Magnetization reversal driven by low dimensional chaos in a nanoscale ferromagnet

Abstract

Energy-efficient switching of magnetization is a central problem in nonvolatile magnetic storage and magnetic neuromorphic computing. In the past two decades, several efficient methods of magnetic switching were demonstrated including spin torque, magneto-electric, and microwave-assisted switching mechanisms. Here we report the discovery of a new mechanism giving rise to magnetic switching. We experimentally show that low-dimensional magnetic chaos induced by alternating spin torque can strongly increase the rate of thermally-activated magnetic switching in a nanoscale ferromagnet. This mechanism exhibits a well-pronounced threshold character in spin torque amplitude and its efficiency increases with decreasing spin torque frequency. We present analytical and numerical calculations that quantitatively explain these experimental findings and reveal the key role played by low-dimensional magnetic chaos near saddle equilibria in enhancement of the switching rate. Our work unveils an important interplay between chaos and stochasticity in the energy assisted switching of magnetic nanosystems and paves the way towards improved energy efficiency of spin torque memory and logic.

References in corpus (19)

• Spin torque building blocks
• Coherent Signal Amplification in Bistable Nanomechanical Oscillators by Stochastic Resonance
• Electrical Detection of Magnetization Dynamics via Spin Rectification Effects
• Laser Chimeras as a paradigm for multi-stable patterns in complex systems
• Phase Coherent Precessional Magnetization Reversal in Micro-scopic Spin Valve Elements
• Route to chaos in optomechanics
• Potential implementation of Reservoir Computing models based on magnetic skyrmions
• Macromagnetic simulation for reservoir computing utilizing spin dynamics in magnetic tunnel junctions
• Stochastic resonance of a nanomagnet excited by spin transfer torque
• Large-angle, gigahertz-rate random telegraph switching induced by spin-momentum transfer
• Spin torque ferromagnetic resonance with magnetic field modulation
• Attempt frequency of magnetization in nanomagnets with thin-film geometry
• Efficient Switching of 3-Terminal Magnetic Tunnel Junctions by the Giant Spin Hall Effect of ${\mathrm{Pt}}_{85}{\mathrm{Hf}}_{15}$ Alloy
• Transient chaos - a resolution of breakdown of quantum-classical correspondence in optomechanics
• Spin-transfer assisted thermally activated switching distributions in perpendicularly magnetized spin valve nanopillars
• Time Domain Mapping of Spin Torque Oscillator Effective Energy
• Tunable Transient Decay Times in Nonlinear Systems: Application to Magnetic Precession
• Transient chaos and fractal structures in planetary feeding zones
• Role of spin-transfer torques on synchronization and resonance phenomena in stochastic magnetic oscillators

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• Pattern generation and symbolic dynamics in a nanocontact vortex oscillator
• Bifurcation structure and chaos in nanomagnet coupled to Josephson junction
• Input-driven chaotic dynamics in vortex spin-torque oscillator
• Chaotic Antiferromagnetic Nano-Oscillator driven by Spin-Torque
• Parametric resonance of spin waves in ferromagnetic nanowires tuned by spin Hall torque
• Bifurcation to complex dynamics in largely modulated voltage-controlled parametric oscillator
• Large angle precession of magnetization maintained by a microwave voltage
• Time crystal and chaos in the hybrid atom-optomechanics system
• Chaotic magnetization dynamics driven by feedback magnetic field
• Feedback voltage driven chaos in a three-terminal spin-torque oscillator
• Breather bound states in a parametrically driven magnetic wire
• Josephson-like magnetic tunnel junction -- transition from classical to quantum regime