Dzyaloshinskii‐Moriya Torque‐Driven Resonance in Antiferromagnetic α‐Fe2O3

Abstract

AbstractThe high‐frequency optical mode of α‐Fe2O3 is examined, and it is reported that Dzyaloshinskii−Moriya (DM) interaction generates a new type of torque on the magnetic resonance. Using a continuous‐wave terahertz interferometer, the optical mode spectra is measured, 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. This 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.