Shock-wave-like emission of spin waves induced by the interfacial Dzyaloshinskii-Moriya interaction

We investigated spin wave (SW) propagation and emission in thin film systems with strong interfacial Dzyaloshinskii-Moriya interaction (DMI) utilizing micromagnetic simulation. The effect of DMI on SW is analogous to the flow magnetic medium leading Doppler effect, a spin-polarized current can enhance or suppress it. It demonstrated that, for velocity exceeding critical value, shock-wave-like SWs cone-shape emerges from magnetically irregular point as cone apex. angle quantitatively determined by DMI-induced velocity. Combining current, constant static source demonstrated, which provides promising route efficiently generate tunable frequency.