Improved spectral stability in spin transfer nano-oscillators: single vortex versus coupled vortices dynamics

Abstract

We perform a comparative study of spin transfer induced excitation of the gyrotropic motion of a vortex core with either uniform or vortex spin polarizers. The microwave output voltage associated with the vortex dynamics, detected in both cases, displays a strong reduction of phase fluctuations in the case of the vortex polarizer, with a decrease of the peak linewidth by one order of magnitude down to 200kHz at zero field. A thorough study of rf emission features for the different accessible vortex configurations shows that this improvement is related to the excitation of coupled vortex dynamics by spin transfer torques.

References in corpus (5)

• Current-driven vortex oscillations in metallic nanocontacts
• Generation linewidth of an auto-oscillator with a nonlinear frequency shift: Spin-torque nano-oscillator
• Excitation of spin dynamics by spin-polarized current in vortex state disks
• Decoherence and mode-hopping in a magnetic tunnel junction-based spin-torque oscillator
• Nonlinear behavior and mode coupling in spin transfer nano-oscillators

Cited by in corpus (1)

• Stress-induced modification of gyration dynamics in stacked double-vortex structures studied by micromagnetic simulations