Electrodynamic Model of THz- Frequency Signal Source Based on Antiferromagnetic Spin Hall Auto-oscillator

Abstract

Electrodynamic model of a THz-frequency signal source utilizing an antiferromagnetic spin Hall oscillator (SHO), where the magnetization vectors of the antiferromagnet's (AFM) sublattices are canted inside the easy plane, resulting in the appearance of the small net magnetization vector, is proposed and analyzed. A bias dc electric current applied to the SHO creates a spin current that, being injected in the AFM layer, starts to rotate the net magnetization of the canted AFM with the THz frequency proportional to the injected spin current. This rotation of the small net magnetization results in the THz-frequency dipolar radiation that can be directly registered by an adjacent resonator. Our calculations show that the radiation power increases with the increase of frequency $f$ and could exceed $1 \mu W$ at $f$ ~ 0.5 THz for the case of a high-quality dielectric resonator coupled to the AFM layer.