Undermind Research Topic: I want to find theoretical and simulation studies on the formation of skyrmions in materials with varying geometrical parameters such as size and shape of isolated nanostructures.

Research topic

I want to find theoretical and simulation studies on the formation of skyrmions in materials with varying geometrical parameters such as size and shape of isolated nanostructures.

Report

This literature search identified several theoretical and simulation studies that examine the formation of skyrmions with varying geometrical parameters in nanostructures, including size and shape, significantly aiding in understanding the influence of geometrical confinement on skyrmion stability and behavior [1, 5, 6, 7].

Details:

Geometrical Confinement:
- Nanoscale Skyrmion Bubbles: [1] examines the width and thickness of nanostripes and how these parameters influence skyrmion bubbles through dipole-dipole interactions, confirming findings with theoretical simulations.
- Polygonal Nanostructures: [5] uses simulations to explore skyrmion formation in FeGe thin films with non-cylindrical geometries like squares and triangles, illustrating stable skyrmions at 10 nm thickness without applied magnetic field.
- Nanodots: [6] investigates the role of Dzyaloshinskii–Moriya interaction (DMI) and uniaxial anisotropy through micromagnetic simulations, showing that shape and size significantly affect skyrmion formation and stability.

Shape and Size Variability:
- Circular vs. Polygonal Structures: [7] focuses on skyrmions in circular nanodots, emphasizing edge effects and DMI parameters' influence on skyrmion isolation and confinement.
- Hybrid Multilayer Nanodots: [4] illustrates zero-field stabilization of small-sized skyrmions (down to 50 nm) in hybrid multilayer nanodots, modulated by CoB thickness and dot sizes.
- Helimagnetic Nanostructures: [8] demonstrates bistable skyrmionic states in confined helimagnetic nanostructures using 3D micromagnetic simulations, highlighting the impact of shape anisotropy influenced by the DMI.
External Influences and Novel Techniques:
- Finsler Geometry Modeling: [2] employs Finsler geometry and Monte Carlo simulations to study skyrmions in nanodots, showing how geometrical confinement stabilizes skyrmions with specific diameter constraints.
- Field Effects: [14] explores the impact of magnetostatic fields generated by magnetic tips on skyrmion stability in nanodisks, showing how these fields can nucleate and control skyrmions' size and polarity.

Conclusion: The identified studies comprehensively address the formation and stability of skyrmions in various geometrical confinements, demonstrating that nanostructure size and shape are crucial in tailoring skyrmion properties. These findings provide foundational insights for the practical application of skyrmions in spintronic devices and memory storage technologies.

References

Last 5 years

Last 2 years

> 1 citation per year

> 5 citations per year

Topic Match

Cit./Year

Year

Paper

Paper Relevance Summary

95.4%

7.2

2019

[1] Manipulating the Topology of Nanoscale Skyrmion Bubbles by Spatially Geometric Confinement. Z. Hou, ..., and Wenhong Wang ACS nano 2019 - 43 citations - Show abstract - Cite - PDF 95.4% topic match

Provides theoretical simulations on skyrmion bubbles influenced by geometrical confinement. Analyzes the impact of nanostripe width and thickness on skyrmion spin textures. Focuses on dipole-dipole interaction and implications for racetrack memory applications.

95.1%

0.8

2023

[2] Finsler Geometry Modeling and Monte Carlo Study on Geometrically Confined Skyrmions in Nanodots G. Diguet, ..., and H. Diep Journal Not Provided 2023 - 1 citations - Show abstract - Cite - PDF 95.1% topic match

Provides a theoretical and simulation study on skyrmions in nanodots. Utilizes Finsler geometry modeling and Monte Carlo simulations to study stability and morphology of confined skyrmions. Focuses on confinement effects related to nanodot diameter and strain in absence of magnetic anisotropy and mechanical stress.

94.8%

5.2

2017

[3] Geometrically Tailored Skyrmions at Zero Magnetic Field in Multilayered Nanostructures P. Ho, ..., and C. Panagopoulos Physical Review Applied 2017 - 38 citations - Show abstract - Cite - PDF 94.8% topic match

Shows zero-field stabilization of sub-100-nm Neel-textured skyrmions. Demonstrates skyrmion size and stability variations using dot size and magnetic interactions in Ir/Fe(x)/Co(y)/Pt nanodots. Highlights the interaction between magnetic parameters and geometric confinement for tailoring skyrmion properties in devices.

94.6%

0.0

2023

[4] Stability and Character of Zero Field Skyrmionic States in Hybrid Magnetic Multilayer Nanodots Alexander Kang-Jun, ..., and Anjan Soumyanarayanan Journal Not Provided 2023 - 0 citations - Show abstract - Cite - PDF 94.6% topic match

Provides theoretical and simulation study on skyrmion stability in nanodots. Shows zero-field and target skyrmions in hybrid multilayer nanodots with varied CoB thickness and dot sizes. Focuses on the formation and manipulation of skyrmions in specific geometrical parameters, relevant for skyrmionic device applications.

94.6%

4.0

2018

[5] Skyrmion states in thin confined polygonal nanostructures R. Pepper, ..., and H. Fangohr arXiv: Mesoscale and Nanoscale Physics 2018 - 28 citations - Show abstract - Cite - PDF 94.6% topic match

Investigates skyrmion formation in non-cylindrical nanostructures. Uses simulations to show stable skyrmions in triangular and square FeGe nanostructures. Discusses size ($10\,\text{nm}$ thickness) and absence of applied field; relevant for theoretical and simulation aspects.

94.4%

3.5

2018

[6] Size and shape of skyrmions for variable Dzyaloshinskii–Moriya interaction and uniaxial anisotropy Aroop K. Behera, ..., and S. Bedanta Journal of Physics D: Applied Physics 2018 - 23 citations - Show abstract - Cite - PDF 94.4% topic match

Provides micromagnetic simulations of skyrmion formation in varied shapes and anisotropy. Explores the influence of Dzyaloshinskii–Moriya interaction and uniaxial anisotropy in different geometrical nanostructures with perpendicular anisotropy. Highlights the significant role of nanostructure shape and finite size effects on final magnetic states.

94.3%

59.9

2013

[7] Skyrmion confinement in ultrathin film nanostructures in the presence of Dzyaloshinskii-Moriya interaction S. Rohart and A. Thiaville Physical Review B 2013 - 672 citations - Show abstract - Cite - PDF 94.3% topic match

Focus: Shows modification of skyrmion behavior in nanostructures with DMI. Details: Analytical and numerical analysis of skyrmions in circular nanodots, specifically addressing boundary conditions and edge effects. Relevance: Directly examines geometrical confinement and varying DMI parameters, critical for skyrmion stability and isolation in nanostructures.

94.0%

0.1

2016

[8] Skyrmionic states in confined helimagnetic nanostructures M. Beg Journal Not Provided 2016 - 1 citations - Show abstract - Cite Abstract: Magnetic skyrmions have the potential to provide solutions for low-power, high-density data storage and processing. One of the major challenges in developing skyrmion-based devices is the skyrmions' magnetic stability in confined helimagnetic nanostructures. Through a systematic study of equilibrium states, using a full three-dimensional micromagnetic model, we demonstrate that skyrmionic states are the lowest energy states in confined helimagnetic nanostructures at zero external magnetic field and in absence of magnetocrystalline anisotropy. We show that bistable skyrmionic states undergo hysteretic behaviour between two energetically equivalent skyrmionic configurations with different core orientation, even in the absence of both magnetocrystalline and demagnetisation-based shape anisotropies, suggesting the existence of novel Dzyaloshinskii-Moriya-based shape anisotropy. We show that the skyrmionic state core reversal is facilitated by the Bloch point occurrence and propagation. In this work, we also study the dynamic properties (resonance frequencies and corresponding eigenmodes) of these skyrmionic states in confined helimagnetic nanostructures. The eigenvalue method allows us to identify all resonance frequencies and corresponding eigenmodes that can exist in the simulated system. However, using a particular experimentally feasible excitation can excite only a limited set of eigenmodes. Because of that, we perform and report ringdown simulations that resemble the experimental setup using both an in-plane and an out-of-plane excitations. In addition, we report the nonlinear dependence of resonance frequencies on the external magnetic bias field and disk sample diameter and report the possible reversal mode of skyrmionic states. Finally, we show that neglecting the demagnetisation energy contribution or ignoring the magnetisation variation in the out-of-film direction in either static or dynamic simulations is not always justified. 94.0% topic match

Shows skyrmionic states as lowest energy states in confined nanostructures. Utilizes 3D micromagnetic simulations to study skyrmion stability and bistable states in helimagnetic nanostructures without external magnetic fields. Explores skyrmion core reversal and dynamic properties, indicating novel shape anisotropy influenced by Dzyaloshinskii-Moriya interaction.

