Abstract

As the research on magnetostatic surface spin waves (MSSWs) gains momentum, a concrete understanding of how these waves behave at interfaces is still undeveloped. In this work, we theoretically investigate how a MSSW traveling in a ferromagnetic film scatters across a sharp step of magnetic parameters in the film such as the applied field. An integral equation is derived, which describes the scattering process. We solve this equation both directly numerically and using a second Born approximation. We find that scattering produces partial reflection and partial transmission of the wave through the step. A nontrivial behavior of the amplitude of the transmitted wave as a function of the step size is observed in the calculation and analyzed.

Controlling the propagation of dipole-exchange spin waves using local inhomogeneity of the anisotropy

“…where ˆ( ) exc G x is a Green's function of SW excitation by an external driving field. Its derivation is fully analogous to the one-dimensional cases [36,37]. Equating the denominator of the components of the Fourier transform of ˆ( ) exc G x to zero yields dispersion relations (kx) for the fundamental and the first exchange SW modes.…”

“…As shown in Refs. [36][37][38], the problem of scattering of SW from 1D defects can be cast in the form of a Born Equation. The Born Equation is an integral equation for the amplitude of a wave that undergoes scattering from an area (called a "defect" in the present manuscript), where the value of some parameter of the waveguiding medium is different from its value elsewhere.…”

“…The inverse Fourier transform of the analytical solution yields two components [36] -the far field in the form of a travelling SW (23) and the near field of the excitation source. No exact solution for the near field exists; but approximate solutions can be obtained for both MSSW and BVMSW cases in the form of combinations of exponents of complex arguments and exponential integrals [36,37]. Alternatively, the inverse Fourier transform can be carried out numerically on the same mesh.…”

“…In addition, the first volume mode (VM) that is quantized over the thickness of the films is shown with green color. Due to the rather small thickness of the films, the contribution of the exchange energy to the energy of the SWs is large enough to open up a gap between the fundamental mode and the VMs, leading to the absence of any direct mode crossing or hybridizations [21,25,37]. Note that this gap will be even larger for thinner films.…”

Analyzing the Effect of Magnetic Field Strength on the Behavior of Ferromagnetic Materials in United States

“…In China, research on the behavior of ferromagnetic materials is advancing, particularly in the field of electronics and telecommunications. For example, a study by Li (2019) investigated the magnetic properties of ferromagnetic thin films for use in magnetic sensors and data storage devices. Through careful analysis of the magnetic susceptibility and hysteresis loop characteristics, the researchers aimed to optimize the performance and reliability of these devices.…”