Spin transfer nano-oscillator based on synthetic antiferromagnetic skyrmion pair assisted by perpendicular fixed magnetic field

Abstract As the microwave generator, the spin transfer nano-oscillator (STNO) based on skyrmion is promising to be one of the next generation spintronic devices. However, there still exist a few limitations to the possibility for practical application. In this paper, we propose a new STNO based on synthetic antiferromagnetic (SAF) skyrmion pair assisted by perpendicular fixed magnetic field. It is found that the oscillation frequency of this kind of STNO can reach up to 5.0 GHz, and multiple oscillation peak with higher frequency can be realized under fixed out-of-plane magnetic field. Further investigation showed that the skyrmion stability is improved by bilayer antiferromagnetic coupling, which guarantee the stability process of skyrmion under higher spin polarized current density. Our results provide the alternative possibilities for designing new skyrmion-based STNO to further improving the oscillation frequency, and realizing the output of multiple frequency microwave signal.