Thermal skyrmion diffusion used in a reshuffler device

Zázvorka, Jakub; Jakobs, Florian; Heinze, Daniel; Keil, Niklas; Kromin, Sascha; Jaiswal, Samridh; Litzius, Kai; Jakob, G.; Virnau, Peter; Pinna, Daniele; Everschor-Sitte, Karin; Rózsa, Levente; Donges, Andreas; Nowak, Ulrich; Kläui, Mathias

doi:10.1038/s41565-019-0436-8

Cited by 296 publications

(315 citation statements)

References 34 publications

Supporting

Mentioning

301

Contrasting

Unclassified

Order By: Relevance

“…The lifetimes of isolated skyrmions in racetrack geometries for Pd/Fe/Ir(111) and Co/Pt(111) systems were investigated in Refs. 22,23 , and different mechanisms were revealed for the collapse of a skyrmion inside the track and at the boundary.The diffusive motion of skyrmions at finite temperature has also attracted significant research attention lately [25][26][27] . Previous studies concentrated on diffusion in infinite or extended geometries, but a clarification of the role of the sample shape still seems to be missing in the case where the sys-tem size becomes comparable to that of the skyrmions.…”

mentioning

confidence: 99%

Stochastic dynamics and pattern formation of geometrically confined skyrmions

et al. 2019

Self Cite

View full text Add to dashboard Cite

Ensembles of magnetic skyrmions in confined geometries are shown to exhibit thermally driven motion on two different time scales. The intrinsic fluctuating dynamics (t ∼ 1 ps) is governed by short-range symmetric and antisymmetric exchange interactions, whereas the long-time limit (t 10 ns) is determined by the coaction of skyrmion-skyrmion-repulsion and the system's geometry. Micromagnetic simulations for realistic island shapes and sizes are performed and analyzed, indicating the special importance of skyrmion dynamics at finite temperatures. We demonstrate how the competition between skyrmion mobility and observation time directly affects the addressability of skyrmionic bits, which is a key challenge on the path of developing skyrmion-based room-temperature applications. The presented quasiparticle Monte Carlo approach offers a computationally efficient description of the diffusive motion of skyrmion ensembles in confined geometries, like racetrack memory setups.Magnetic skyrmions 1-3 are quasiparticles which are considered as possible carriers of information for future storage devices. Their specific chirality is determined by the antisymmetric Dzyaloshinskii-Moriya exchange interaction (DMI) 4,5 . The DMI can be induced by a broken inversion symmetry in a crystal itself (e.g. MnSi) 2 or by interfacing a heavy metal layer (e.g. Pt, W, Ir) with a ferromagnetic material (e.g. Fe, Co) 6,7 .Conceptually the utilization of these topologically nontrivial 8 quasiparticles in so-called racetrack setups is of great interest 9-11 : Skyrmions can be manipulated (written and deleted) 12,13 and addressed individually 14-16 on a magnetic stripe, allowing a memory device extension from a pure surface density into the third dimension by pushing the quasiparticle-hole-train back and forth, e.g. by applying electrical currents 17,18 . The low threshold driving current 19 along with the small size and high stability of the skyrmions are key features of this concept.To connect experimental and theoretical model systems with technological applications, investigating the influence of finite temperatures is of crucial importance. The bits on a racetrack-based memory device need to fulfill two main features, stability against external perturbations and addressability. Both are affected by thermal fluctuations, as shown below.The stability of skyrmions was examined in several publications over the last years 20-24 . Rózsa et al. 21 investigated theoretically periodic two-dimensional Pd/Fe double-layers on Ir(111) and determined the phase diagram as a function of external field and temperature, which includes field-polarized, skyrmion lattice, spin spiral, fluctuation-disordered and paramagnetic regions. Skyrmion lifetimes in the fluctuationdisordered regime were calculated. The lifetimes of isolated skyrmions in racetrack geometries for Pd/Fe/Ir(111) and Co/Pt(111) systems were investigated in Refs. 22,23 , and different mechanisms were revealed for the collapse of a skyrmion inside the track and at the boundary.The diffusive motion...

