Skyrmion pinning energetics in thin film systems

Gruber, Raphael; Zázvorka, Jakub; Brems, Maarten A.; Rodrigues, Davi R.; Dohi, Takaaki; Kerber, Nico; Seng, Boris; Vafaee, Mehran; Everschor-Sitte, Karin; Virnau, Peter; Kläui, Mathias

doi:10.1038/s41467-022-30743-4

Cited by 30 publications

(30 citation statements)

References 71 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Wan et al show that the exchange and fourth-order magneto-crystalline anisotropies can deform a skyrmion lattice and further induce pinning effects to rotate the skyrmion lattice. These findings complement and deepen our understanding on the pinning effects of skyrmions [5][6][7][8].…”

supporting

confidence: 68%

Editorial: Generation, detection and manipulation of skyrmions in magnetic nanostructures

2022

View full text Add to dashboard Cite

Editorial on the Research Topic Generation, Detection and Manipulation of Skyrmions in Magnetic NanostructuresWith the rapid accumulation of data in science, technology, and social activity in the development of modern society, it is becoming increasingly urgent and important to find efficient and effective methods to store and process information with low power consumption. The skyrmion, a curling field configuration, was originally proposed by nuclear physicist Skyrme [1] and it was recently realized in a wide class of magnetic materials with chiral exchange interactions [2][3][4]. Due to their compact shape and small size down to a few nanometers, good thermal stability, and low driven current density, magnetic skyrmions have become promising building blocks for high-density storage and fast information processing applications. In a dozen years, this field dubbed as skyrmionics has attracted significant attention for exploring fundamental physics as well as for practical applications.This research topic entitled "Generation, Detection, and Manipulation of Skyrmions in Magnetic Nanostructures" aims to address the recent developments in the field of skyrmionics. Particularly, the featured topics include the interplay of skyrmions and spin waves, pinning effects of disorder and defects on skyrmion motion, and the design of spintronic devices with information encoded in skyrmions and other magnetic solitons.Two articles present the interplay of spin waves and magnetic skyrmions. Guan et al. show that an antiferromagnetic skyrmion driven by double circularly-polarized spin waves could move along the intersection of the two microwave sources. Here the skyrmion Hall effect is strongly suppressed because the effective transverse forces acting on the skyrmions generated by the left-handed and right-handed spin waves cancel each other. This theoretical proposal may help to guide skyrmion motion in a desirable trajectory. Yao et al. considered skyrmion generation by spin waves reflected from a curved surface. Usually, spin-wave energy is too small to overcome the barrier between a skyrmion and a ferromagnetic state. Here the authors carefully design a parabolic film edge such that the intensity of spin waves totally reflected from the edge is

show abstract

supporting

confidence: 68%

Editorial: Generation, detection and manipulation of skyrmions in magnetic nanostructures

2022

View full text Add to dashboard Cite

show abstract

“…Figure 1 in the supplementary is the heatmap of the probability of a position for a single skyrmion in the device. One can see that the likelihood at certain positions is increased, indicating the existence of pinning sites 43 , on which it is energetically favorable for the skyrmion to stay. Thermal activation leads to motion around said sites.…”

Section: Methodsmentioning

confidence: 99%

Brownian reservoir computing realized using geometrically confined skyrmion dynamics

et al. 2022

Self Cite

View full text Add to dashboard Cite

Reservoir computing (RC) has been considered as one of the key computational principles beyond von-Neumann computing. Magnetic skyrmions, topological particle-like spin textures in magnetic films are particularly promising for implementing RC, since they respond strongly nonlinearly to external stimuli and feature inherent multiscale dynamics. However, despite several theoretical proposals that exist for skyrmion reservoir computing, experimental realizations have been elusive until now. Here, we propose and experimentally demonstrate a conceptually new approach to skyrmion RC that leverages the thermally activated diffusive motion of skyrmions. By confining the electrically gated and thermal skyrmion motion, we find that already a single skyrmion in a confined geometry suffices to realize nonlinearly separable functions, which we demonstrate for the XOR gate along with all other Boolean logic gate operations. Besides this universality, the reservoir computing concept ensures low training costs and ultra-low power operation with current densities orders of magnitude smaller than those used in existing spintronic reservoir computing demonstrations. Our proposed concept is robust against device imperfections and can be readily extended by linking multiple confined geometries and/or by including more skyrmions in the reservoir, suggesting high potential for scalable and low-energy reservoir computing.

show abstract

“…This leads to inhomogeneities in our system that favour certain regions of the film to accommodate skyrmions. Effective pinning of skyrmions [26] is induced by the grains and consequently, certain arrangements of skyrmions become meta-stable states to which the system can relax following transitory excitationsa feature that ensures the echo state property in such a reservoir. More details on the reservoir can be found in the methods section.…”

Section: Multi-contact Skyrmion Reservoirmentioning

confidence: 99%