Micromagnetic study of a spin-torque oscillator based on a magnetic nano-contact magnetized at an arbitrary angle

Abstract

The nature of spin wave modes excited by spin-polarized direct current in a spin-torque auto-oscillator based on a magnetic nanocontact was studied by a micromagnetic simulation in the case when the external bias magnetic field was rotated from the in-plane to perpendicular-to-plane orientation. In qualitative agreement with the weakly-nonlinear analytical theory it was found, that at a certain critical angle, an abrupt switching from the self-localized nonlinear "bullet" mode to a propagating quasi-linear Slonczewski mode takes place, and is accompanied by an upward jump in generated microwave frequency. It was, also, found that the analytical theory overestimates the magnitude of a critical magnetization angle, corresponding to the mode switching, and that the magnitude of the frequency jump caused by the mode switching is inversely proportional to the nanocontact radius.

27 pages, 5 figure, paper submitted to Physical Review B

References in corpus (7)

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Cited by in corpus (7)

• Spin transfer nano-oscillators
• Experimental evidence of self-localized and propagating spin wave modes in obliquely magnetized current-driven nanocontacts
• Spin Transfer Dynamics in Spin Valves with Out-of-plane Magnetized CoNi Free Layers
• Spin wave mode coexistence on the nano-scale: A consequence of the Oersted field induced asymmetric energy landscape
• Power and linewidth of propagating and localized modes in nanocontact spin-torque oscillators
• Combined frequency-amplitude nonlinear modulation: theory and applications
• Current induced multi-mode propagating spin waves in a spin transfer torque nano-contact with strong perpendicular magnetic anisotropy