Strong coupling antiferromagnetic resonance with sub-THz cavity fields

TL;DR

This paper demonstrates strong coupling between sub-THz cavity fields and antiferromagnetic spin waves in hematite at room temperature, revealing magnetic polaritons through transmission spectroscopy.

Contribution

It reports the first observation of strong coupling with antiferromagnetic spin waves in hematite above room temperature using a novel cavity setup.

Findings

Strong coupling achieved at room temperature

Formation of magnetic polaritons observed

Transmission spectra show clear coupling signatures

Abstract

Strong coupling of electromagnetic cavity fields with antiferromagnetic spin waves in hematite ($\alpha$-Fe$_2$O$_3$) was achieved above room temperature. A cube of hematite was placed in a metallic tube and transmission was measured, using a continuous-wave THz spectrometer. Spectra, collected as a function of temperature, reveal the formation of magnetic polaritons.