Feature of vortex core gyration affected by Dzyaloshinskii-Moriya interaction

The effects of Dzyaloshinskii-Moriya interaction (DMI) on vortex core gyration excited by an out-of-plane polarized current is investigated through micromagnetic simulation. The simulation results demonstrate that the DMI not only widens the current density range for gyration, but also greatly increases the frequency and velocity of gyration. On the premise that DMI is large enough and the vortex configurations can simultaneously be maintained, the stable gyration orbit changes from a circle, to a ring-like and to a bird-nest-like trajectory. Furthermore, by comparing the data of different-size nanodisks, it can be seen that the vortices in smaller and thinner disks can achieve higher velocity and larger amplitude gyration, while in larger and thicker disks, the magnetic vortices can obtain higher oscillation frequency. The conclusions in this research add to the potential applications of magnetic vortex in nano-oscillaors.