Spectral Analysis of Subterahertz Oscillations Basedon an Antiferromagnet/Non-MagneticMetal Heterostructure

We present a model of a sub-THz frequency spectrum analyzer based on the antiferromagnet/non-magnetic metalheterostructure. The considered structure operates in the activ eself-oscillation regime with the high Q-factor (closed to106)andis phase-locked to the analyzed signal, while the frequency of theoscillator is linearly tuned by the spin-polarized current flowingthrough the non-magnetic metal. We find an analytical expressionfor the duration of the phase-locking interval by analyzing the gen-eralized Kuramoto model with inertia. We show that the speed ofthe described spectrum analyzer is comparable to and exceeds thespeed of modern commercial spectrum analyzers. The presented re-sults can be helpful for practically realizing the room-temperature,tunable, sensitive, and high-speed sub-THz frequency spectrumanalyzers.