Dzyaloshinskii-Moriya Torque-Driven Resonance in Antiferromagnetic & alpha;-Fe2O3

The high-frequency optical mode of & alpha;-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 (T-M & AP; 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.

Automated summary

The high-frequency optical mode of α-Fe2O3 is studied, and it is found that Dzyaloshinskii-Moriya (DM) interaction generates a new type of torque on the magnetic resonance. The optical mode spectra is measured using a continuous-wave terahertz interferometer, and an asymmetric absorption with a large amplitude and broad linewidth is observed near the magnetic transition point, Morin temperature (T-M ≈ 254.3 K). Based on the spin wave model, the spectral anomaly is attributed to the DM interaction-induced torque, allowing for the extraction of a DM interaction field strength of 4 T. This work opens up a new avenue for characterizing spin resonance behaviors at antiferromagnetic singular points for next-generation and high-frequency spin-based information technologies.