93.6%

1.0

2022

[9] Micromagnetic Design of Skyrmionic Materials and Chiral Magnetic Configurations in Patterned Nanostructures for Neuromorphic and Qubit Applications R. One, ..., and C. Tiușan Nanomaterials 2022 - 2 citations - Show abstract - Cite - PDF 93.6% topic match

Provides a multi-scale modeling framework addressing skyrmion stability and manipulation in nanostructures. Uses ab-initio and micromagnetic simulations in nanometric disks to explore material parameters affecting skyrmion stability. Identifies magnetic anisotropy, DMI, and saturation magnetization ranges for stabilizing skyrmions, focusing on phase diagrams of nanometric disks.

93.6%

0.8

2013

[10] Finite size effects, stability, hysteretic behaviour, and reversal mechanism of skyrmionic textures in nanostructures M. Beg, ..., and H. Fangohr arXiv: Materials Science 2013 - 9 citations - Show abstract - Cite 93.6% topic match

Shows skyrmion behavior in patterned nanostructures Demonstrates stability, hysteretic behavior, and reversal mechanisms in disk and square shapes Focuses on theoretical aspects; relevant to varying geometry parameters in skyrmion formation studies

92.9%

1.7

2020

[11] Stabilization of Skyrmions in a Nanodisk Without an External Magnetic Field Hang Li, ..., and Zhenxiang Cheng Physical review applied 2020 - 8 citations - Show abstract - Cite - PDF 92.9% topic match

Shows stability of skyrmions in nanodisks without external magnetic fields. Explores how disk size and edge pinning influence skyrmion formation. Numerical simulations indicate the demagnetization field affects Dzyaloshinskii-Moriya interaction, relevant for skyrmion control in geometrically confined nanostructures.

92.8%

2.1

2015

[12] Geometrical and physical conditions for skyrmion stability in a nanowire C. P. Chui, ..., and Yan Zhou AIP Advances 2015 - 20 citations - Show abstract - Cite - PDF 92.8% topic match

Provides theoretical and simulation study on skyrmion stability in nanowires. Investigates geometrical parameters: planar dimensions and thickness, using micromagnetic simulations. Explores material parameters: PMA, DMI, exchange stiffness, temperature effects on skyrmion phase stability.

92.8%

4.3

2019

[13] Evolution of Zero-Field Ferrimagnetic Domains and Skyrmions in Exchange-Coupled Pt/CoGd/Pt Confined Nanostructures: Implications for Antiferromagnetic Devices J. Brandão, ..., and Júlio C. Cezar https://doi.org/10.1021/acsanm.9b01593 2019 - 22 citations - Show abstract - Cite 92.8% topic match

Shows skyrmion formation in nanostructured Pt/CoGd/Pt discs. Demonstrates size-dependent skyrmion formation and stability in isolated nanostructures at zero magnetic field. Relevance: Discusses the influence of disc diameter on skyrmion properties, aligning well with the desired focus on varying geometrical parameters.

92.6%

1.7

2019

[14] Controlling the nucleation and annihilation of skyrmions with magnetostatic interactions N. Vidal-Silva, ..., and D. Altbir Applied Physics Letters 2019 - 10 citations - Show abstract - Cite - PDF 92.6% topic match

Explores control of skyrmions in nanodisks using magnetostatic interactions. Details the nucleation and annihilation processes via magnetic tip interactions through analytical and micromagnetic simulations. Focus is on stability and control in confined geometries, relevant to studies on varying geometrical parameters.

92.5%

0.5

2021

[15] Confinement of Skyrmions in Nanoscale FeGe Device-like Structures A. C. Twitchett-Harrison, ..., and P. Hatton ACS Applied Electronic Materials 2021 - 2 citations - Show abstract - Cite - PDF 92.5% topic match

Shows effects of confinement on skyrmions in device-like nanostructures. Examines skyrmion behavior in FeGe shapes using Lorentz transmission electron microscopy, with dumbbell and block shapes. Studies magnetic and thermal influences, highlighting edge effects in complex geometries.

92.5%

2.2

2015

[16] Degeneracies and fluctuations of N\'e\`el skyrmions in confined geometries R. Keesman, ..., and R. Duine Physical Review B 2015 - 21 citations - Show abstract - Cite - PDF 92.5% topic match

Provides simulations on skyrmion behavior in confined geometries. Uses Monte Carlo simulations to assess skyrmion robustness at elevated temperatures and finite-size effects. Discusses various skyrmion phases and transitions influenced by confined geometries, mentioning quantum and thermal fluctuations.

92.3%

0.1

2015

[17] Degeneracies and ﬂuctuations of N´eel skyrmions in conﬁned geometries R. Keesman, ..., and R. Duine Journal Not Provided 2015 - 1 citations - Show abstract - Cite 92.3% topic match

Provides theoretical insights via Monte Carlo simulations on skyrmion stability in confined geometries. Demonstrates that confined geometries enhance skyrmion stability against thermal fluctuations and finite-size effects. Focuses on transitions between skyrmion and other magnetic phases, relevant for understanding skyrmion behavior in varied geometrical parameters.

92.0%

9.6

2017

[18] Origin of temperature and field dependence of magnetic skyrmion size in ultrathin nanodots R. Tomasello, ..., and G. Finocchio Physical Review B 2017 - 72 citations - Show abstract - Cite - PDF 92.0% topic match

Shows formation and stability of skyrmions in ultrathin nanodots. Analyzes skyrmion sizes within circular nanodots under varying temperature and magnetic fields. Uses micromagnetic simulations but focuses on circular geometry only, not varying shapes.

91.9%

2.9

2021

[19] Field-Dependent Energy Barriers of Magnetic Néel Skyrmions in Ultrathin Circular Nanodots A. Riveros, ..., and O. Chubykalo-Fesenko Physical Review Applied 2021 - 10 citations - Show abstract - Cite 91.9% topic match

Shows energy barriers and stability of Néel skyrmions in ultrathin circular nanodots. Stabilizes skyrmions with an out-of-plane magnetic field at room temperature. Focuses on circular geometries but does not explore varying geometrical parameters.

91.5%

0.0

2020

[20] Effect of random anisotropy in stabilization of topological chiral textures Gajanan Pradhan and S. Bedanta arXiv: Mesoscale and Nanoscale Physics 2020 - 0 citations - Show abstract - Cite - PDF 91.5% topic match

Provides micromagnetic simulations of skyrmion stabilization influenced by random anisotropy. Shows how varying anisotropy constants affect skyrmion shape and size in a square magnetic nanoelement. Relevant to theoretical studies on skyrmion formation in confined geometries, focused on shape distortions due to local anisotropy variations.

91.0%

0.6

2023

[21] Coarse-graining collective skyrmion dynamics in confined geometries T. Winkler, ..., and M. Kläui Applied Physics Letters 2023 - 1 citations - Show abstract - Cite - PDF 91.0% topic match

Investigates skyrmion dynamics in confined geometries using simulations. Focuses on triangular-shaped confinement with four skyrmions and current-induced dynamics. Relevance includes analyzing commensurability effects and skyrmion-boundary interactions in specific geometry.

