An electric current flowing in a ferromagnetic metal carries spin angular momentum, i.e. it is spin-polarized. Here, we measure the spin-wave Doppler shift induced by the transfer of angular momentum from the diffusive spin-polarized electric current onto coherent spin waves in epitaxial MgO/Fe/MgO thin films. We follow this Doppler shift as function of the temperature and determine that the degree of spin-polarization of the current increases from 77% to 86% when cooling the device from 303K down to 10K. Interpreting these measurements within the two-current model, we separate the contributions from electron-surface, electron-phonon and electron-magnon scatterings to the spin-dependent resistivity of Fe.
@article{arxiv.2412.20531,
title = {Unraveling the temperature-dependent spin-polarized electron transport in iron via spin-wave Doppler shift},
author = {José Solano and Quentin Rossi and Jerome Robert and Marc Lenertz and Yves Henry and Benoit Gobaut and David Halley and Mattieu Bailleul},
journal= {arXiv preprint arXiv:2412.20531},
year = {2025}
}