A magnetic insulator is an ideal platform to propagate spin information by exploiting magnon currents. However, until now, most studies have focused on Y3Fe5O12 (YIG) and a few other ferri- and antiferromagnetic insulators, but not on pure ferromagnets. In this study, we demonstrate for the first time that magnon currents can propagate in ferromagnetic insulating thin films of EuS. By performing both local and non-local transport measurements in 18-nm-thick films of EuS using Pt electrodes, we detect magnon currents arising from thermal generation by the spin Seebeck effect. By comparing the dependence of the local and non-local signals with the temperature (< 30 K) and magnetic field (< 9 T), we confirm the magnon transport origin of the non-local signal. Finally, we extract the magnon diffusion length in the EuS film (~140 nm), a short value in good correspondence with the large Gilbert damping measured in the same film.
@article{arxiv.2303.03833,
title = {Magnon currents excited by the spin Seebeck effect in ferromagnetic EuS thin films},
author = {M. Xochitl Aguilar-Pujol and Sara Catalano and Carmen González-Orellana and Witold Skowronski and Juan M. Gómez-Pérez and Maxim Ilyn and Celia Rogero and Marco Gobbi and Luis E. Hueso and Fèlix Casanova},
journal= {arXiv preprint arXiv:2303.03833},
year = {2024}
}