Nano-oscillator based on radial vortex by overcoming the switching of core

Abstract

The spin torque nano-oscillators (STNOs) have garnered significant interest as a potential nanosized microwave signal generator. However, the core of magnetic radial vortex may be annihilated at the edge with the large spin polarized current density, which leads to unstable STNOs. In this work, we propose new STNOs based on a magnetic radial vortex by overcoming the annihilation of core at the edge, which was realized by adding high magnetic crystal anisotropy materials on the boundary of the nanodisk. It is found that the oscillation frequency reaches up to 2.8 GHz through a circular motion of core of magnetic radial vortex, and the radial vortex-based STNOs have advantages of small size, lower driving current. Our result has important significance to design new STNOs and provide a possible candidate for designing of spintronic devices based on magnetic radial vortex.