90.9%

2.5

2018

[22] Interplay between size and stability of magnetic skyrmions A. S. Varentsova, ..., and P. Bessarab Nanosystems: Physics, Chemistry, Mathematics 2018 - 16 citations - Show abstract - Cite - PDF Abstract: The field of localized, topological spin textures such as magnetic skyrmions [1–3] is currently receiving a lot of attention. The interest in skyrmions is motivated by their unique properties potentially making them perfect information carriers [4–7]. Sensitivity of these spin swirls to pulses of electric current [8–10] benefits the efficient control of information flows and facilitates qualitative decrease in power consumption of data processing devices. The small size of skyrmions could increase data storage density far beyond what state-of-the-art technology offers today. For nanoscale skyrmions, thermal stability becomes an issue as thermal fluctuations can spontaneously destroy skyrmion states and, therefore, corrupt the stored data. Available experimental data on magnetic skyrmions in various materials and material combinations demonstrates inverse relationship between the skyrmion size and skyrmion stability: small skyrmions tend to be less stable compared to large ones [8, 11–21]. For example, roomtemperature skyrmions in a Pt/CoFeB/MgO heterostructure are roughly 100 nm in diameter [18], which is more than an order of magnitude larger than skyrmions observed in a Pd/Fe/Ir(111) system only at low temperatures by means of spin-polarized scanning tunneling microscopy [19, 20]. The question then arises as to how general this relation between skyrmion size and skyrmion stability is and whether it is possible to design an optimal medium where magnetic skyrmions are small enough while being sufficiently stable at ambient conditions. Equilibrium properties of skyrmions such as size and shape have intensively been studied since the very discovery of magnetic skyrmions more than twenty years ago [2–4, 22–26], but quantitative characterization of skyrmion stability has started being addressed rather recently [27–38]. Thermal stability can be quantified by calculating skyrmion lifetime using harmonic transition state theory for spins [39]. The theory predicts an Arrhenius expression for the skyrmion lifetime τ as a function of temperature T , 90.9% topic match

Provides insights on skyrmion size vs. stability. Investigates how skyrmion size influences their stability across different materials and conditions. Relevance: Focus on skyrmion stability and formation but lacks emphasis on varying geometrical parameters.

90.6%

0.0

2024

[23] Stable skyrmions in Co/Ni-based nanopillars with perpendicular magnetization anisotropy Gang Lv, ..., and Yaowen Liu Journal of Physics D: Applied Physics 2024 - 0 citations - Show abstract - Cite 90.6% topic match

90.5%

0.5

2016

[24] Analogue Tuning of Magnetic Skyrmion Properties at Room Temperature in Ir/Fe/Co/Pt Multilayers Anjan Soumyanarayanan, ..., and C. Panagopoulos arXiv: Mesoscale and Nanoscale Physics 2016 - 4 citations - Show abstract - Cite 90.5% topic match

Investigates tunable room-temperature skyrmions in multilayer films. Explores skyrmion properties by varying ferromagnetic layer composition and thickness in Ir/Fe/Co/Pt stacks. Focuses on experimental methods rather than theoretical/simulation studies on geometrical parameter variations. Only marginally relevant.

90.2%

7.4

2016

[25] Minimal radius of magnetic skyrmions: statics and dynamics A. Siemens, ..., and R. Wiesendanger New Journal of Physics 2016 - 66 citations - Show abstract - Cite - PDF 90.2% topic match

Provides a phase diagram for skyrmion size and density. Uses Monte-Carlo and Landau–Lifshitz–Gilbert simulations to study skyrmion stability and dynamics. Focuses on minimal skyrmion size and shape on discrete lattices, rather than varying geometrical nanostructures.

90.1%

1.4

2022

[26] Confinement of Magnetic Skyrmions to Corrals of Artificial Surface Pits with Complex Geometries Takao Matsumoto and N. Shibata Frontiers of Physics 2022 - 4 citations - Show abstract - Cite - PDF 90.1% topic match

Provides direct visualization of skyrmions confined to complex geometries. Shows that skyrmion shape and size are affected by confinement to surface-pit corrals under different field conditions. Highlights potential applications of geometrical confinement techniques for future skyrmion-based devices, but mainly focuses on experimental visualization.

89.3%

2.7

2022

[27] Rectangular and square skyrmion crystals on a centrosymmetric square lattice with easy-axis anisotropy S. Hayami Physical Review B 2022 - 7 citations - Show abstract - Cite - PDF 89.3% topic match

89.0%

2.7

2020

[28] Atomistic Perspective of Long Lifetimes of Small Skyrmions at Room Temperature. M. Hoffmann, ..., and S. Blügel Physical review letters 2020 - 13 citations - Show abstract - Cite - PDF 89.0% topic match

Provides an atomistic perspective on skyrmion stability in 2D and 3D geometries. Shows variation in atomistic exchange, stacking order, and layer number affect skyrmion decay rates. Relevant due to focus on geometrical factors, although specificity to isolated nanostructure shapes/sizes is unclear.

88.9%

0.2

2020

[29] Commensurability governing skyrmion diffusion in confined geometries Chengkun Song, ..., and M. Klaui arXiv: Materials Science 2020 - 1 citations - Show abstract - Cite - PDF 88.9% topic match

88.5%

0.3

2017

[30] Computational simulations of complex chiral magnetic structures D. Cortes Journal Not Provided 2017 - 2 citations - Show abstract - Cite Abstract: Since the last century there has been signiﬁcant progress in the research of novel magnetic materials, which has been stimulated by the development of magnetic based technologies such as information recording. In recent years, advances in imaging and microscopy techniques have allowed the experimental observation of chiral magnetic orderings in a range of materials where Dzyaloshinskii-Moriya interactions (DMI) are present. In particular, a whirling structure known as a magnetic skyrmion has become popular since it can be as small as a few nanometres in size, and its non-trivial topology provides this conﬁguration with an extra stability and particle-like features. It has been demonstrated that these properties make a skyrmion an important candidate for a variety of potential applications, especially for storing information bits. In general, the thermal stability of magnetic structures is an engineering problem that is crucial for any real life application of a magnetic technology. Hence, recently the stability of skyrmions has started to be addressed. In this thesis we investigate, through computer simulations, chiral magnetic structures, with special emphasis on skyrmions, in different materials with DMIs. In addition, we implement a numeric algorithm called the Nudged Elastic Band Method (NEBM) to calculate transition paths and energy barriers between equilibrium states of ferromagnetic systems. The barrier scan be used to estimate the average lifetime of these states. We apply the NEBM to analyse the destruction mechanisms of a skyrmion in a thin ﬁlm and we ﬁnd that the lowest energy barrier is associated to the skyrmion annihilation through the boundary of the sample. Furthermore, we study hexagonally shaped ferromagnetic islands to ﬁnd parameter regions, such as applied ﬁeld or sample size, where different chiral conﬁgurations can be stabilised, combining energy and NEBM calculations. Our results are obtained using computer software developed at our research group in a collaborative manner and we discuss the importance of good coding and data sharing practices for computational based scientiﬁc research. 88.5% topic match

Investigates thermal stability of skyrmions via simulations. The simulations focus on chiral magnetic structures in materials with Dzyaloshinskii-Moriya interactions (DMIs). No specific mention of varying geometrical parameters such as size and shape of isolated nanostructures.

88.4%

1.1

2017

[31] Tailoring magnetic skyrmions by geometric confinement of magnetic structures Steven S.-L. Zhang, ..., and Olle Heinonen Applied Physics Letters 2017 - 8 citations - Show abstract - Cite - PDF 88.4% topic match

Shows skyrmion stabilization by geometrical confinement using a Ginzburg-Landau approach. Skyrmion sizes depend on the exchange length and spatial modulation of uniaxial magnetic anisotropy in thin films. Focuses on centro-symmetric ferromagnets; does not directly address varying shape or isolated nanostructures.

