Spin-orbit torque manipulation of sub-terahertz magnons in antiferromagnetic α-Fe2O3
Dongsheng Yang, Taeheon Kim, Kyusup Lee, Chang Xu, Yakun Liu, Fei Wang, Shishun Zhao, Dushyant Kumar, Hyunsoo Yang
Abstract
Abstract The ability to electrically manipulate antiferromagnetic magnons, essential for extending the operating speed of spintronic devices into the terahertz regime, remains a major challenge. This is because antiferromagnetic magnetism is challenging to perturb using traditional methods such as magnetic fields. Recent developments in spin-orbit torques have opened a possibility of accessing antiferromagnetic magnetic order parameters and controlling terahertz magnons, which has not been experimentally realised yet. Here, we demonstrate the electrical manipulation of sub-terahertz magnons in the α -Fe 2 O 3 /Pt antiferromagnetic heterostructure. By applying the spin-orbit torques in the heterostructure, we can modify the magnon dispersion and decrease the magnon frequency in α -Fe 2 O 3 , as detected by time-resolved magneto-optical techniques. We have found that optimal tuning occurs when the Néel vector is perpendicular to the injected spin polarisation. Our results represent a significant step towards the development of electrically tunable terahertz spintronic devices.