Multilayer Ferromagnetic Spintronic Devices for Neuromorphic Computing Applications

TL;DR

This paper demonstrates a multilayer ferromagnetic spintronic device with multilevel resistance states, suitable for neuromorphic computing, achieving 90% accuracy on MNIST and potential use in cryogenic quantum memory.

Contribution

It presents the first experimental and micromagnetic realization of such a device for neuromorphic applications, with demonstrated neural network performance.

Findings

Device exhibits temperature-dependent multilevel resistance states.

Resistance states evolve with spin-orbit torque in experiments and simulations.

Achieves 90% accuracy on MNIST dataset.

Abstract

Spintronics has gone through substantial progress due to its applications in energy-efficient memory, logic and unconventional computing paradigms. Multilayer ferromagnetic thin films are extensively studied for understanding the domain wall and skyrmion dynamics. However, most of these studies are confined to the materials and domain wall/skyrmion physics. In this paper, we present the experimental and micromagnetic realization of a multilayer ferromagnetic spintronic device for neuromorphic computing applications. The device exhibits multilevel resistance states and the number of resistance states increases with lowering temperature. This is supported by the multilevel magnetization behavior observed in the micromagnetic simulations. Furthermore, the evolution of resistance states with spin-orbit torque is also explored in experiments and simulations. Using the multi-level resistance states of the device, we propose its applications as a synaptic device in hardware neural networks and study the linearity performance of the synaptic devices. The neural network based on these devices is trained and tested on the MNIST dataset using a supervised learning algorithm. The devices at the chip level achieve 90\% accuracy. Thus, proving its applications in neuromorphic computing. Furthermore, we lastly discuss the possible application of the device in cryogenic memory electronics for quantum computers.