Spiking Dynamics in Dual Free Layer Perpendicular Magnetic Tunnel Junctions

TL;DR

This paper demonstrates how voltage-driven magnetization dynamics in dual free layer perpendicular magnetic tunnel junctions can emulate spiking neurons, offering a scalable, energy-efficient hardware platform for neuromorphic computing.

Contribution

It introduces a novel magnetic tunnel junction device that mimics neuron spiking behavior with field-free operation and robustness, advancing neuromorphic hardware design.

Findings

Controlled spiking rate via bias voltage

Field-free and magnetic field robust operation

Low energy per spike (4-16 pJ)

Abstract

Spintronic devices have recently attracted a lot of attention in the field of unconventional computing due to their non-volatility for short and long term memory, non-linear fast response and relatively small footprint. Here we report how voltage driven magnetization dynamics of dual free layer perpendicular magnetic tunnel junctions enable to emulate spiking neurons in hardware. The output spiking rate was controlled by varying the dc bias voltage across the device. The field-free operation of this two terminal device and its robustness against an externally applied magnetic field make it a suitable candidate to mimic neuron response in a dense Neural Network (NN). The small energy consumption of the device (4-16 pJ/spike) and its scalability are important benefits for embedded applications. This compact perpendicular magnetic tunnel junction structure could finally bring spiking neural networks (SNN) to sub-100nm size elements.