87.6%

0.6

2021

[32] Design Rules for DMI-Stabilised Skyrmions L. Ranno and M. Moro Journal Not Provided 2021 - 2 citations - Show abstract - Cite - PDF 87.6% topic match

87.3%

0.0

2024

[33] Stability and dynamics of magnetic skyrmions in FM/AFM heterostructures R. Cheenikundil, ..., and Danny Thonig Journal Not Provided 2024 - 0 citations - Show abstract - Cite - PDF 87.3% topic match

Provides a model study of skyrmions in FM/AFM heterostructures. Focuses on stability and dynamics using atomistic Monte Carlo and spin dynamics simulations. Does not explicitly address varying geometrical parameters of isolated nanostructures, so partially relevant.

86.9%

0.0

2019

[34] Theoretical calculations of localized magnetic states in ultrathin films Anastasiia S. Varentcova Journal Not Provided 2019 - 0 citations - Show abstract - Cite Abstract: Localized, noncollinear spin textures such as magnetic skyrmions may become the basis for digital technologies of the future. Skyrmions as information bits could qualitatively improve characteristics of electronic devices, such as increased information storage density and low power consumption. Despite considerable success of last decades in the ﬁeld of skyrmions, current studies show how challenging it is to optimize size, stability and control over the skyrmions in order to engineer them towards applications. One particular challenge is to design materials where skyrmions are both small and suﬃciently stable at room temperature. The main goal of the present study is to investigate theoretically the relationship between the size and stability of skyrmions in magnetic monolayers. Phase diagram for an isolated skyrmion is obtained by means of minimum energy path calculations and atomistic spin Hamiltonian. It is demonstrated that the energy barrier protecting the skyrmion from collapse to the ferromagnetic state is not uniquely deﬁned by the skyrmion size, although these two properties as functions of relevant material parameters follow similar trends. Stability of nanoscale skyrmions can be enhanced by a concerted adjustment of material parameters. The proposed parameter transformation conserves the skyrmion size, but does not conserve the skyrmion shape which changes from an arrow-like pattern to a proﬁle that resembles magnetic bubbles. This transformation of the skyrmion shape is accompanied by an increase in the collapse energy barrier and thus enhancement of skyrmion stability. Another aim of the work is to compare results obtained using the atomistic model with the predictions of the continuous magnetization theory, a popular approach to the description of the skyrmionic states. The two models agree quite well regard-ing the skyrmion size and proﬁle. However, attempts to estimate energy barrier within the continuum theory lead to an overestimation of stability for the nanoscale skyrmions. The continuous magnetization model provides systematically better predictions of the collapse energy barrier for larger skyrmions. 86.9% topic match

Investigates the relationship between skyrmion size and stability in magnetic monolayers. Uses minimum energy path calculations and an atomistic spin Hamiltonian to derive a phase diagram for isolated skyrmions. Focuses on material parameter adjustments affecting skyrmion shape and stability, not on varying geometrical parameters of nanostructures.

85.9%

16.9

2016

[35] Tailoring magnetic energies to form dipole skyrmions and skyrmion lattices S. Montoya, ..., and E. Fullerton Physical Review B 2016 - 142 citations - Show abstract - Cite - PDF 85.9% topic match

Provides micromagnetic modeling of skyrmion formation in thin films. Demonstrates the formation and controllability of dipole skyrmion phases under various temperatures and magnetic fields.

84.6%

4.3

2019

[36] Magnetic skyrmions in nanostructures of non-centrosymmetric materials Nitish Mathur, ..., and Song Jin APL Materials 2019 - 22 citations - Show abstract - Cite - PDF 84.6% topic match

82.7%

0.0

2022

[37] Effect of Geometric Confinement on the Stabilization of Skyrmions H. Koibuchi, ..., and H. Diep Journal Not Provided 2022 - 0 citations - Show abstract - Cite - PDF 82.7% topic match

75.9%

0.0

2022

[38] Influence of the anisotropy and the DMI constant on the magnetic skyrmions in elliptical and rectangular-shaped nanomagnets J. Alegre, ..., and B. R. Pujada Journal of Physics: Conference Series 2022 - 0 citations - Show abstract - Cite - PDF 75.9% topic match

75.4%

3.3

2021

[39] Geometrically Constrained Skyrmions S. Pathak and R. Hertel Magnetochemistry 2021 - 13 citations - Show abstract - Cite - PDF 75.4% topic match

70.7%

0.0

2018

[40] Optimization of magnetic thin films for generating stable chiral magnetic structures A. Churikova Journal Not Provided 2018 - 0 citations - Show abstract - Cite Abstract: The field of spintronics, or the use of electron spin for information processing, has revolutionized information storage. The long-term stability, low energy and low current in magnetic devices make them attractive for memory storage, sensors and computing. Their effectiveness is limited by the current, density, and device size, which can be optimized by tuning the magnetic materials properties. In this thesis, we show the effectiveness of ferromagnetic materials for the stability of magnetic "bits" numerically, and provide experimental insight into the engineering of material properties of ferrimagnetic and antiferromagnetic films. Skyrmions are topologically protected chiral spin structures that are highly promising candidates for magnetic bits due to their stability and potential for fast motion. These spin structures can be used to encode O's and l's in racetrack memory devices. Chiral domain walls and skyrmions have been studied in magnetic thin films sandwiched between non-identical non-magnetic materials which have high spin-orbit coupling and Dzyaloshinskii-Moriya interaction (DMI). Parameters such as layer thicknesses and composition can be tuned for optimal skyrmion stability, speed, and size. We use micromagnetic simulations to confirm experimental studies where skyrmions have been annihilated systematically with out-of-plane applied fields in the presence of in-plane fields. We show that in-plane magnetic field deforms the skyrmion and its domain wall, increasing the domain wall size and domain wall energy. This effect has been found to be greater in stray-field stabilized skyrmions with zero DMI. We subsequently image ultrasmall skyrmions (of diameters approaching 10 nm) in ferrimagnetic material with a compensated magnetic moment, using a pump-probe X-ray holography technique. Finally, we develop a recipe for synthetic antiferromagnetic materials with perpendicular magnetic anisotropy that have the potential to host skyrmions and detected with X-ray holography imaging. Thesis Supervisor: Geoffrey S. D. Beach Title: Professor of Materials Science and Engineering 70.7% topic match

68.7%

0.0

2020

[41] Observation of multi-skyrmion objects created by size and density control in Ta/CoFeB/MgO films C. Denker, ..., and J. McCord arXiv: Mesoscale and Nanoscale Physics 2020 - 0 citations - Show abstract - Cite - PDF 68.7% topic match

