Voltage-Controlled Dynamic Modulation of Electromagnetic Response in Antiferromagnetic Materials at Terahertz Frequencies

Antiferromagnetic materials have recently attracted interest due to advantages including high resonance frequencies up to terahertz, and the possibility of electrically modulating the magnetic properties such as the anisotropy makes them excellent candidates for energy-efficient devices. In this study, we theoretically applied such features on the dynamic manipulation of electromagnetic responses with a broad tunable spectral range. Dielectric antiferromagnets with strong magneto-electric/-elastic coupling were considered, which can achieve robust control of perpendicular magnetic anisotropy with less dissipation than the metallic counterparts. Theoretical analysis based on motion equation was used to derive the frequency-dependent permeability and the resonance frequency of antiferromagnets for different biaxial anisotropy profiles and incident electromagnetic wave polarizations. Numerical calculations adopting typical parameters indicated that the resonance frequency modulation reaches tens of percent in the sub-mm wavelength range, along with the corresponding permeability change. Application to specific devices such as a bandpass filter further illustrated the validity of the concept.