Insulating antiferromagnets are anticipated as the main protagonists of ultrafast spintronics, with their intrinsic terahertz dynamics and their abililty to transport spin information over long distances. However, direct transfer of spin angular momentum to an antiferromagnetic insulator at picosecond time scales remains to be demonstrated. Here, studying the ultrafast behaviour of ferromagnetic metal/antiferromagnetic insulator bilayers, we evidence the generation of coherent excitations in the antiferromagnet combined with a modulation of the demagnetization behavior of the ferromagnet. This confirms that magnetic information can indeed be propagated into antiferromagnetic spin waves at picosecond timescales, thereby opening an avenue towards ultrafast manipulation of magnetic information.
@article{arxiv.2407.14787,
title = {Terahertz antiferromagnetic dynamics induced by ultrafast spin currents},
author = {Sanjay René and Artem Levchuk and Amr Abdelsamie and Zixin Li and Pauline Dufour and Arthur Chaudron and Florian Godel and Jean-Baptiste Moussy and Karim Bouzehouane and Stéphane Fusil and Vincent Garcia and Michel Viret and Jean-Yves Chauleau},
journal= {arXiv preprint arXiv:2407.14787},
year = {2024}
}