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Cai N, Liu Y. Skyrmions Subtractor Based on Dzyaloshinskii-Moriya Interaction Gate. J Phys Chem Lett 2024; 15:7775-7781. [PMID: 39047264 DOI: 10.1021/acs.jpclett.4c01542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2024]
Abstract
Skyrmions are increasingly favored in developing various spintronic devices as efficient information carriers. The proposed voltage-controlled Dzyaloshinskii-Moriya interaction (VCDM) offers an additional means to manipulate the movement of skyrmions. In this study, we investigated how the skyrmions behave when passing through the VCDM gate in ferromagnetic nanotracks driven by current. Our findings suggest that reducing the strength of the Dzyaloshinskii-Moriya interaction (DMI) can more effectively block skyrmions, while increasing the DMI strength can more effectively attract them. This indicates that the motion behavior of skyrmions can be controlled by changing the shape of the VCDM gate, thereby demonstrating the effectiveness of VCDM gates in controlling skyrmion motion. Due to the ability of VCDM gates to block skyrmions, we have designed a robust subtractor based on skyrmions. These results provide valuable insights for the development of future skyrmion-based devices using the DMI method.
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Affiliation(s)
- Na Cai
- College of Sciences, Northeastern University, Shenyang 110819, People's Republic of China
| | - Yan Liu
- College of Sciences, Northeastern University, Shenyang 110819, People's Republic of China
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2
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Zhou Y, Li S, Liang X, Zhou Y. Topological Spin Textures: Basic Physics and Devices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2312935. [PMID: 38861696 DOI: 10.1002/adma.202312935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 05/24/2024] [Indexed: 06/13/2024]
Abstract
In the face of escalating modern data storage demands and the constraints of Moore's Law, exploring spintronic solutions, particularly the devices based on magnetic skyrmions, has emerged as a promising frontier in scientific research. Since the first experimental observation of skyrmions, topological spin textures have been extensively studied for their great potential as efficient information carriers in spintronic devices. However, significant challenges have emerged alongside this progress. This review aims to synthesize recent advances in skyrmion research while addressing the major issues encountered in the field. Additionally, current research on promising topological spin structures in addition to skyrmions is summarized. Beyond 2D structures, exploration also extends to 1D magnetic solitons and 3D spin textures. In addition, a diverse array of emerging magnetic materials is introduced, including antiferromagnets and 2D van der Waals magnets, broadening the scope of potential materials hosting topological spin textures. Through a systematic examination of magnetic principles, topological categorization, and the dynamics of spin textures, a comprehensive overview of experimental and theoretical advances in the research of topological magnetism is provided. Finally, both conventional and unconventional applications are summarized based on spin textures proposed thus far. This review provides an outlook on future development in applied spintronics.
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Affiliation(s)
- Yuqing Zhou
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong, 518172, China
| | - Shuang Li
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong, 518172, China
| | - Xue Liang
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong, 518172, China
| | - Yan Zhou
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong, 518172, China
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3
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Saini S, Bindal N, Raj RK, Kaushik BK. A spin wave driven skyrmion-based diode on a T-shaped nanotrack. NANOSCALE 2024. [PMID: 38623868 DOI: 10.1039/d4nr00482e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
The propagation of spin waves is one of the promising ways to design nanoscale spintronic devices. The spin waves can interact with the magnetic skyrmion, a particle-like object that is topologically stabilized by Dzyaloshinskii-Moriya interaction (DMI) in thin film heterostructures. In this work, a spin wave-driven skyrmion-based diode is proposed by employing a T-shaped ferromagnetic nanotrack. The one-way motion of the skyrmion is achieved by exploiting the mid-arm at the center of the nanotrack. This prevents the reverse motion of the skyrmion owing to the skyrmion Hall effect (SkHE) and the absence of a repulsive force from the far edge in the mid-arm region. In order to facilitate the diode functionality of the spin wave-driven skyrmion, the amplitude and frequency of the excitation field should be considered in the ranges 0.07 T ≤ H0 ≤ 0.4 T and 60 GHz ≤ f ≤ 80 GHz, respectively. The micromagnetic interaction energy between the edges and the spin wave-driven skyrmion creates a potential gradient that induces the force which is responsible for the longitudinal motion of the skyrmion. The suggested spin wave driven diode exhibits a processing speed on the order of 100 m s-1 at 60 GHz frequency and 0.4 T amplitude. Hence, this device paves the way for the development of complete non-charge based magnetic devices for various spintronic applications.
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Affiliation(s)
- Shipra Saini
- Department of Electronics and Communication Engineering, Indian Institute of Technology, Roorkee, Uttarakhand, 247667, India.
| | - Namita Bindal
- Department of Electronics and Communication Engineering, Indian Institute of Technology, Roorkee, Uttarakhand, 247667, India.
| | - Ravish Kumar Raj
- Department of Electronics and Communication Engineering, Indian Institute of Technology, Roorkee, Uttarakhand, 247667, India.
| | - Brajesh Kumar Kaushik
- Department of Electronics and Communication Engineering, Indian Institute of Technology, Roorkee, Uttarakhand, 247667, India.
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4
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Yang S, Shen L, Zhao Y, Wu K, Li X, Shen K, Zhang S, Xu X, Åkerman J, Zhou Y. Generation of skyrmions by combining thermal and spin-orbit torque: breaking half skyrmions into skyrmions. NANOSCALE 2024; 16:7068-7075. [PMID: 38450557 DOI: 10.1039/d3nr05803d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/08/2024]
Abstract
Skyrmions, swirling spin textures with topologically protected stability and low critical driven-current density, can be generated from the stripe domain with current pulses, bringing them closer to practical applications in racetrack memory. However, the mechanism of this topological transition from the stripe domain to the skyrmion remains unclear because the transition process occurs at a nanosecond timescale, giving rise to difficulties in observing this process using imaging tools. In this study, we controlled the domain wall - skyrmion transition by combining Joule heating with spin-orbit torque (SOT) and experimentally observed the details of this process, by which we confirmed the mechanism: the spatial variation of the topological charge density induces half skyrmions branching from the stripe domains, and these half skyrmions overcome the surface tension and break away from the stripe domain, resulting in the generation of skyrmions. The details were observed by employing Joule heating to overcome the pinning effect and manipulating the strength of the SOT to induce the branching and breaking of half skyrmions. These findings offer new insights into skyrmion generation and serve as an important step towards the development of highly efficient devices for processing and computing based on skyrmionics.
