# Focused ion beam modification of non-local magnon-based transport in yttrium iron garnet/platinum heterostructures

## TL;DR

This paper investigates how Ga ion beam modification affects local and non-local magnetotransport in yttrium iron garnet/platinum heterostructures, revealing the importance of magnons in non-local spin transport.

## Contribution

It demonstrates that cutting the yttrium iron garnet layer with a Ga ion beam suppresses non-local magnetoresistance, highlighting the role of magnons in spin transport.

## Key findings

- Non-local magnetoresistance vanishes after cutting the YIG layer.
- Local spin Hall magnetoresistance remains finite despite cutting.
- Magnons are essential for non-local spin transport in these heterostructures.

## Abstract

We study the impact of Ga ion exposure on the local and non-local magnetotransport response in heterostructures of the ferrimagnetic insulator yttrium iron garnet and platinum. In particular, we cut the yttrium iron garnet layer in between two electrically separated wires of platinum using a Ga ion beam, and study the ensuing changes in the magnetoresistive response. We find that the non-local magnetoresistance signal vanishes when the yttrium iron garnet film between the Pt wires is fully cut, although the local spin Hall magnetoresistance signal remains finite. This observation corroborates the notion that pure spin currents carried by magnons are crucial for the non-local magnetotransport effects observed in magnetic insulator/metal nanostructures.