Magnetic Skyrmion as a Nonlinear Resistive Element: A Potential Building Block for Reservoir Computing

Abstract

Inspired by the human brain, there is a strong effort to find alternative models of information processing capable of imitating the high energy efficiency of neuromorphic information processing. One possible realization of cognitive computing are reservoir computing networks. These networks are built out of non-linear resistive elements which are recursively connected. We propose that a skyrmion network embedded in frustrated magnetic films may provide a suitable physical implementation for reservoir computing applications.The significant key ingredient of such a network is a two-terminal device with non-linear voltage characteristics originating from single-layer magnetoresistive effects, like the anisotropic magnetoresistance or the recently discovered non-collinear magnetoresistance. The most basic element for a reservoir computing network built from "skyrmion fabrics" is a single skyrmion embedded in a ferromagnetic ribbon. In order to pave the way towards reservoir computing systems based on skyrmion fabrics, here we simulate and analyze i) the current flow through a single magnetic skyrmion due to the anisotropic magneto-resistive effect and ii) the combined physics of local pinning and the anisotropic magneto-resistive effect. 1 arXiv:1702.04298v2 [cond-mat.dis-nn]

Magnetic skyrmion interactions in the micromagnetic framework

“…Their small size and unusual dynamics allow for their utilization in conventional computers, which has prompted a wide study of skyrmionic re-implementations of arithmetic logic units and memory storage devices [5,6]. Additionally, recent studies suggest that skyrmions could find use in exotic devices such as stochastic and reservoir computers [7,8].…”

Skyrmion dynamics and topological sorting on periodic obstacle arrays

“…Skyrmions are readily set into motion via the application of an external current [36,[39][40][41][42], and the resulting velocity-force relations show a pinned to sliding transition that can be observed in transport experiments by measuring changes in the topological Hall effect [39,43] or performing direct imaging of the skyrmion motion [37,40,44]. It is also possible to examine skyrmion dynamics using neutron scattering [45], x-ray diffraction [46], and changes in the noise fluctuations as a function of drive [47,48].Due to their stability, size scale, and manipulability, skyrmions are very promising candidates for a variety of applications including memory, logic devices, and alternative computing architectures [49,50]. The capability to precisely control the direction, traversal distance, and reversibility of skyrmion motion could open up new ways to create such devices, and there are already a number of proposals for controlling skyrmion motion using structured substrates such as race tracks [49,51,52], periodic modulations [53], or specially designed pinning structures [54][55][56][57][58].…”

“…Due to their stability, size scale, and manipulability, skyrmions are very promising candidates for a variety of applications including memory, logic devices, and alternative computing architectures [49,50]. The capability to precisely control the direction, traversal distance, and reversibility of skyrmion motion could open up new ways to create such devices, and there are already a number of proposals for controlling skyrmion motion using structured substrates such as race tracks [49,51,52], periodic modulations [53], or specially designed pinning structures [54][55][56][57][58].…”

Quantum control of topological defects in magnetic systems

“…2,3 Magnetic skyrmions (vortex-like topological spin structures) 4 have defined the field of skyrmionics where every bit of information is represented by the presence or absence of a single skyrmion 2,5,6 . Recent proposals have exploited their miniature size and high mobility for skyrmion-based logic gates 7 , racetrack memories 8 , high-density non-volatile memory 9 , energy-efficient artificial synaptic devices in neuromorphic computing 10 as well as reservoir computing platform 11 . More recently, storage and processing of digital information in magnetic domain walls and their potential uses for logic operations have been discussed.…”