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Affiliation(s)
- Sheng Yang
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, 518172, China.
| | - Laichuan Shen
- The Center for Advanced Quantum Studies and Department of Physics, Beijing Normal University, Beijing, 100875, China
- Key Laboratory of Multi-scale Spin Physics, Ministry of Education, Beijing Normal University, Beijing, 100875, China
| | - Yuelei Zhao
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, 518172, China.
| | - Kai Wu
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, 518172, China.
| | - Xiaoguang Li
- Center for Advanced Material Diagnostic Technology, College of Engineering Physics, Shenzhen Technology University, Shenzhen, 518118, China
| | - Ka Shen
- The Center for Advanced Quantum Studies and Department of Physics, Beijing Normal University, Beijing, 100875, China
- Key Laboratory of Multi-scale Spin Physics, Ministry of Education, Beijing Normal University, Beijing, 100875, China
| | - Senfu Zhang
- Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou, 730000, China
| | - Xiaohong Xu
- School of Chemistry and Materials Science of Shanxi Normal University & Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of Education, Taiyuan, 030006, China
- Research Institute of Materials Science of Shanxi Normal University & Collaborative Innovation Center for Shanxi Advanced Permanent Magnetic Materials and Technology, Taiyuan, 030006, China
| | - Johan Åkerman
- Department of Physics, University of Gothenburg, Gothenburg, 41296, Sweden
- Science and Innovation in Spintronics Research Institute of Electrical Communication, Tohoku University, Aoba-ku, 980-8577, Japan
| | - Yan Zhou
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, 518172, China.
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5
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Li D, Haldar S, Heinze S. Proposal for All-Electrical Skyrmion Detection in van der Waals Tunnel Junctions. NANO LETTERS 2024; 24:2496-2502. [PMID: 38350134 DOI: 10.1021/acs.nanolett.3c04238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/15/2024]
Abstract
A major challenge for magnetic skyrmions in atomically thin van der Waals (vdW) materials is reliable skyrmion detection. Here, based on rigorous first-principles calculations, we show that all-electrical skyrmion detection is feasible in two-dimensional vdW magnets via scanning tunneling microscopy (STM) and in planar tunnel junctions. We use the nonequilibrium Green's function method for quantum transport in planar junctions, including self-energy due to electrodes and working conditions, going beyond the standard Tersoff-Hamann approximation. We obtain a very large tunneling anisotropic magnetoresistance (TAMR) around the Fermi energy for a graphite/Fe3GeTe2/germanene/graphite vdW tunnel junction. For atomic-scale skyrmions, the noncollinear magnetoresistance (NCMR) reaches giant values. We trace the origin of the NCMR to spin mixing between spin-up and -down states of pz and dz2 character at the surface atoms. Both TAMR and NCMR are drastically enhanced in tunnel junctions with respect to STM geometry due to orbital symmetry matching at the interface.
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Affiliation(s)
- Dongzhe Li
- CEMES, Université de Toulouse, CNRS, 29 rue Jeanne Marvig, F-31055 Toulouse, France
| | - Soumyajyoti Haldar
- Institute of Theoretical Physics and Astrophysics, University of Kiel, Leibnizstrasse 15, 24098 Kiel, Germany
| | - Stefan Heinze
- Institute of Theoretical Physics and Astrophysics, University of Kiel, Leibnizstrasse 15, 24098 Kiel, Germany
- Kiel Nano, Surface and Interface Science (KiNSIS), University of Kiel, 24118 Kiel, Germany
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Bhukta M, Dohi T, Bharadwaj VK, Zarzuela R, Syskaki MA, Foerster M, Niño MA, Sinova J, Frömter R, Kläui M. Homochiral antiferromagnetic merons, antimerons and bimerons realized in synthetic antiferromagnets. Nat Commun 2024; 15:1641. [PMID: 38409221 PMCID: PMC10897388 DOI: 10.1038/s41467-024-45375-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 01/23/2024] [Indexed: 02/28/2024] Open
Abstract
The ever-growing demand for device miniaturization and energy efficiency in data storage and computing technology has prompted a shift towards antiferromagnetic topological spin textures as information carriers. This shift is primarily owing to their negligible stray fields, leading to higher possible device density and potentially ultrafast dynamics. We realize in this work such chiral in-plane topological antiferromagnetic spin textures namely merons, antimerons, and bimerons in synthetic antiferromagnets by concurrently engineering the effective perpendicular magnetic anisotropy, the interlayer exchange coupling, and the magnetic compensation ratio. We demonstrate multimodal vector imaging of the three-dimensional Néel order parameter, revealing the topology of those spin textures and a globally well-defined chirality, which is a crucial requirement for controlled current-induced dynamics. Our analysis reveals that the interplay between interlayer exchange and interlayer magnetic dipolar interactions plays a key role to significantly reduce the critical strength of the Dzyaloshinskii-Moriya interaction required to stabilize topological spin textures, such as antiferromagnetic merons, in synthetic antiferromagnets, making them a promising platform for next-generation spintronics applications.
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Affiliation(s)
- Mona Bhukta
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099, Mainz, Germany
| | - Takaaki Dohi
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099, Mainz, Germany.
- Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba, Sendai, 980-8577, Japan.
| | | | - Ricardo Zarzuela
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099, Mainz, Germany
| | - Maria-Andromachi Syskaki
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099, Mainz, Germany
- Singulus Technologies AG, Hanauer Landstrasse 107, 63796, Kahl am Main, Germany
| | - Michael Foerster
- ALBA Synchrotron Light Facility, 08290, Cerdanyola del Vallés, Barcelona, Spain
| | - Miguel Angel Niño
- ALBA Synchrotron Light Facility, 08290, Cerdanyola del Vallés, Barcelona, Spain
| | - Jairo Sinova
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099, Mainz, Germany
| | - Robert Frömter
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099, Mainz, Germany.
| | - Mathias Kläui
- Institute of Physics, Johannes Gutenberg-University Mainz, 55099, Mainz, Germany.
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7
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Moon A, Li Y, McKeever C, Casas BW, Bravo M, Zheng W, Macy J, Petford-Long AK, McCandless GT, Chan JY, Phatak C, Santos EJG, Balicas L. Writing and Detecting Topological Charges in Exfoliated Fe 5-xGeTe 2. ACS NANO 2024; 18:4216-4228. [PMID: 38262067 DOI: 10.1021/acsnano.3c09234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2024]
Abstract
Fe5-xGeTe2 is a promising two-dimensional (2D) van der Waals (vdW) magnet for practical applications, given its magnetic properties. These include Curie temperatures above room temperature, and topological spin textures─TST (both merons and skyrmions), responsible for a pronounced anomalous Hall effect (AHE) and its topological counterpart (THE), which can be harvested for spintronics. Here, we show that both the AHE and THE can be amplified considerably by just adjusting the thickness of exfoliated Fe5-xGeTe2, with THE becoming observable even in zero magnetic field due to a field-induced unbalance in topological charges. Using a complementary suite of techniques, including electronic transport, Lorentz transmission electron microscopy, and micromagnetic simulations, we reveal the emergence of substantial coercive fields upon exfoliation, which are absent in the bulk, implying thickness-dependent magnetic interactions that affect the TST. We detected a "magic" thickness t ≈ 30 nm where the formation of TST is maximized, inducing large magnitudes for the topological charge density (∼6.45 × 1020 cm-2), and the concomitant anomalous (ρxyA,max ≃22.6 μΩ cm) and topological (ρxyu,T 1≃5 μΩ cm) Hall resistivities at T ≈ 120 K. These values for ρxyA,max and ρxyu,T are higher than those found in magnetic topological insulators and, so far, the largest reported for 2D magnets. The hitherto unobserved THE under zero magnetic field could provide a platform for the writing and electrical detection of TST aiming at energy-efficient devices based on vdW ferromagnets.
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Affiliation(s)
- Alex Moon
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, Florida 32310, United States
- Department of Physics, Florida State University, 77 Chieftan Way, Tallahassee, Florida 32306, United States
| | - Yue Li
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Conor McKeever
- Institute for Condensed Matter and Complex Systems, School of Physics and Astronomy, The University of Edinburgh, Edinburgh EH9 3FD, U.K
| | - Brian W Casas
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, Florida 32310, United States
| | - Moises Bravo
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas 76798, United States
| | - Wenkai Zheng
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, Florida 32310, United States
- Department of Physics, Florida State University, 77 Chieftan Way, Tallahassee, Florida 32306, United States
| | - Juan Macy
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, Florida 32310, United States
- Department of Physics, Florida State University, 77 Chieftan Way, Tallahassee, Florida 32306, United States
| | - Amanda K Petford-Long
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Gregory T McCandless
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas 76798, United States
| | - Julia Y Chan
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas 76798, United States
| | - Charudatta Phatak
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Elton J G Santos
- Institute for Condensed Matter and Complex Systems, School of Physics and Astronomy, The University of Edinburgh, Edinburgh EH9 3FD, U.K
- Higgs Centre for Theoretical Physics, The University of Edinburgh, Edinburgh EH9 3FD, U.K
| | - Luis Balicas
- National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, Florida 32310, United States
- Department of Physics, Florida State University, 77 Chieftan Way, Tallahassee, Florida 32306, United States
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8
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Zhu H, Xiang G, Feng Y, Zhang X. Dynamics of Elliptical Magnetic Skyrmion in Defective Racetrack. NANOMATERIALS (BASEL, SWITZERLAND) 2024; 14:312. [PMID: 38334583 PMCID: PMC10857043 DOI: 10.3390/nano14030312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 02/01/2024] [Accepted: 02/01/2024] [Indexed: 02/10/2024]
Abstract
Recently, it has been reported that the skyrmion Hall effect can be suppressed in an elliptical skyrmion-based device. Given that defects are unavoidable in materials, it is necessary and important to investigate the dynamics of an elliptical skyrmion in a defective racetrack device. In this work, the current-driven dynamics of an elliptical skyrmion in a defective racetrack device are systematically studied using micromagnetic simulations. The system energy analysis reveals that the magnetic parameters of the circular defect play critical roles in determining the type (repulsive or attractive) and the magnitude of the force on the elliptical skyrmion. The simulated trajectories show that the primary motion modes of the elliptical skyrmion in the defective racetrack can be divided into four types, which are dependent on the values of the Dzyaloshinskii-Moriya interaction (DMI) constant Dd, the perpendicular magnetic anisotropy constant Kd, the magnitude of the driving current density J, and the size d of the defect. Further investigation of the motion-mode phases of the skyrmion reveals the synthetic effects of Dd, Kd, J, and d. Finally, the minimum depinning current density J, which linearly depends on the parameters of Dd and Kd, is obtained for a skyrmion completely pinned in the defect. Our findings give insights into the dynamics of an elliptical skyrmion in the presence of a defect with different magnetic parameters in a racetrack device and may be useful for performance enhancement of skyrmion-based racetrack memory devices.
