Directional Spin Wave in Spin-Torque Oscillators Induced by Interfacial Dzyaloshinskii–Moriya Interaction

Spin-torque oscillators (STOs) have tunable frequencies, low energy consumption, and high-quality factor compared to traditional oscillators. Here, we report the characteristics of nanocontact-STOs in the presence of interfacial Dzyaloshinskii-Moriya interaction (DMI) based on micromagnetic simulations. The DMI can decrease the STO frequency by about 2 GHz. More importantly, the DMI is able to break the isotropy of the spin-wave spectrum and turn the emitted microwave into directional spin-wave beams, potentially facilitating the synchronization of multiple STOs.