Spin-wave propagation in ultra-thin YIG based waveguides

TL;DR

This study demonstrates that ultra-thin YIG waveguides support robust, long-distance spin-wave propagation with multi-mode behavior, confirmed through advanced spectroscopy techniques, highlighting their potential for magnonic device applications.

Contribution

It provides the first detailed analysis of spin-wave propagation in 20 nm thick YIG waveguides using PSWS and {b5}-BLS spectroscopy, revealing long-distance, multi-mode propagation despite fabrication imperfections.

Findings

Spin-wave propagation is robust in microfabricated YIG waveguides.

Propagation length reaches 25 μm at 45 mT magnetic field.

Multi-mode spin-wave propagation is confirmed by {b5}-BLS mapping.

Abstract

Spin-wave propagation in an assembly of microfabricated 20 nm thick, 2.5 {\mu}m wide Yttrium Iron Garnet (YIG) waveguides is studied using propagating spin-wave spectroscopy (PSWS) and phase resolved micro-focused Brillouin Light Scattering ({\mu}-BLS) spectroscopy. We show that spin-wave propagation in 50 parallel waveguides is robust against microfabrication induced imperfections. Spin-wave propagation parameters are studied in a wide range of excitation frequencies for the Damon-Eshbach (DE) configuration. As expected from its low damping, YIG allows the propagation of spin waves over long distances (the attenuation lengths is 25 {\mu}m at \mu$_{0}$H = 45 mT). Direct mapping of spin waves by {\mu}-BLS allows us to reconstruct the spin-wave dispersion relation and to confirm the multi-mode propagation in the waveguides, glimpsed by propagating spin-wave spectroscopy.