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Affiliation(s)
| | | | | | - Xi Zhang
- College of Physics, Sichuan University, Chengdu 610065, China
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9
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Sara S, Murapaka C, Haldar A. Voltage-controlled magnetic anisotropy gradient-driven skyrmion-based half-adder and full-adder. NANOSCALE 2024; 16:1843-1852. [PMID: 38168698 DOI: 10.1039/d3nr05545k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Spintronic devices have revolutionized the way we process or store information compared to dissipative charge-based electronics. Among various spin-based technologies, skyrmions - topologically protected nano-size spin textures - have emerged as the most promising alternative for future data processing. Here, we have proposed binary adder circuits - central to most digital logic circuits - based on skyrmions. Using micromagnetic simulations, we have demonstrated half-adder and full-adder logic functionalities by precisely driving the skyrmions through voltage-controlled magnetic anisotropy gradient, besides taking advantage of the physical effects such as the skyrmion Hall effect, skyrmion-skyrmion topological repulsion and skyrmion-edge repulsions. The proposed voltage-control-based method of driving the skyrmions is energy efficient compared to the electrical current-driven approach, and it also overcomes the issue of Joule heating. A reliable operation in a wide range of Dzyaloshinskii-Moriya interaction strengths, magnetic anisotropy gradient, and dimensional parameters has been shown, which offers robustness to the device design. The results pave the way for the skyrmion-based computational architecture, which is significant for next-generation non-volatile data processing.
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Affiliation(s)
- Sarwath Sara
- Department of Physics, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, Telangana 502284, India.
| | - Chandrasekhar Murapaka
- Department of Materials Science and Metallurgical Engineering, Indian Institute of Technology Hyderabad, Kandi 502285, Telangana, India
| | - Arabinda Haldar
- Department of Physics, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, Telangana 502284, India.
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10
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Belrhazi H, Fattouhi M, El Hafidi MY, El Hafidi M. Reconfigurable Skyrmion-Based Logic Gates: Versatile Design and Full-Scale Implementation. ACS APPLIED MATERIALS & INTERFACES 2024; 16:3703-3718. [PMID: 38214036 DOI: 10.1021/acsami.3c16542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2024]
Abstract
Herein, we investigate the behavior of skyrmions within a racetrack design incorporating voltage-controlled magnetic anisotropy (VCMA) gates. Our analysis encompassed multiple forces, including spin currents and anisotropy gradients induced by bias voltages. As a result, the efficient control of skyrmion dynamics was achieved across various VCMA gate configurations. Building upon these findings, we propose an efficient approach to reconfigurable skyrmion logic (RSL) in a thin antiferromagnetic (AFM) film through a versatile design. Our RSL harnesses the selective integration of VCMA, spin-polarized currents, and skyrmion-skyrmion (sky-sky) interactions to implement multiple logic gates, including AND, OR, XOR, NOT, NAND, XNOR, and NOR. The design brings a significant advantage with its simplified fabrication process, making the implementation of the RSL practical and accessible for various applications. Furthermore, the RSL enables seamless dynamic switching between logic gates, thereby enhancing its multifunctionality. Additionally, the strategic incorporation of sky-sky interactions and skyrmion-edge repulsion prominently facilitates the realization of complex gates, such as NAND, XNOR, and NOR gates, that typically require intricate design efforts. Hence, this streamlined integration of RSL, coupled with its adaptability to changing computational needs, underscores its potential as a practical solution for implementing high-functionality skyrmion-based logic gates.
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Affiliation(s)
- Hamza Belrhazi
- Condensed Matter Physics Laboratory, Department of Physics, Faculty of Science Ben M'sik, Hassan II University of Casablanca, D. El Harty Av., B.P 7955, 20165 Casablanca, Morocco
| | - Mouad Fattouhi
- Department of Applied Physics, University of Salamanca, 37008 Salamanca, Spain
| | - M Youssef El Hafidi
- Condensed Matter Physics Laboratory, Department of Physics, Faculty of Science Ben M'sik, Hassan II University of Casablanca, D. El Harty Av., B.P 7955, 20165 Casablanca, Morocco
| | - Mohamed El Hafidi
- Condensed Matter Physics Laboratory, Department of Physics, Faculty of Science Ben M'sik, Hassan II University of Casablanca, D. El Harty Av., B.P 7955, 20165 Casablanca, Morocco
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11
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Xu M, Chen X, Guo Y, Wang Y, Qiu D, Du X, Cui Y, Wang X, Xiong J. Reconfigurable Neuromorphic Computing: Materials, Devices, and Integration. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2301063. [PMID: 37285592 DOI: 10.1002/adma.202301063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 05/15/2023] [Indexed: 06/09/2023]
Abstract
Neuromorphic computing has been attracting ever-increasing attention due to superior energy efficiency, with great promise to promote the next wave of artificial general intelligence in the post-Moore era. Current approaches are, however, broadly designed for stationary and unitary assignments, thus encountering reluctant interconnections, power consumption, and data-intensive computing in that domain. Reconfigurable neuromorphic computing, an on-demand paradigm inspired by the inherent programmability of brain, can maximally reallocate finite resources to perform the proliferation of reproducibly brain-inspired functions, highlighting a disruptive framework for bridging the gap between different primitives. Although relevant research has flourished in diverse materials and devices with novel mechanisms and architectures, a precise overview remains blank and urgently desirable. Herein, the recent strides along this pursuit are systematically reviewed from material, device, and integration perspectives. At the material and device level, one comprehensively conclude the dominant mechanisms for reconfigurability, categorized into ion migration, carrier migration, phase transition, spintronics, and photonics. Integration-level developments for reconfigurable neuromorphic computing are also exhibited. Finally, a perspective on the future challenges for reconfigurable neuromorphic computing is discussed, definitely expanding its horizon for scientific communities.
