Stochastic Generation Regime of an Antiferromagnetic Spin Hall Oscillator

Abstract

Antiferromagnetic (AFM) spin Hall oscillators (SHOs) are novel DC current-biased spintronic devices capable to operate in the (sub-)THz-frequency band. These devices are now actively studying, for instance, the problems of possible mutual synchronization of such systems, their use for neuromorphic computing, and their synchronization to an external harmonic signal attract research interest. The next step is an investigation of the stochastic generation regime in SHO when the system generates stochastic oscillations, but not determined harmonic output. In this paper, we show that such a regime indeed exists in the investigated SHO system and can be tuned by choosing appropriate values of external signal frequency and its amplitude. Stochastic generation manifests itself as spike-like pulse generation with random time intervals between the pulses, while the average time interval between the pulses is about 10ps. This means that an AFM SHO can generate a random output signal at least ten times faster than other existing random generation systems. Hence, obtained results could be useful for the creation of ultra-fast spintronic devices for probabilistic calculations. In addition, such THz-frequency stochastic generators are the first of their kind, which pave the way for a lot of possible applications of antiferromagnets, both in the field of spintronics and electronics.