Temperature tunable oscillator of THz-frequency signals based on the orthoferrite/heavy metal heterostructure

Abstract

There is a considerable interest in development and realization of the terahertz-frequency range oscillators and detectors. In this work a concept of temperature tunable THz oscillator is theoretically developed. As an active element we suggest holmium orthoferrite near its reorientational phase transition. We show that the heating of the orthoferrite spin system decreases the threshold of the DC electric-current required for self-oscillations due to the anisotropy constant reduction. Such concept of the temperature-tuning of magnetic properties can be applied for wide range of ferri- or antiferromagnets. We discuss a possibility of applying orthoferrite/heavy metal heterostructure as continuously tunable oscillators and detectors of THz-frequency signals.