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Affiliation(s)
- Minyi Xu
- State Key Laboratory of Electronic Thin Film and Integrated Devices, School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Xinrui Chen
- State Key Laboratory of Electronic Thin Film and Integrated Devices, School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Yehao Guo
- State Key Laboratory of Electronic Thin Film and Integrated Devices, School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Yang Wang
- State Key Laboratory of Electronic Thin Film and Integrated Devices, School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Dong Qiu
- State Key Laboratory of Electronic Thin Film and Integrated Devices, School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Xinchuan Du
- State Key Laboratory of Electronic Thin Film and Integrated Devices, School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Yi Cui
- State Key Laboratory of Electronic Thin Film and Integrated Devices, School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Xianfu Wang
- State Key Laboratory of Electronic Thin Film and Integrated Devices, School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Jie Xiong
- State Key Laboratory of Electronic Thin Film and Integrated Devices, School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China
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12
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Raj RK, Bindal N, Kaushik BK. Skyrmion motion under temperature gradient and application in logic devices. NANOTECHNOLOGY 2023; 35:075703. [PMID: 38014695 DOI: 10.1088/1361-6528/acfd33] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Accepted: 09/25/2023] [Indexed: 11/29/2023]
Abstract
Under the presence of temperature gradient (TG) on a nanotrack, it is necessary to investigate the skyrmion dynamics in various magnetic systems under the combined effect of forces due to magnonic spin transfer torque(μSTT),thermal STT (τSTT), entropic difference(dS),as well as thermal induced dipolar field (DF). Hence, in this work, the dynamics of skyrmions in ferromagnets (FM), synthetic antiferromagnets (SAF), and antiferromagnets (AFM) have been studied under different TGs and damping constants (αG). It is observed thatαGplays a major role in deciding the direction of skyrmion motion either towards the hotter or colder side in different magnetic structures. Later, FM skyrmion based logic device is proposed that consists of a cross-coupled nanotrack, where the skyrmions on horizontal and vertical nanotrack are controlled by exploiting TG and electrical STT (eSTT), respectively by taking the advantages of thermal induced skyrmion Hall effect (SkHE). The proposed device performs AND and OR logic functionalities simultaneously, when the applied current density is2×1011Am-2.Moreover, the proposed device is also able to exhibit the half adder functionality by tuning the applied current density to3×1011Am-2.The total energy consumption for AND and OR logic operation and half adder are 33.63 fJ and 25.06 fJ, respectively. This paves the way for the development of energy-efficient logic devices with ultra-high storage density.
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Affiliation(s)
- Ravish Kumar Raj
- Department of Electronics and Communication Engineering, Indian Institute of Technology, Roorkee 247667, India
| | - Namita Bindal
- Department of Electronics and Communication Engineering, Indian Institute of Technology, Roorkee 247667, India
| | - Brajesh Kumar Kaushik
- Department of Electronics and Communication Engineering, Indian Institute of Technology, Roorkee 247667, India
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13
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He B, Tomasello R, Luo X, Zhang R, Nie Z, Carpentieri M, Han X, Finocchio G, Yu G. All-Electrical 9-Bit Skyrmion-Based Racetrack Memory Designed with Laser Irradiation. NANO LETTERS 2023; 23:9482-9490. [PMID: 37818857 DOI: 10.1021/acs.nanolett.3c02978] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
Racetrack memories with magnetic skyrmions have recently been proposed as a promising storage technology. To be appealing, several challenges must still be faced for the deterministic generation of skyrmions, their high-fidelity transfer, and accurate reading. Here, we realize the first proof-of-concept of a 9-bit skyrmion racetrack memory with all-electrical controllable functionalities implemented in the same device. The key ingredient is the generation of a tailored nonuniform distribution of magnetic anisotropy via laser irradiation in order to (i) create a well-defined skyrmion nucleation center, (ii) define the memory cells hosting the information coded as the presence/absence of skyrmions, and (iii) improve the signal-to-noise ratio of anomalous Hall resistance measurements. This work introduces a strategy to unify previous findings and predictions for the development of a generation of racetrack memories with robust control of skyrmion nucleation and position, as well as effective skyrmion electrical detection.
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Affiliation(s)
- Bin He
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Riccardo Tomasello
- Department of Electrical and Information Engineering, Politecnico of Bari, Bari 70125, Italy
| | - Xuming Luo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Ran Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Zhuyang Nie
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Mario Carpentieri
- Department of Electrical and Information Engineering, Politecnico of Bari, Bari 70125, Italy
| | - Xiufeng Han
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, People's Republic of China
| | - Giovanni Finocchio
- Department of Mathematical and Computer Sciences, Physical Sciences and Earth Sciences, University of Messina, Messina 98166, Italy
| | - Guoqiang Yu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, People's Republic of China
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14
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Shin J, Seo J, Song S, Kim W, Hyeon DS, Hong J. Non-volatile reconfigurable spin logic functions in a two-channel Hall bar by spin-orbit torque-based magnetic domains and directional read current. Sci Rep 2023; 13:11600. [PMID: 37463993 DOI: 10.1038/s41598-023-38580-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 07/11/2023] [Indexed: 07/20/2023] Open
Abstract
A long-standing goal of CMOS-based logic devices is to meet the needs of key markets, including ultralow-power operation and high operation speed, along with the continuing miniaturization of the architecture. However, despite significant progress in their development, conventional CMOS-based devices still suffer from drawbacks such as introducing large unintended leakage currents and volatile behavior. Thus, reconfigurable logic gates based on magnetic domain (MD) have emerged as a highly promising option because they offer fast operation speeds, nonvolatility, and diverse logic functions in a single-device configuration. Here, we address multiple reconfigurable MD logic gates in a single two-channel Hall bar device by varying the voltage-driven read-current directions and selecting a non-inverting or inverting comparator in W/CoFeB/MgO/Ta stacks. The non-volatile MD switching behavior induced by spin-orbit torque significantly affects our logic gate functions, which are not necessarily synchronized to a single clock. By adapting MD switching by spin-orbit torque and anomalous Hall effect voltage outputs, we identified eight reconfigurable logic gates, including AND, NAND, NOR, OR, INH, Converse INH, Converse IMP, and IMP, in a single device. These experimental findings represent a significant step forward in a wide range of MD-based logic applications in the near future.