64.9%

0.2

2019

[42] Crafting magnetic skyrmions at room temperature : size, stability and dynamics in multilayers W. Legrand Journal Not Provided 2019 - 1 citations - Show abstract - Cite Abstract: Magnetic skyrmions are nanoscale two-dimensional windings in the spin configuration of some magnetic materials subject to the Dzyaloshinskii-Moriya antisymmetric exchange interaction. They feature a non-trivial topology and show promise to be the smallest achievable magnetic textures. Very recently, magnetic skyrmions have been successfully stabilised up to room temperature by leveraging on the design of magnetic multilayer systems breaking the vertical inversion symmetry. Following up on this achievement, the main objective of this thesis is the understanding and the control of the various physical properties of skyrmions hosted by such multilayer systems. As a first approach to this objective, an original model allowing to predict the profiles adopted by multilayer skyrmions is described and then employed. This numerical model is very generic, as it exploits only the cylindrical symmetry of multilayer skyrmions, in order to determine the magnetostatic interactions with less effort. This model is further extended in order to approximate the thermal stability of multilayer skyrmions, which is key to their experimental realisation. The next aspect of this thesis consists in the experimental study of the electrical manipulation of multilayer skyrmions, demonstrating three main functionalities that are nucleation by local currents, displacement under spin currents and individual detection by transverse voltage. The third aspect of my thesis is the study of the physical properties influencing the current-induced motion of skyrmions in magnetic multilayers. A pinning behaviour is evidenced experimentally and analysed relying on micromagnetic modelling. One of the important results of this work is also the prediction of hybrid chirality for some multilayer magnetic configurations, which is then demonstrated experimentally using a synchrotron technique. The impact of hybrid chirality on current-induced skyrmion motion is discussed and leads to the optimisation of the multilayer design, resulting in the experimental observation of motion for skyrmions below 50 nm in radius at velocities reaching around 40 m/s. The last part of this thesis aims at leveraging on these theoretical and experimental advances in order to reduce the size of skyrmions at room temperature. After the analysis of the impact of dipolar interactions on skyrmion stability, the engineering of the materials and of the layers periodicity is attempted. I also investigate experimentally the conception of magnetic textures with compensated magnetization in multilayer structures known as synthetic antiferromagnets, and show that they can host antiferromagnetic skyrmions at room temperature. This last result opens up new prospects for achieving room-temperature skyrmions combining size in the single-digit nm range and high mobility, potentially allowing applications towards energy-efficient computation and storage devices with a very dense integration. 64.9% topic match

64.9%

0.8

2019

[43] Computational Search for Ultrasmall and Fast Skyrmions in the Inverse Heusler Family Yunkun Xie, ..., and Avik W. Ghosh IEEE Transactions on Magnetics 2019 - 5 citations - Show abstract - Cite - PDF 64.9% topic match

60.2%

0.0

2021

[44] Confinement of Skyrmions in Nanoscale FeGe Device Structures A. C. Twitchett-Harrison, ..., and P. Hatton Journal Not Provided 2021 - 0 citations - Show abstract - Cite 60.2% topic match

58.4%

2.0

2018

[45] Néel skyrmion stability in ultrathin circular magnetic nanodots K. Guslienko Applied Physics Express 2018 - 13 citations - Show abstract - Cite 58.4% topic match

55.7%

12.6

2018

[46] Direct writing of room temperature and zero field skyrmion lattices by a scanning local magnetic field Senfu Zhang, ..., and Xi-xiang Zhang Applied Physics Letters 2018 - 85 citations - Show abstract - Cite Abstract: Magnetic skyrmions are topologically protected nanoscale spin textures exhibiting fascinating physical behaviors. Recent observations of room temperature skyrmions in sputtered multilayer films are an important step towards their use in ultra-low power devices. Such practical applications prefer skyrmions to be stable at zero magnetic fields and room temperature. Here, we report the creation of skyrmion lattices in Pt/Co/Ta multilayers by a scanning local field using magnetic force microscopy tips. We also show that those newly created skyrmion lattices are stable at both room temperature and zero fields. Lorentz transmission electron microscopy measurements reveal that the skyrmions in our films are of Neel-type. To gain a deeper understanding of the mechanism behind the creation of a skyrmion lattice by the scanning of local fields, we perform micromagnetic simulations and find the experimental results to be in agreement with our simulation data. This study opens another avenue for the creation of skyrmion lattices in thin films.Magnetic skyrmions are topologically protected nanoscale spin textures exhibiting fascinating physical behaviors. Recent observations of room temperature skyrmions in sputtered multilayer films are an important step towards their use in ultra-low power devices. Such practical applications prefer skyrmions to be stable at zero magnetic fields and room temperature. Here, we report the creation of skyrmion lattices in Pt/Co/Ta multilayers by a scanning local field using magnetic force microscopy tips. We also show that those newly created skyrmion lattices are stable at both room temperature and zero fields. Lorentz transmission electron microscopy measurements reveal that the skyrmions in our films are of Neel-type. To gain a deeper understanding of the mechanism behind the creation of a skyrmion lattice by the scanning of local fields, we perform micromagnetic simulations and find the experimental results to be in agreement with our simulation data. This study opens another avenue for the creation of skyrm... 55.7% topic match

47.2%

0.9

2016

[47] Quantum Nucleation of Skyrmions in Magnetic Films by Inhomogeneous Fields S. Díaz and D. Arovas Memorial Volume for Shoucheng Zhang 2016 - 8 citations - Show abstract - Cite - PDF 47.2% topic match

44.6%

1.0

2023

[48] Skyrmion size and density in lattices R. Mansell, ..., and Sebastiaan van Dijken Journal of Applied Physics 2023 - 1 citations - Show abstract - Cite 44.6% topic match

43.3%

0.0

2023

[49] Manipulating Skyrmion Motion on a Nanotrack with Varied Material Parameters and Tilted Spin Currents J. Luo 罗, ..., and G. Zhao 赵 Chinese Physics Letters 2023 - 0 citations - Show abstract - Cite 43.3% topic match

42.1%

0.0

2020

[50] Quantitative behavior study of velocity, radius and topological charge on skyrmion/edge interaction dynamics on Co/Pt nanotrack Isaac Andrade Santece, ..., and P. Coura https://doi.org/10.34019/2674-9688.2020.v3.31402 2020 - 0 citations - Show abstract - Cite Abstract: Skyrmions are considered promising candidates to be the information carriers in the next generation of data storage and logic devices, due to its stability and easy control under the application of an electric current. For future technological applications in spintronic devices, it is important to study the properties behavior of these topological excitations during its movement on magnetic nanotracks, specially because in ferromagnetic materials they suffer a kind of magnus effect which tends to spell the skyrmion through the borders, preventing its transport throughout the nanotrack. We used micromagnetic simulations to study the dynamics of a skyrmion on a magnetic nanotrack induced by a spin polarized electric current. We considered thin magnetic nanotrack made of cobalt and platinum multilayers, whose magnetic state is perpendicular to the track plane and contain a single Néel-type Skyrmion. To describe this magnetic system, we used a Hamiltonian containing exchange, Dzyaloshinskii-Moriya, perpendicular magnetic anisotropy and dipole-dipole interactions. In our study we observed the well-known Skyrmion Hall effect and changes in the structure of the skyrmion when it approaches of the border. This alteration can be measured by determining the radius and the topological charge of the Skyrmion. Our simulation results show that both the radius and the topological charge decrease when it approaches of the border. Our study also demonstrates that the skyrmion-border interaction is repulsive, but there is a minimum distance from the border at which the interaction becomes attractive. If the skyrmion exceeds this critical position yc, it will be attracted and annihilated at the border of the nanotrack. We also performed simulations to obtain the limit value jc of the applied current density that the skyrmion can be transported along of the nanotrack without escaping from the side edge. From a technological point of view for possible applications in spintronic devices, the estimate of jc is of crucial importance. 42.1% topic match

38.3%

6.8

2021

[51] Commensurability between Element Symmetry and the Number of Skyrmions Governing Skyrmion Diffusion in Confined Geometries Chengkun Song, ..., and M. Kläui Advanced Functional Materials 2021 - 26 citations - Show abstract - Cite - PDF 38.3% topic match

31.8%

0.0

2017

[52] Coupled modes of one-dimensional skyrmion lattices in nanostrips Sang-Koog Kim, ..., and Bosung Kim Journal Not Provided 2017 - 0 citations - Show abstract - Cite 31.8% topic match

30.3%

1.5

2022

[53] Densely packed skyrmions stabilized at zero magnetic field by indirect exchange coupling in multilayers F. Ajejas, ..., and V. Cros APL Materials 2022 - 3 citations - Show abstract - Cite - PDF 30.3% topic match

