# Temperature dependence of the non-local spin Seebeck effect in YIG/Pt nanostructures

## TL;DR

This study investigates how the non-local spin Seebeck effect in YIG/Pt nanostructures varies with temperature, revealing a temperature-dependent sign change and emphasizing the importance of interface transfer and magnon transport mechanisms.

## Contribution

It provides new insights into the temperature dependence of the non-local SSE and highlights the need to consider both interface transfer and magnon transport in models.

## Key findings

- Sign change of non-local SSE voltage at a characteristic separation d0 at room temperature.
- Strong temperature dependence of d0, indicating varying transport mechanisms.
- Both interface transfer and magnon transport are crucial for understanding the effect.

## Abstract

We study the transport of thermally excited non-equilibrium magnons through the ferrimagnetic insulator YIG using two electrically isolated Pt strips as injector and detector. The diffusing magnons induce a non- local inverse spin Hall voltage in the detector corresponding to the so-called non-local spin Seebeck effect (SSE). We measure the non-local SSE as a function of temperature and strip separation. In experiments at room temperature we observe a sign change of the non-local SSE voltage at a characteristic strip separation d0, in agreement with previous investigations. At lower temperatures however, we find a strong temperature dependence of d0. This suggests that both the angular momentum transfer across the YIG/Pt interface as well as the transport mechanism of the magnons in YIG as a function of temperature must be taken into account to describe the non-local spin Seebeck effect.