# Optimizing propagating spin wave spectroscopy

## TL;DR

This paper improves propagating spin wave spectroscopy by optimizing device design, de-embedding techniques, and introducing a new antenna to better measure magnetic properties like DMI in thin layers.

## Contribution

It presents optimized device configurations, addresses parasitic coupling issues, and introduces a novel antenna design for more accurate DMI measurements in thin magnetic films.

## Key findings

- De-embedding is necessary for wide magnetic strips.
- Smaller strips reduce antenna-antenna parasitic coupling.
- A new antenna design excites a single spin wave vector.

## Abstract

The frequency difference between two oppositely propagating spin waves can be used to probe several interesting magnetic properties, such as the Dzyaloshinkii-Moriya interaction (DMI). Propagating spin wave spectroscopy is a technique that is very sensitive to this frequency difference. Here we show several elements that are important to optimize devices for such a measurement. We demonstrate that for wide magnetic strips there is a need for de-embedding. Additionally, for these wide strips there is a large parasitic antenna-antenna coupling that obfuscates any spin wave transmission signal, which is remedied by moving to smaller strips. The conventional antenna design excites spin waves with two different wave vectors. As the magnetic layers become thinner, the resulting resonances move closer together and become very difficult to disentangle. In the last part we therefore propose and verify a new antenna design that excites spin waves with only one wave vector. We suggest to use this antenna design to measure the DMI in thin magnetic layers.