28.1%

0.0

2021

[54] Chiral spin textures in Fe/Gd based multilayer thin films Will Parker, ..., and B. McMorran Microscopy and Microanalysis 2021 - 0 citations - Show abstract - Cite - PDF 28.1% topic match

26.7%

0.2

2020

[55] Interaction between defect and skyrmion in nanodisk Chengkun Song, ..., and Qingfang Liu arXiv: Mesoscale and Nanoscale Physics 2020 - 1 citations - Show abstract - Cite - PDF 26.7% topic match

23.2%

0.0

2024

[56] Effect of Magnetic Anisotropy Constants on Skyrmion Formation in Co/Pt Tamali Mukherjee, ..., and Narayana Murthy Journal Not Provided 2024 - 0 citations - Show abstract - Cite - PDF 23.2% topic match

20.5%

0.0

2021

[57] Average radius of skyrmions in the skyrmion phase Yu-Jiao Bo, ..., and Ji-Chong Yang Journal Not Provided 2021 - 0 citations - Show abstract - Cite 20.5% topic match

18.6%

2.3

2016

[58] Hysteresis of nanocylinders with Dzyaloshinskii-Moriya interaction R. Carey, ..., and H. Fangohr Applied Physics Letters 2016 - 20 citations - Show abstract - Cite - PDF 18.6% topic match

18.2%

0.0

2021

[59] Skyrmions in Thin Films, Interfaces and Antiferromagnetism R. Rajagopal https://doi.org/10.5772/INTECHOPEN.97636 2021 - 0 citations - Show abstract - Cite 18.2% topic match

17.8%

1.9

2016

[60] Magnetic skyrmion dynamics in thin cylindrical dots Z. Gareeva and K. Guslienko physica status solidi (RRL) – Rapid Research Letters 2016 - 17 citations - Show abstract - Cite 17.8% topic match

16.8%

0.0

2021

[61] Prioritization of the influence of different exchange interactions and uniaxial anisotropy on the generation and morphology of skyrmions Min Xu, ..., and Runshui Li Journal of Physics D: Applied Physics 2021 - 0 citations - Show abstract - Cite 16.8% topic match

14.5%

0.0

2016

[62] Computational Modeling of the Phase Diagram of Magnetic Skyrmions Yifan Zhou Journal Not Provided 2016 - 0 citations - Show abstract - Cite Abstract: Magnetic skyrmions are vortex-like spin structures that appear in magnetic materials with Dzyaloshinskii-Moriya(DM) interactions and exchange interactions. Their small size and inherent stability suggest the potential application in magnetic memory systems. A well-defined phase diagram of skyrmions is important for investigating their stability. This is a complicated task due to the topological nature of magnetic skyrmions, whose phase transitions are not obviously illustrated by general parameters such as total energy and magnetization. In this thesis, we have developed a methodology in determining the phase diagram of the skyrmion lattice model by performing the atomistic spin simulation. We investigate the spin states of the lattice in the magnetic fields at zero temperature first, then apply finite temperatures in studying the phase transition between the skyrmion state and other states. At 0 K we find five spin states in varying magnetic fields. In the skyrmion state, the ratio between DM interaction and exchange interaction, together with the magnetic anisotropy affect the size and shape of skyrmions. At finite temperatures, the thermal stability of the skyrmion lattice is shown by a contour plot of the skyrmion number as a function of external field and temperature. The loss of lattice symmetry with a growing temperature is demonstrated by the spin configurations of the lattice in the real and reciprocal space. We then characterize the phase transition of the skyrmion state by several specific parameters, such as the specific heat capacity, the static magnetic susceptibility and the skyrmion life time. The parameters show similar critical temperature of the skyrmion state. Specifically, the skyrmion life time of the applied model follows the Arrhenius law as a function of temperature. We also discuss the effect of the femtosecond heat and magnetic pulse on the nucleation of the skyrmion state. 14.5% topic match

13.4%

0.5

2019

[63] Magnetic Skyrmion Spectrum Under Voltage Excitation and its Linear Modulation Xing Chen, ..., and Weisheng Zhao Physical Review Applied 2019 - 3 citations - Show abstract - Cite - PDF 13.4% topic match

13.2%

4.2

2019

[64] Formation of Néel-type skyrmions in an antidot lattice with perpendicular magnetic anisotropy Susmita Saha, ..., and L. Heyderman Physical Review B 2019 - 22 citations - Show abstract - Cite - PDF 13.2% topic match

12.5%

0.5

2019

[65] Skyrmions in anisotropic magnetic fields: strain and defect driven dynamics R. Brearton, ..., and T. Hesjedal MRS Advances 2019 - 3 citations - Show abstract - Cite - PDF 12.5% topic match

12.5%

4.2

2021

[66] Investigation of self-nucleated skyrmion states in the ferromagnetic/nonmagnetic multilayer dot I. Vetrova, ..., and M. Mruczkiewicz Applied Physics Letters 2021 - 15 citations - Show abstract - Cite 12.5% topic match

10.0%

0.0

2017

[67] Magnetic skyrmion research using virtual simulation environments Mark L. Vousden Journal Not Provided 2017 - 0 citations - Show abstract - Cite Abstract: Magnetic skyrmions are particle-like structures in the magnetic moment field of a helimagnetic material. Since skyrmions are of the order of nanometres in size, they are a promising replacement for the larger magnetic domain structures proposed for racetrack memory devices. Skyrmions also motivate the design of small logic gate devices. However, skyrmions are only stable in limited regions of the parameter space defined by the strength of an external magnetic field and the properties of the material. To model the behaviour of skyrmions and the magnetic moment field in a real sample, this thesis contains multiple numerical investigations using the micromagnetic model. Finite-element and finite-difference approaches are used to solve different problems. Due to the complexity of micromagnetic modelling, a software platform is implemented to perform simulations within virtual machines and containers. This novel mechanism has been deployed for public use to improve the reproducibility and accessibility of micromagnetic simulations, and is used for all numerical simulations in this thesis. This thesis demonstrates the potential for materials with an easy-plane magnetocrystalline anisotropy to support skyrmions. This investigation augments existing analytical approaches by considering demagnetising and thickness effects to more accurately model a real helimagnetic material. Skyrmions are found to exist in easyplane anisotropy systems, expanding the space of possible materials for skyrmionbased devices. The size of the skyrmion is also found to increase with the strength of the easy-plane anisotropy, which impacts negatively on the storage density of these devices. In addition to investigating the effect of easy-plane anisotropy, the micromagnetic approach is adapted to model arbitrary polycrystalline grain structures. This adaption is used to understand how a polycrystalline grain structure affects the magnetic moment field of a helimagnet. Individual skyrmions are found to be repulsed by grain boundaries, though skyrmions in neighbouring grains attract each other. This finding suggests that an individual skyrmion could be used as the data structure in logic gate devices, where the polycrystalline structure could determine the logic. These two investigations are combined to model a real bulk helimagnetic material with an arbitrary grain structure and easy-plane anisotropy, and to explain a large topological Hall resistivity observation, which is an indicator of skyrmion presence. The thickness of the material gives rise to two additional skyrmionic structures. This means sufficiently thick materials with both easy-plane anisotropy and an irregular grain structure can support skyrmion states. 10.0% topic match

9.7%

0.6

2021

[68] Skyrmion States in Disk Geometry T. Winkler, ..., and M. Kläui Physical Review Applied 2021 - 2 citations - Show abstract - Cite 9.7% topic match

