Magnonic crystal based forced dominant wavenumber selection in a spin-wave active ring

TL;DR

This paper demonstrates how a magnonic crystal in a spin-wave active ring can reliably and predictably control the dominant wavenumber, overcoming the sensitivity issues of traditional systems.

Contribution

It introduces a magnonic crystal-based method for forced dominant wavenumber selection in spin-wave active rings, with theoretical prediction and experimental validation.

Findings

Magnonic crystal enables robust wavenumber control.

Theoretical model accurately predicts mode enhancement conditions.

Experimental results confirm consistent mode selection.

Abstract

Spontaneous excitation of the dominant mode in a spin-wave active ring -- a self-exciting positive-feedback system incorporating a spin-wave transmission structure -- occurs at a certain threshold value of external gain. In general, the wavenumber of the dominant mode is extremely sensitive to the properties and environment of the spin-wave transmission medium, and is almost impossible to predict. In this letter, we report on a backward volume magnetostatic spin-wave active ring system incorporating a magnonic crystal. When mode enhancement conditions -- readily predicted by a theoretical model -- are satisfied, the ring geometry permits highly robust and consistent forced dominant wavenumber selection.