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Affiliation(s)
- JeongHun Shin
- Division of Nanoscale Semiconductor Engineering, Hanyang University, Seoul, 133-791, South Korea
| | - Jeongwoo Seo
- Novel Functional Materials and Device Laboratory, Department of Physics, Research Institute of Natural Science, Hanyang University, Seoul, 133-791, Korea
| | - Saegyoung Song
- Novel Functional Materials and Device Laboratory, Department of Physics, Research Institute of Natural Science, Hanyang University, Seoul, 133-791, Korea
| | - WooJong Kim
- Division of Nanoscale Semiconductor Engineering, Hanyang University, Seoul, 133-791, South Korea
| | - Da Seul Hyeon
- Novel Functional Materials and Device Laboratory, Department of Physics, Research Institute of Natural Science, Hanyang University, Seoul, 133-791, Korea
| | - JinPyo Hong
- Division of Nanoscale Semiconductor Engineering, Hanyang University, Seoul, 133-791, South Korea.
- Novel Functional Materials and Device Laboratory, Department of Physics, Research Institute of Natural Science, Hanyang University, Seoul, 133-791, Korea.
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15
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Casas BW, Li Y, Moon A, Xin Y, McKeever C, Macy J, Petford-Long AK, Phatak CM, Santos EJG, Choi ES, Balicas L. Coexistence of Merons with Skyrmions in the Centrosymmetric Van Der Waals Ferromagnet Fe 5- x GeTe 2. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2212087. [PMID: 36780298 DOI: 10.1002/adma.202212087] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Revised: 02/02/2023] [Indexed: 05/17/2023]
Abstract
Fe5- x GeTe2 is a centrosymmetric, layered van der Waals (vdW) ferromagnet that displays Curie temperatures Tc (270-330 K) that are within the useful range for spintronic applications. However, little is known about the interplay between its topological spin textures (e.g., merons, skyrmions) with technologically relevant transport properties such as the topological Hall effect (THE) or topological thermal transport. Here, via high-resolution Lorentz transmission electron microscopy, it is shown that merons and anti-meron pairs coexist with Néel skyrmions in Fe5- x GeTe2 over a wide range of temperatures and probe their effects on thermal and electrical transport. A THE is detected, even at room T, that senses merons at higher T's, as well as their coexistence with skyrmions as T is lowered, indicating an on-demand thermally driven formation of either type of spin texture. Remarkably, an unconventional THE is also observed in absence of Lorentz force, and it is attributed to the interaction between charge carriers and magnetic field-induced chiral spin textures. These results expose Fe5-x GeTe2 as a promising candidate for the development of applications in skyrmionics/meronics due to the interplay between distinct but coexisting topological magnetic textures and unconventional transport of charge/heat carriers.
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Affiliation(s)
- Brian W Casas
- National High Magnetic Field Laboratory, Tallahassee, FL, 32310, USA
| | - Yue Li
- Materials Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Alex Moon
- National High Magnetic Field Laboratory, Tallahassee, FL, 32310, USA
- Department of Physics, Florida State University, Tallahassee, FL, 32306, USA
| | - Yan Xin
- National High Magnetic Field Laboratory, Tallahassee, FL, 32310, USA
| | - Conor McKeever
- Institute for Condensed Matter and Complex Systems, School of Physics and Astronomy, The University of Edinburgh, Edinburgh, EH9 3FD, UK
| | - Juan Macy
- National High Magnetic Field Laboratory, Tallahassee, FL, 32310, USA
- Department of Physics, Florida State University, Tallahassee, FL, 32306, USA
| | - Amanda K Petford-Long
- Materials Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Charudatta M Phatak
- Materials Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Elton J G Santos
- Institute for Condensed Matter and Complex Systems, School of Physics and Astronomy, The University of Edinburgh, Edinburgh, EH9 3FD, UK
- Higgs Centre for Theoretical Physics, The University of Edinburgh, Edinburgh, EH9 3FD, UK
- Donostia International Physics Center (DIPC), 20018, Donostia-San Sebastián, Basque Country, Spain
| | - Eun Sang Choi
- National High Magnetic Field Laboratory, Tallahassee, FL, 32310, USA
- Department of Physics, Florida State University, Tallahassee, FL, 32306, USA
| | - Luis Balicas
- National High Magnetic Field Laboratory, Tallahassee, FL, 32310, USA
- Department of Physics, Florida State University, Tallahassee, FL, 32306, USA
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16
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Paikaray B, Kuchibhotla M, Haldar A, Murapaka C. Skyrmion based majority logic gate by voltage controlled magnetic anisotropy in a nanomagnetic device. NANOTECHNOLOGY 2023; 34:225202. [PMID: 36827697 DOI: 10.1088/1361-6528/acbeb3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Accepted: 02/24/2023] [Indexed: 06/18/2023]
Abstract
Magnetic skyrmions are topologically protected spin textures and they are suitable for future logic-in-memory applications for energy-efficient, high-speed information processing and computing technologies. In this work, we have demonstrated skyrmion-based 3 bit majority logic gate using micromagnetic simulations. The skyrmion motion is controlled by introducing agatethat works on voltage controlled magnetic anisotropy. Here, the inhomogeneous magnetic anisotropy behaves as a tunable potential barrier/well that modulates the skyrmion trajectory in the structure for the successful implementation of the majority logic gate. In addition, several other effects such as skyrmion-skyrmion topological repulsion, skyrmion-edge repulsion, spin-orbit torque and skyrmion Hall effect have been shown to govern the logic functionalities. We have systematically presented the robust logic operations by varying the current density, magnetic anisotropy, voltage-controlled gate dimension and geometrical parameters of the logic device. The skyrmion Hall angle is monitored to understand the trajectory and stability of the skyrmion as a function of time in the logic device. The results demonstrate a novel method to achieve majority logic by using voltage controlled magnetic anisotropy which further opens up a new route for skyrmion-based low-power and high-speed computing devices.
