Biskyrmion-based artificial neuron with refractory period

TL;DR

This paper introduces a biskyrmion-based artificial neuron that mimics biological neuronal behaviors, including refractory periods, by utilizing spin-orbit torques to split and reform skyrmions, enabling more realistic neural dynamics.

Contribution

The study demonstrates a novel biskyrmion-based neuron device that incorporates refractory periods, enhancing the biological realism of skyrmion-based neuromorphic systems.

Findings

The device can split a biskyrmion into two subskyrmions under spin-orbit torques.

Subskyrmions move towards a detector and then automatically return, resetting the neuron.

The neuron exhibits leak, integrate, fire, and refractory behaviors more accurately than existing devices.

Abstract

Magnetic skyrmions are nanoscale magnetic whirls that are highly stable and can be moved by currents which has led to the prediction of a skyrmion-based artificial neuron device with leak-integrate-fire functionality. However, so far, these devices lack a refractory process, estimated to be crucial for neuronal dynamics. Here we demonstrate that a biskyrmion-based artificial neuron overcomes this insufficiency. When driven by spin-orbit torques, a single biskyrmion splits into two subskyrmions that move towards a designated location and can be detected electrically, resembling the excitation process of a neuron that fires ultimately. The attractive interaction of the two skyrmions leads to a unique trajectory: Once they reach the detector area, they automatically return to the center to reform the biskyrmion but on a different path. During this reset period, the neuron cannot fire again. Our suggested device resembles a biological neuron with the leak, integrate, fire and refractory characteristics better than all existing artificial devices so far.