Characterization of spin wave propagation in (111) YIG thin films with large anisotropy

TL;DR

This paper investigates spin wave propagation in (111) YIG thin films, emphasizing the importance of magnetic anisotropy fields for accurately determining the wavenumber in all-electrical experiments.

Contribution

It introduces a method to accurately determine spin wave wavenumber in YIG films by accounting for magnetic anisotropy fields, aligning experimental results with electromagnetic simulations.

Findings

Magnetic anisotropy fields significantly affect wavenumber determination.

Experimental wavenumber values match simulations when anisotropy is considered.

The method improves the design of spin wave devices using YIG films.

Abstract

We report on long-range spin wave (SW) propagation in nanometer-thick yttrium iron garnet (YIG) film with an ultralow Gilbert damping. The knowledge of a wavenumber value $|\vec{k}|$ is essential for designing SW devices. Although determining the wavenumber $|\vec{k}|$ in experiments like Brillouin light scattering spectroscopy is straightforward, quantifying the wavenumber in all-electrical experiments has not been widely commented upon so far. We analyze magnetostatic spin wave (SW) propagation in YIG films in order to determine the SW wavenumber $|\vec{k}|$ excited by the coplanar waveguide. We show that it is crucial to consider the influence of magnetic anisotropy fields present in YIG thin films for precise determination of SW wavenumber. With the proposed methods we find that experimentally derived values of $|\vec{k}|$ are in perfect agreement with that obtained from electromagnetic simulation only if anisotropy fields are included.