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Affiliation(s)
- Bibekananda Paikaray
- Department of Materials Science and Metallurgical Engineering, Indian Institute of Technology Hyderabad, Kandi 502284, Telangana, India
| | - Mahathi Kuchibhotla
- Department of Physics, Indian Institute of Technology Hyderabad, Kandi 502284, Telangana, India
| | - Arabinda Haldar
- Department of Physics, Indian Institute of Technology Hyderabad, Kandi 502284, Telangana, India
| | - Chandrasekhar Murapaka
- Department of Materials Science and Metallurgical Engineering, Indian Institute of Technology Hyderabad, Kandi 502284, Telangana, India
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17
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Yang S, Son JW, Ju TS, Tran DM, Han HS, Park S, Park BH, Moon KW, Hwang C. Magnetic Skyrmion Transistor Gated with Voltage-Controlled Magnetic Anisotropy. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2208881. [PMID: 36511234 DOI: 10.1002/adma.202208881] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 11/27/2022] [Indexed: 06/17/2023]
Abstract
The paradigm shift of information carriers from charge to spin has long been awaited in modern electronics. The invention of the spin-information transistor is expected to be an essential building block for the future development of spintronics. Here, a proof-of-concept experiment of a magnetic skyrmion transistor working at room temperature, which has never been demonstrated experimentally, is introduced. With the spatially uniform control of magnetic anisotropy, the shape and topology of a skyrmion when passing the controlled area can be maintained. The findings will open a new route toward the design and realization of skyrmion-based spintronic devices in the near future.
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Affiliation(s)
- Seungmo Yang
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Jong Wan Son
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Tae-Seong Ju
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
- Department of Physics, Pusan National University, Busan, 46241, Republic of Korea
| | - Duc Minh Tran
- Division of Quantum Phases and Devices, Department of Physics, Konkuk University, Seoul, 05029, Republic of Korea
| | - Hee-Sung Han
- Department of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Sungkyun Park
- Department of Physics, Pusan National University, Busan, 46241, Republic of Korea
| | - Bae Ho Park
- Division of Quantum Phases and Devices, Department of Physics, Konkuk University, Seoul, 05029, Republic of Korea
| | - Kyoung-Woong Moon
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Chanyong Hwang
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
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18
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Dash A, Ojha B, Mohanty S, Moharana AK, Bedanta S. Device geometry dependent deterministic skyrmion generation from a skyrmionium. NANOTECHNOLOGY 2023; 34:185001. [PMID: 36716477 DOI: 10.1088/1361-6528/acb714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 01/30/2023] [Indexed: 06/18/2023]
Abstract
A magnetic skyrmionium can be perceived as an association of two magnetic skyrmions with opposite topological charges. In this work, we have investigated the transformation of skyrmionium into multi-skyrmionic states via domain wall pairs in three different devices with variable geometric configurations. The same device geometries are considered for single ferromagnetic layer and synthetic antiferromagnetic system. It is observed that by tuning the current density, deterministic generation of skyrmions is possible via the spin transfer torque. The proposed device is efficiently adjustable to change the number of skyrmions also at room temperature. The results may lead to development of skyrmion-based devices for neuromorphic and unconventional computing.
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Affiliation(s)
- Adyashakti Dash
- Laboratory for Nanomagnetism and Magnetic Materials (LNMM), School of Physical Sciences, National Institute of Science Education and Research (NISER), An OCC of Homi Bhabha National Institute (HBNI), Jatni, Odisha 752050, India
| | - Brindaban Ojha
- Laboratory for Nanomagnetism and Magnetic Materials (LNMM), School of Physical Sciences, National Institute of Science Education and Research (NISER), An OCC of Homi Bhabha National Institute (HBNI), Jatni, Odisha 752050, India
| | - Shaktiranjan Mohanty
- Laboratory for Nanomagnetism and Magnetic Materials (LNMM), School of Physical Sciences, National Institute of Science Education and Research (NISER), An OCC of Homi Bhabha National Institute (HBNI), Jatni, Odisha 752050, India
| | - Ashish Kumar Moharana
- Laboratory for Nanomagnetism and Magnetic Materials (LNMM), School of Physical Sciences, National Institute of Science Education and Research (NISER), An OCC of Homi Bhabha National Institute (HBNI), Jatni, Odisha 752050, India
| | - Subhankar Bedanta
- Laboratory for Nanomagnetism and Magnetic Materials (LNMM), School of Physical Sciences, National Institute of Science Education and Research (NISER), An OCC of Homi Bhabha National Institute (HBNI), Jatni, Odisha 752050, India
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19
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Sivasubramani S, Paikaray B, Kuchibhotla M, Haldar A, Murapaka C, Acharyya A. Skyrmion based 3D low complex runtime reconfigurable architecture design methodology of universal logic gate. NANOTECHNOLOGY 2023; 34:13LT01. [PMID: 36584387 DOI: 10.1088/1361-6528/acaf32] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 12/29/2022] [Indexed: 06/17/2023]
Abstract
In this study, we introduce the area efficient low complex runtime reconfigurable architecture design methodology based on Skyrmion logic for universal logic gate (ULG) i.e. NOR/NAND implementation using micromagnetic simulations. We have modelled the two input 3D device structure using bilayer ferromagnet/heavy metal where the magnetic tunnel junctions inject and detect the input and output skyrmions by exploiting the input reversal mechanism. The implementation of NOR and NAND is performed using this same device where it is reconfigured runtime with enhanced tunability by the ON and OFF state of current passing through a non magnetic metallic gate respectively. This gate acts as a barrier for skyrmion motion (additional control mechanism) to realize the required Skyrmion logic output states. To the best of authors's knowledge the boolean optimizations and the mapping logic have been presented for the first time to demonstrate the functionalities of the NOR/NAND implementation. This proposed architecture design methodology of ULG leads to reduced device footprint with regard to the number of thin film structures proposed, low complexity in terms of fabrication and also providing runtime reconfigurability to reduce the number of physical designs to achieve all truth table entries (∼75% device footprint reduction). The proposed 3D ULG architecture design benefits from the miniaturization resulting in opening up a new perspective for magneto-logic devices.