9.5%

0.0

2017

[69] Toward Magnetic Skyrmion Manipulation Diaz Santiago and Sebastián Alejandro Journal Not Provided 2017 - 0 citations - Show abstract - Cite Abstract: Author(s): Diaz Santiago, Sebastian Alejandro | Advisor(s): Arovas, Daniel P | Abstract: Magnetic skyrmions are nanometer-scale spin textures that enjoy topologically-protected stability and exhibit particle-like behavior. Their rich phenomenology has ignited a growing research interest. These features and their novel transport properties have also made them attractive candidates as information carriers in future high-density magnetic-storage and logic devices, as well as integral components of other spintronic applications. Achieving a high degree of control and manipulation of skyrmions is of immense importance to applications and involves understanding fundamental aspects of the dynamics of twisted spin textures with topological charge at the nanoscale. In chapter five, we have considered zero temperature quantum nucleation of a single skyrmion in magnetic ultrathin films with interfacial Dzyaloshinskii-Moriya interaction (DMI). While a uniform field stabilizes the ferromagnet, an opposing local magnetic field, generated by the tip of a local probe, drives the skyrmion nucleation. Using spin path integrals and a collective coordinate approximation, the tunneling rate from the ferromagnetic to the single skyrmion state is computed as a function of the tip's magnetization and height above the sample surface. Based on the relation between DMI coupling and skyrmion helicity, the latter must be included as an extra degree of freedom in chiral magnets with a spatially inhomogeneous DMI. In chapter six, an effective description of skyrmion dynamics for an arbitrary inhomogeneous DMI coupling is obtained. The resulting generalized Thiele's equation is a dynamical system for the center of mass position and helicity of the skyrmion. We fully characterize the effective dynamics of a single skyrmion in a particular case of engineered DMI coupling: half-planes with opposite-sign DMI. In chapter seven, a particle-based model was used to simulate current-driven magnetic skyrmions interacting with random quenched disorder. We show that the Magnus force combined with the random pinning produces an isotropic effective shaking temperature. Spectral analysis of the velocity noise fluctuations can be used to identify dynamical phase transitions and to extract information about the different dynamic phases.In chapter eight, avalanches of flux-driven magnetic skyrmions in systems with random quenched disorder were also simulated using a particle-based model. The distribution of the avalanche sizes and durations, the associated critical exponents, and the average avalanche shape, were studied for different pinning regimes and Magnus force strengths. 9.5% topic match

9.5%

2.2

2023

[70] A spin model for intrinsic antiferromagnetic skyrmions on a triangular lattice Amal Aldarawsheh, ..., and S. Lounis Frontiers of Physics 2023 - 4 citations - Show abstract - Cite - PDF 9.5% topic match

9.0%

2.6

2020

[71] Tuning the properties of zero-field room temperature ferromagnetic skyrmions by interlayer exchange coupling. Roberto Lo Conte, ..., and R. Wiesendanger Nano letters 2020 - 12 citations - Show abstract - Cite - PDF 9.0% topic match

7.5%

0.0

2023

[72] Anisotropy barrier-induced unidirectional motion of spin wave driven skyrmion Shipra Saini, ..., and Brajesh Kumar Kaushik https://doi.org/10.1117/12.2676810 2023 - 0 citations - Show abstract - Cite 7.5% topic match

7.3%

3.1

2020

[73] Temperature and magnetic field dependent behavior of atomic-scale skyrmions in Pd/Fe/Ir(111) nanoislands Philipp Lindner, ..., and R. Wiesendanger Physical Review B 2020 - 14 citations - Show abstract - Cite 7.3% topic match

7.1%

0.0

2016

[74] Spin Dynamics in Cubic Skyrmion Materials Speaker : Marc Janoschek M. Janoschek Journal Not Provided 2016 - 0 citations - Show abstract - Cite 7.1% topic match

6.7%

40.9

2015

[75] Field-dependent size and shape of single magnetic Skyrmions. Niklas Romming, ..., and R. Wiesendanger Physical review letters 2015 - 397 citations - Show abstract - Cite - PDF 6.7% topic match

6.5%

3.6

2016

[76] Skyrmions in square-lattice antiferromagnets R. Keesman, ..., and R. Duine Physical Review B 2016 - 32 citations - Show abstract - Cite - PDF 6.5% topic match

6.0%

0.1

2006

[77] From bubble to Skyrmion: Dynamic transformation mediated by a strong magnetic tip A. Manoogian Journal Not Provided 2006 - 2 citations - Show abstract - Cite Abstract: AbstractSkyrmions in thin metallic ferromagnetic ﬁlms are stable due to competition between the RKKY interaction and uniaxial magneticanisotropy. We study static nonlinear excitations in magnetic ﬁlm in the presence of strong cylindrical magnetic tip of nanometer size. Wemimic the RKKY interaction by the next-nearest-neighbors ferromagnetic and antiferromagnetic exchange interactions. We demonstrateanalytically and numerically dissipative transformation of a bubble created by a strong magnetic tip into a stable Skyrmion.r 2006 Elsevier B.V. All rights reserved. PACS: 75.50.Ss; 75.70.Ak; 75.70.Kw; 75.40.GbKeywords: Skyrmion; RKKY; Magnetic tip 1. IntroductionRecently a signiﬁcant progress has been achieved in thenanofabrication and design of new technologies for veryhigh density storage on hard disks (densities above500Gbit=in 2 ) [1] and magnetoresistive random accessmemory (MRAM). For the further miniaturization of thedata storage and the magnetic memory it is important todecrease the size of nanoelements. Magnetic defects in suchnanoelements storing bits of information can have verysmall size. The small size about 1nm and stability ofSkyrmios may allow to use their two-dimensional (2D)arrays in magnetic storage devices. To the best of ourknowledge a magnetic memory based on Skyrmions wasnot developed yet. There are no analogs of storage of soextremely high density.Skyrmions are strongly localized scale invariant analogsof magnetic bubble domains (MBD) [2]. The axiallysymmetric Skyrmion solution for boson ﬁelds minimizingthe Hamiltonian and describing the structure of nuclearmatter was ﬁrst found by Skyrme [3]. Belavin andPolyakov [4] based on nonlinear s-model have establishedthat Skyrmion is a topologically nontrivial metastableminimum of energy. Since then the properties of Skyrmionsin 2D magnets and thin magnetic ﬁlms have been widelyinvestigated in last few decades [5–9]. Despite of theoreticalefforts the Skyrmions were not observed experimentally inferromagnets. Such an observation remains a greatchallenge since the ferromagnets are the most naturalsystems in which Skyrmions could be expected. In thisarticle we propose a method of their observation andanalyze quantitatively necessary conditions and output.Slow relaxation spin dynamics of Skyrmion was studiedby Abanov and Pokrovsky [7]. They calculated the radiusof the Skyrmion as a function of time. They have foundthat the interaction of the Ruderman–Kittel–Kasuya–Yosida (RKKY) type together with the uniaxial magneticanisotropy can stabilize the Skyrmion. 6.0% topic match

5.6%

4.8

2023

[78] Magnetic skyrmions: Basic properties and potential applications Shengxi Li, ..., and T. Rasing Interdisciplinary Materials 2023 - 9 citations - Show abstract - Cite - PDF 5.6% topic match

5.3%

0.4

2020

[79] Operando control of skyrmion density in a Lorentz transmission electron microscope with current pulses A. Park, ..., and G. Fuchs Journal of Applied Physics 2020 - 2 citations - Show abstract - Cite - PDF 5.3% topic match

4.9%

1.0

2020

[80] Scattering modes of skyrmions in a bilayer system with ferromagnetic coupling S. Vojkovic, ..., and V. Carvalho-Santos Nanotechnology 2020 - 4 citations - Show abstract - Cite 4.9% topic match

4.7%

0.9

2022

[81] Mixed-Type Skyrmions in Symmetric Pt/Co/Pt Multilayers at Room Temperature Min He, ..., and Ying Zhang Materials 2022 - 2 citations - Show abstract - Cite - PDF 4.7% topic match

4.3%

4.1

2018

[82] Stable Magnetic Skyrmion States at Room Temperature Confined to Corrals of Artificial Surface Pits Fabricated by a Focused Electron Beam. Takao Matsumoto, ..., and N. Shibata Nano letters 2018 - 28 citations - Show abstract - Cite 4.3% topic match

