Voltage Controlled Energy Efficient Domain Wall Synapses with Stochastic Distribution of Quantized Weights in the Presence of Thermal Noise and Edge Roughness

Abstract

We propose energy efficient strain control of domain wall (DW) in a perpendicularly magnetized nanoscale racetrack on a piezoelectric substrate that can implement multi state synapse to be utilized in neuromorphic computing platforms. In conjunction with SOT from to a current flowing in the heavy metal layer, strain is generated by applying a voltage across the piezoelectric. Such a strain is mechanically transferred to the racetrack and modulates the Perpendicular Magnetic Anisotropy (PMA). When different voltages are applied (i.e. different strains are generated), it can translate the DW to different distances for the same current which implements different synaptic weights. We have shown using micromagnetic simulations that 5-state and 3-state synapse can be implemented in a racetrack that is modeled with natural edge roughness and room temperature thermal noise. Such strain-controlled synapse has an energy consumption of few fJs and could thus be very attractive to implement energy-efficient quantized neural networks, which has been shown recently to achieve near equivalent classification accuracy to the full-precision neural networks.

References in corpus (18)

• The design and verification of Mumax3
• Current-driven dynamics of chiral ferromagnetic domain walls
• Quantized Neural Networks: Training Neural Networks with Low Precision Weights and Activations
• Dynamics of Dzyaloshinskii domain walls in ultrathin magnetic films
• Neuromorphic computing with multi-memristive synapses
• Accurate deep neural network inference using computational phase-change memory
• Matching domain wall configuration and spin-orbit torques for very efficient domain-wall motion
• Hybrid spintronics and straintronics: A magnetic technology for ultra low energy computing and signal processing
• Bennett clocking of nanomagnetic logic using electrically induced rotation of magnetization in multiferroic single-domain nanomagnets
• Experimental Clocking of Nanomagnets with Strain for Ultra Low Power Boolean Logic
• Experimental demonstration of complete 180 degree reversal of magnetization in isolated Co-nanomagnets on a PMN-PT substrate with voltage generated strain
• Dark Memory and Accelerator-Rich System Optimization in the Dark Silicon Era
• Domain wall pinning and potential landscapes created by constrictions and protrusions in ferromagnetic nanowires
• Binary switching in a symmetric potential landscape
• Tunable inertia of chiral magnetic domain walls
• Creep of Chiral Domain Walls
• Voltage control of domain walls in magnetic nanowires for energy efficient neuromorphic devices
• Domain-wall motion induced by spin transfer torque delivered by helicity-dependent femtosecond laser