Chaos in Magnetic Nanocontact Vortex Oscillators

Abstract

We present an experimental study of spin-torque driven vortex self-oscillations in magnetic nanocontacts. We find that above a certain threshold in applied currents, the vortex gyration around the nanocontact is modulated by relaxation oscillations, which involve periodic reversals of the vortex core. This modulation leads to the appearance of commensurate but also more interestingly here, incommensurate states, which are characterized by devil's staircases in the modulation frequency. We use frequency- and time-domain measurements together with advanced time-series analyses to provide experimental evidence of chaos in incommensurate states of vortex oscillations, in agreement with theoretical predictions.

arXiv comment5 pages, 4 figures

References in corpus (12)

• Spin Transfer Torques
• Physics and Applications of Laser Diode Chaos
• Current-driven vortex oscillations in metallic nanocontacts
• Bistability of vortex core dynamics in a single perpendicularly magnetized nano-disk
• Physical random bit generation from chaotic solitary laser diode
• Nanolithography based on real-time electrically-controlled indentation with an atomic force microscope for nanocontacts elaboration
• Magnetization reversal driven by low dimensional chaos in a nanoscale ferromagnet
• Understanding nanoscale temperature gradients in magnetic nanocontacts
• Regular and chaotic vortex core reversal by a resonant perpendicular magnetic field
• Direct observation of magnetization dynamics generated by nano-contact spin-torque vortex oscillators
• Chaotic dynamics in spin-vortex pairs
• Super-harmonic injection locking of nano-contact spin-torque vortex oscillators

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• Signal detection based on the chaotic motion of an antiferromagnetic domain wall
• Bifurcation to complex dynamics in largely modulated voltage-controlled parametric oscillator
• Chaotic magnetization dynamics driven by feedback magnetic field
• Chaotic spin precession in antiferromagnetic domain walls
• Feedback voltage driven chaos in a three-terminal spin-torque oscillator
• Nanocontact vortex oscillators based on Co${}_2$MnGe pseudo-spin valves
• Flicker and random telegraph noise between gyrotropic and dynamic C-state of a vortex based spin torque nano oscillator
• Learning-Performance Evaluation of a Physical Reservoir Based on a Vortex Spin-Torque Oscillator with a Modified Free Layer