We examine the high-frequency optical mode of {\alpha}-Fe2O3 and report that Dzyaloshinskii-Moriya (DM) interaction generates a new type of torque on the magnetic resonance. Using a continuous-wave terahertz interferometer, we measure the optical mode spectra, where the asymmetric absorption with a large amplitude and broad linewidth is observed near the magnetic transition point, Morin temperature (TM ~ 254.3 K). Based on the spin wave model, the spectral anomaly is attributed to the DM interaction-induced torque, enabling to extract the strength of DM interaction field of 4 T. Our work opens a new avenue to characterize the spin resonance behaviors at an antiferromagnetic singular point for next-generation and high-frequency spin-based information technologies.
@article{arxiv.2307.04135,
title = {Dzyaloshinskii-Moriya torque-driven resonance in antiferromagnetic {\alpha}-Fe2O3},
author = {Qiyao Liu and Taeheon Kim and Kyusup Lee and Dongsheng Yang and Dushyant Kumar and Fanrui Hu and Hyunsoo Yang},
journal= {arXiv preprint arXiv:2307.04135},
year = {2023}
}