Inelastic spin-wave beam scattering by edge-localized spin waves in ferromagnetic thin film

TL;DR

This paper theoretically investigates inelastic scattering of spin-wave beams by edge-localized spin waves in ferromagnetic thin films, revealing frequency shifts and angular dependencies that enable potential magnonic signal demultiplexing.

Contribution

It introduces a novel theoretical analysis of inelastic spin-wave scattering at film edges, highlighting effects useful for magnonic signal processing.

Findings

Inelastic spin-wave scattering causes frequency shifts of the scattered beams.

Angular shift of scattered beams depends strongly on edge mode frequency.

Proposes magnonic demultiplexing based on inelastic scattering effects.

Abstract

Spin waves are promising chargeless information carriers for the future, energetically efficient beyond-CMOS systems. Among many advantages there are the ease of achieving nonlinearity, the variety of possible interactions, and excitation types. Although the rapidly developing magnonic research has already yielded impressive realizations, multi-mode nonlinear effects, particularly with the propagating waves and their nanoscale realizations, are still an open research problem. We study theoretically the dynamic interactions of the spin waves confined to the edge of a thin ferromagnetic film with the spin-wave beam incident at this edge. We found the inelastically scattered spin-wave beams at frequencies increased and decreased by the frequency of the edge spin-wave relative to the specularly reflected beam. We observed a strong dependence of the angular shift of the inelastic scattered spin-wave beam on the edge-mode frequency, which allowed us to propose a magnonic demultiplexing of the signal encoded in spin waves propagating along the edge. Since dynamic magnetostatic interactions, which are ubiquitous in the spin-wave dynamics, are decisive in this process, this indicates the possibility of implementing the presented effects, also in other configurations and their use in magnonic systems.