Spin Hall nano-oscillators based on synthetic skyrmions imprinted in Co nanodisc

Abstract

Spin Hall nano-oscillators utilizing the synthetic spin textures imprinted in nanomagnets are demonstrated by numerical investigations. The imprinting is achieved by locally manipulating the magnetic anisotropy and the interfacial Dzyaloshinskii–Moriya interaction (DMI). The resulting spin texture is equivalent to a Néel-type skyrmion and is topologically stable to thermal fluctuations at finite temperatures. The eigenoscillation of the synthetic skyrmion can be activated by the spin-orbit torques induced by the spin Hall effect, and an eigenfrequency of up to ∼1.5 GHz is achieved. The eigenmode of the skyrmion resonance is found to be associated with the counter-clockwise rotational motion of the local magnetization. Our result demonstrates the working principle of using synthetic nanomagnets in spintronics applications.