Dzyaloshinskii-Moriya torque-driven resonance in antiferromagnetic {\alpha}-Fe2O3

TL;DR

This paper investigates how Dzyaloshinskii-Moriya interaction influences high-frequency magnetic resonance in {\

Contribution

It introduces a novel method to measure DM interaction effects on antiferromagnetic resonance using terahertz spectroscopy.

Findings

Observed asymmetric absorption near the Morin transition.

Attributed spectral anomalies to DM interaction-induced torque.

Estimated the DM interaction field strength as 4 T.

Abstract

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.