Effects of the Zhang-Li Torque on Magnetic Droplet Solitons

Abstract

Spin-transfer nano-oscillators are devices in which spin-transfer torques can generate localized spin waves (dissipative solitons) called magnetic droplet solitons. We have studied the specific effects of the Zhang-Li torque on these solitons. To do so, we have analytically solved for an accurate electric current distribution and its Oersted fields and we have then used mumax3 to get the evolution of the magnetization. We have found that this torque either enlarges or shrinks droplets and also raises or lowers generation current thresholds depending on the configuration of the device. In addition, we have eventually outlined a method for controlling the relative impact of this torque