3.8%

0.0

2024

[83] Optimizing skyrmionium movement and stability via stray magnetic fields in trilayer nanowire constructs. Bin Gong, ..., and Yue Zhang Physical chemistry chemical physics : PCCP 2024 - 0 citations - Show abstract - Cite Abstract: Skyrmioniums, known for their unique transport and regulatory properties, are emerging as potential cornerstones for future data storage systems. However, the stability of skyrmionium movement faces considerable challenges due to the skyrmion Hall effect, which is induced by deformation. In response, our research introduces an innovative solution: we utilized micro-magnetic simulations to create a sandwiched trilayer nanowire structure augmented with a stray magnetic field. This combination effectively guides the skyrmionium within the ferromagnetic (FM) layer. Our empirical investigations reveal that the use of a stray magnetic field not only reduces the size of the skyrmionium but also amplifies its stability. This dual-effect proficiently mitigates the deformation of skyrmionium movement and boosts their thermal stability. We find these positive outcomes are most pronounced at a particular intensity of the stray magnetic field. Importantly, the required stray magnetic field can be generated using a heavy metal (HM1) layer of suitable thickness, rendering the practical application of this approach plausible in real-world experiments. Additionally, we analyze the functioning mechanism based on the Landau-Lifshitz-Gilbert (LLG) equation and energy variation. We also develop a deep spiking neural network (DSNN), which achieves a remarkable recognition accuracy of 97%. This achievement is realized through supervised learning via the spike timing dependent plasticity rule (STDP), considering the nanostructure as an artificial synapse device that corresponds to the electrical properties of the nanostructure. In conclusion, our study provides invaluable insights for the design of innovative information storage devices utilizing skyrmionium technology. By tackling the issues presented by the skyrmion Hall effect, we outline a feasible route for the practical application of this advanced technology. Our research, therefore, serves as a robust platform for continued investigations in this field. 3.8% topic match

3.8%

0.0

2022

[84] In-situ Study of Skyrmions at High Resolution using Differential Phase Contrast Microscopy H. Tan, ..., and C. Boothroyd Microscopy and Microanalysis 2022 - 0 citations - Show abstract - Cite 3.8% topic match

3.7%

2.4

2017

[85] Solid-liquid transition of skyrmions in a two-dimensional chiral magnet Yoshihiko Nishikawa, ..., and W. Krauth Physical Review B 2017 - 17 citations - Show abstract - Cite - PDF 3.7% topic match

3.3%

0.7

2022

[86] Enhanced thermally-activated skyrmion diffusion in synthetic antiferromagnetic systems with tunable effective topological charge T. Dohi, ..., and M. Kläui Journal Not Provided 2022 - 2 citations - Show abstract - Cite 3.3% topic match

3.0%

0.9

2018

[87] Gyrotropic resonance of individual N\'eel skyrmions in Ir/Fe/Co/Pt multilayers B. Satywali, ..., and C. Panagopoulos arXiv: Mesoscale and Nanoscale Physics 2018 - 6 citations - Show abstract - Cite - PDF 3.0% topic match

2.9%

1.2

2018

[88] Magnetic skyrmions for future potential memory and logic applications: Alternative information carriers W. Kang, ..., and Weisheng Zhao 2018 Design, Automation & Test in Europe Conference & Exhibition (DATE) 2018 - 8 citations - Show abstract - Cite 2.9% topic match

2.6%

0.3

2016

[89] Control of Hall angle of Skyrmion driven by electric current Gaobin Liu, ..., and Zhidong Zhang Chinese Physics B 2016 - 3 citations - Show abstract - Cite 2.6% topic match

2.4%

0.0

2021

[90] Magnetic Skyrmions: Recent advances and applications Namita Bindal, ..., and Brajesh Kumar Kaushik IEEE Nanotechnology Magazine 2021 - 0 citations - Show abstract - Cite 2.4% topic match

2.4%

7.3

2017

[91] Stability and lifetime of antiferromagnetic skyrmions P. Bessarab, ..., and O. Tretiakov Physical Review B 2017 - 53 citations - Show abstract - Cite - PDF 2.4% topic match

2.3%

10.4

2021

[92] Statics and dynamics of skyrmions interacting with disorder and nanostructures C. Reichhardt, ..., and M. Milošević Reviews of Modern Physics 2021 - 40 citations - Show abstract - Cite - PDF Abstract: Magnetic skyrmions are topologically stable nanoscale particle-like objects that were discovered in 2009. Since that time, intense research interest has led to the identification of numerous compounds that support skyrmions over a range of conditions spanning cryogenic to room temperatures. Skyrmions can be set into motion under various types of driving, and the combination of their size, stability, and dynamics makes them ideal candidates for numerous applications. Skyrmions represent a new class of system in which the energy scales of the skyrmion-skyrmion interactions, sample disorder, temperature, and drive can compete. A growing body of work indicates that the static and dynamic states of skyrmions can be influenced strongly by pinning or disorder in the sample; thus, an understanding of such effects is essential for the eventual use of skyrmions in applications. In this article we review the current state of knowledge regarding individual skyrmions and skyrmion assemblies interacting with quenched disorder or pinning. We outline the microscopic mechanisms for skyrmion pinning, including the repulsive and attractive interactions that can arise from impurities, grain boundaries, or nanostructures. This is followed by descriptions of depinning phenomena, sliding states over disorder, the effect of pinning on the skyrmion Hall angle, the competition between thermal and pinning effects, the control of skyrmion motion using ordered potential landscapes such as one- or two-dimensional periodic asymmetric substrates, the creation of skyrmion diodes, and skyrmion ratchet effects. We highlight the distinctions arising from internal modes and the strong gyroscopic or Magnus forces that cause the dynamical states of skyrmions to differ from those of other systems with pinning. We also discuss future directions and open questions related to the pinning and dynamics in skyrmion systems. 2.3% topic match

2.1%

0.3

2021

[93] Formation and annihilation of magnetic skyrmions on a square lattice Heisenberg Ferromagnet: the role played by the pure and random anisotropy configurations Y. Yüksel Philosophical Magazine 2021 - 1 citations - Show abstract - Cite 2.1% topic match

2.1%

0.3

2021

[94] Stabilizing Zero-Field Skyrmions at Room-Temperature in Perpendicularly Magnetized Multilayers J. Brandão, ..., and F. Béron Magnetic Skyrmions 2021 - 1 citations - Show abstract - Cite 2.1% topic match

2.0%

0.0

2015

[95] Individual skyrmions in helimagnets J. Zang 2015 IEEE Magnetics Conference (INTERMAG) 2015 - 0 citations - Show abstract - Cite 2.0% topic match

1.6%

0.0

2020

[96] Random bit generators based on skyrmions I. Medlej and G. Finocchio Journal Not Provided 2020 - 0 citations - Show abstract - Cite 1.6% topic match

1.5%

1.0

2022

[97] The 20-nm Skyrmion Generated at Room Temperature by Spin-Orbit Torques J. Liu 刘, ..., and W. Jiang 江 Chinese Physics Letters 2022 - 3 citations - Show abstract - Cite - PDF 1.5% topic match

1.5%

43.4

2012

[98] Universal current-velocity relation of skyrmion motion in chiral magnets J. Iwasaki, ..., and N. Nagaosa Nature Communications 2012 - 540 citations - Show abstract - Cite - PDF 1.5% topic match

1.2%

2.0

2019

[99] Skyrmion instabilities and distorted spiral states in a frustrated chiral magnet Thomas T. J. Mutter, ..., and K. Inoue Physical Review B 2019 - 11 citations - Show abstract - Cite - PDF 1.2% topic match

1.0%

3.6

2020

[100] Magnetic Direct-Write Skyrmion Nanolithography. A. Ognev, ..., and A. Samardak ACS nano 2020 - 15 citations - Show abstract - Cite 1.0% topic match

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