show abstract

mentioning

confidence: 99%

Stochastic dynamics and pattern formation of geometrically confined skyrmions

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…Since the first experimental observation, magnetic skyrmions have been extensively studied due to their particle-like nature [14,15] and large potential in advanced electronic and spintronic applications [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. So far, the creation, annihilation and manipulation of magnetic skyrmions have been realized in magnetic multilayers at room temperature [18][19][20][22][23][24][25][26][27][28][29][30], and a lot of skyrmion-based device applications have been proposed [31][32][33][34][35][36][37][38][39][40][41][42] and even demonstrated in roomtemperature experiments [43][44][45].…”

Section: Introductionmentioning

confidence: 99%

Static and dynamic properties of bimerons in a frustrated ferromagnetic monolayer

et al. 2020

View full text Add to dashboard Cite

Magnetic bimeron is a topological counterpart of skyrmions in in-plane magnets, which can be used as spintronic information carrier. We report the static properties of bimerons with different topological structures in a frustrated ferromagnetic monolayer, where the bimeron structure is characterized by the vorticity Qv and helicity η. It is found that the bimeron energy increases with Qv, and the energy of an isolated bimeron with Qv = ±1 depends on η. We also report the dynamics of frustrated bimerons driven by the spin-orbit torques, which depend on the strength of the damping-like and field-like torques. We find that the isolated bimeron with Qv = ±1 can be driven into linear or elliptical motion when the spin polarization is perpendicular to the easy axis. We numerically reveal the damping dependence of the bimeron Hall angle driven by the damping-like torque. Besides, the isolated bimeron with Qv = ±1 can be driven into rotation by the damping-like torque when the spin polarization is parallel to the easy axis. The rotation frequency is proportional to the driving current density. In addition, we numerically demonstrate the possibility of creating a bimeron state with a higher or lower topological charge by the current-driven collision and merging of bimeron states with different Qv. Our results could be useful for understanding the bimeron physics in frustrated magnets.

show abstract

“…The reservoir computing was realized via a two-terminal device with nonlinear voltage characteristics originating from magnetoresistive effects. Most recently in 2019, Zázvorka et al experimentally demonstrated a thermal skyrmion diffusion-based signal reshuffling device[88], which shows the possibility of using skyrmions for future probabilistic computing device.…”

mentioning

confidence: 99%

Skyrmion-electronics: writing, deleting, reading and processing magnetic skyrmions toward spintronic applications

Zhang¹,

Zhou²,

Song³

et al. 2020

J. Phys.: Condens. Matter

389

302

View full text Add to dashboard Cite

The field of skyrmionics has been actively investigated across a wide range of topics during the last decade. In this topical review, we review and discuss key results and findings in skyrmionics since the first experimental observation of magnetic skyrmions in 2009. We particularly focus on the theoretical, computational and experimental findings and advances that are directly relevant to the spintronic applications based on magnetic skyrmions, i.e. their writing, deleting, reading and processing driven by magnetic field, electric current and thermal energy. We then review several potential applications including information storage, logic computing gates and non-conventional devices such as neuromorphic computing devices. Finally, we discuss possible future research directions on magnetic skyrmions, which also cover rich topics on other topological textures such as antiskyrmions and bimerons in antiferromagnets and frustrated magnets.

show abstract

Thermal skyrmion diffusion used in a reshuffler device

Cited by 296 publications

References 34 publications

Stochastic dynamics and pattern formation of geometrically confined skyrmions

Stochastic dynamics and pattern formation of geometrically confined skyrmions

Static and dynamic properties of bimerons in a frustrated ferromagnetic monolayer

Skyrmion-electronics: writing, deleting, reading and processing magnetic skyrmions toward spintronic applications

Contact Info

Product

Resources

About