Interplay of Linear and Nonlinear Localization Mechanisms in Spin-Torque Oscillators with a Field Well

  • R. V. Verba Institute of Magnetism Nat. Acad. of Sci. of Ukraine
Keywords: spin-torque oscillator, spin-wave bullet, localized mode, magnetization dynamics

Abstract

The magnetization dynamics in a spin-torque oscillator with nonuniform profile of a static magnetic field creating a field well is studied by analytic calculations and numerical simulations. It is demonstrated that, in the case of sufficiently deep and narrow field well, the linear localization in the field well dominates the nonlinear self-localization, despite a negative nonlinear frequency shift. A change of the localization mechanism results in a qualitatively different dependence of the generation power on the driving current. For the dominant linear localization, the soft generation mode is realized, while, for the nonlinear self-localization, we observe a hard mode of auto-oscillator excitation. Simultaneously, a difference in the profiles of the excited spin-wave mode can become evident and distinguishable in experiments only in the case of a nonsymmetric field well.

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Published
2019-11-01
How to Cite
Verba, R. (2019). Interplay of Linear and Nonlinear Localization Mechanisms in Spin-Torque Oscillators with a Field Well. Ukrainian Journal of Physics, 64(10), 947. https://doi.org/10.15407/ujpe64.10.947
Section
Physics of magnetic phenomena and physics of ferroics