Antiferromagnetic skyrmion repulsion based artificial neuron device

Abstract

Magnetic skyrmions are potential candidates for neuromorphic computing due to their inherent topologically stable particle-like behavior, low driving current density, and nanoscale size. Antiferromagnetic skyrmions are favored as they can be driven parallel to in-plane electrical currents as opposed to ferromagnetic skyrmions which exhibit the skyrmion Hall effect and eventually cause their annihilation at the edge of nanotracks. In this paper, an antiferromagnetic skyrmion based artificial neuron device consisting of a magnetic anisotropy barrier on a nanotrack is proposed. It exploits inter-skyrmion repulsion, mimicking the integrate-fire (IF) functionality of a biological neuron. The device threshold represented by the maximum number of skyrmions that can be pinned by the barrier can be tuned based on the particular current density employed on the nanotrack. The corresponding neuron spiking event occurs when a skyrmion overcomes the barrier. By raising the device threshold, lowering the barrier width and height, the operating current density of the device can be decreased to further enhance its energy efficiency. The proposed device paves the way for developing energy-efficient neuromorphic computing in antiferromagnetic spintronics.

Single-bit full adder and logic gate based on synthetic antiferromagnetic bilayer skyrmions

“…The adders and logic gate operation are demonstrated using micromagnetic simulations performed on the GPU-accelerated open-source micromagnetic simulator software package MuMax3 [41], which have been used in simulating SyAF system as reported in Ref. [42][43][44][45].…”

Antiferromagnetic skyrmion-based high speed diode

“…21,22 However, antiferromagnetic (AFM) skyrmions follow a straight trajectory in the current direction, which is very promising for next-generation spintronic applications. [23][24][25] AFM skyrmions have two sublattices, coupled by the inter-sublattice exchange interaction with no net magnetic moment, thereby vanishing the dipolar elds and completely eliminating the SkHE. AFM skyrmions are thus not only mathematically attractive but also offer major advantages that make them viable alternatives to FM skyrmions.…”

Room temperature ferromagnetic skyrmion-based artificial neuron device

“…But, the induced Magnus force deflects the FM skyrmion from the straight path and this effect is commonly known as skyrmion hall effect (SkHE), this can lead to annihilation of the skyrmion [12][13]. This is a serious issue where the straight motion of skyrmions are necessary [14][15]. The SkHE can be eliminated by various means such as manipulation of synthetic antiferromagnetic (SAF) skyrmion in coupled bilayer-ferromagnetic [16].…”