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Affiliation(s)
- Santhosh Sivasubramani
- Advanced Embedded Systems and IC Design Laboratory, Department of Electrical Engineering, Indian Institute of Technology (IIT) Hyderabad, 502284, India
| | - Bibekananda Paikaray
- Department of Materials Science and Metallurgical Engineering, Indian Institute of Technology (IIT) Hyderabad, 502284, India
| | - Mahathi Kuchibhotla
- Department of Physics, Indian Institute of Technology (IIT) Hyderabad, 502284, India
| | - Arabinda Haldar
- Department of Physics, Indian Institute of Technology (IIT) Hyderabad, 502284, India
| | - Chandrasekhar Murapaka
- Department of Materials Science and Metallurgical Engineering, Indian Institute of Technology (IIT) Hyderabad, 502284, India
| | - Amit Acharyya
- Advanced Embedded Systems and IC Design Laboratory, Department of Electrical Engineering, Indian Institute of Technology (IIT) Hyderabad, 502284, India
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20
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Bindal N, Raj RK, Kaushik BK. Antiferromagnetic skyrmion-based high speed diode. NANOSCALE ADVANCES 2023; 5:450-458. [PMID: 36756271 PMCID: PMC9846466 DOI: 10.1039/d2na00748g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 11/16/2022] [Indexed: 06/18/2023]
Abstract
Antiferromagnetic (AFM) skyrmions are favored over ferromagnetic (FM) skyrmions as they can be driven parallel to in-plane driving currents and eventually prevent the annihilation at the edges of nanotrack. In this study, an AFM skyrmion-based diode is proposed to realize the one-way skyrmion motion that is crucial for data processing in nanoelectronic and spintronic devices. The skyrmion transport is controlled by exploiting the staircase notch region in the middle of the nanotrack. By virtue of this, the micromagnetic interaction energy between the skyrmion and the notch edges generates a potential gradient that further gives rise to repulsive forces on the skyrmion. The resultant of the forces from the driving current and edge repulsions make the skyrmion move along the notch region to overcome the device window and reach the detection region. The notch is designed in such a way that it prevents the movement of the skyrmion in the reverse direction, thereby achieving diode functionality. The proposed device offers processing speed in the order of 103 m s-1, hence paving the way for the development of energy-efficient and high-speed devices in antiferromagnetic spintronics.
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Affiliation(s)
- Namita Bindal
- Department of Electronics and Communication Engineering, Indian Institute of Technology Roorkee Uttarakhand India 247667
| | - Ravish Kumar Raj
- Department of Electronics and Communication Engineering, Indian Institute of Technology Roorkee Uttarakhand India 247667
| | - Brajesh Kumar Kaushik
- Department of Electronics and Communication Engineering, Indian Institute of Technology Roorkee Uttarakhand India 247667
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21
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Yang S, Ju TS, Kim C, Kim HJ, An K, Moon KW, Park S, Hwang C. Magnetic Field Magnitudes Needed for Skyrmion Generation in a General Perpendicularly Magnetized Film. NANO LETTERS 2022; 22:8430-8436. [PMID: 36282733 PMCID: PMC9650724 DOI: 10.1021/acs.nanolett.2c02268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 10/08/2022] [Indexed: 06/16/2023]
Abstract
Due to its topological protection, the magnetic skyrmion has been intensively studied for both fundamental aspects and spintronics applications. However, despite recent advancements in skyrmion research, the deterministic creation of isolated skyrmions in a generic perpendicularly magnetized film is still one of the most essential and challenging techniques. Here, we present a method to create magnetic skyrmions in typical perpendicular magnetic anisotropy (PMA) films by applying a magnetic field pulse and a method to determine the magnitude of the required external magnetic fields. Furthermore, to demonstrate the usefulness of this result for future skyrmion research, we also experimentally study the PMA dependence on the minimum size of skyrmions. Although field-driven skyrmion generation is unsuitable for device application, this result can provide an easier approach for obtaining isolated skyrmions, making skyrmion-based research more accessible.
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Affiliation(s)
- Seungmo Yang
- Quantum
Spin Team, Korea Research Institute of Standards
and Science, Daejeon34113, Republic of Korea
| | - Tae-Seong Ju
- Quantum
Spin Team, Korea Research Institute of Standards
and Science, Daejeon34113, Republic of Korea
- Department
of Physics, Pusan National University, Busan46241, Republic of Korea
| | - Changsoo Kim
- Quantum
Spin Team, Korea Research Institute of Standards
and Science, Daejeon34113, Republic of Korea
| | - Hyun-Joong Kim
- Quantum
Spin Team, Korea Research Institute of Standards
and Science, Daejeon34113, Republic of Korea
| | - Kyongmo An
- Quantum
Spin Team, Korea Research Institute of Standards
and Science, Daejeon34113, Republic of Korea
| | - Kyoung-Woong Moon
- Quantum
Spin Team, Korea Research Institute of Standards
and Science, Daejeon34113, Republic of Korea
| | - Sungkyun Park
- Department
of Physics, Pusan National University, Busan46241, Republic of Korea
| | - Chanyong Hwang
- Quantum
Spin Team, Korea Research Institute of Standards
and Science, Daejeon34113, Republic of Korea
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22
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Song M, You M, Yang S, Ju TS, Moon KW, Hwang C, Kim KW, Park AMG, Kim KJ. Universal Hopping Motion Protected by Structural Topology. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2203275. [PMID: 35985670 DOI: 10.1002/adma.202203275] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 07/28/2022] [Indexed: 06/15/2023]
Abstract
A scaling law elucidates the universality in nature, presiding over many physical phenomena which seem unrelated. Thus, exploring the universality class of scaling law in a particular system enlightens its physical nature in relevance to other systems and sometimes unearths an unprecedented new dynamic phase. Here, the dynamics of weakly driven magnetic skyrmions are investigated, and its scaling law is compared with the motion of a magnetic domain wall (DW) creep. This study finds that the skyrmion does not follow the scaling law of the DW creep in 2D space but instead shows a hopping behavior similar to that of the particle-like DW in 1D confinement. In addition, the hopping law satisfies even when a topological charge of the skyrmion is removed. Therefore, the distinct scaling behavior between the magnetic skyrmion and the DW stems from a general principle beyond the topological charge. This study demonstrates that the hopping behavior of skyrmions originates from the bottleneck process induced by DW segments with diverging collective lengths, which is inevitable in any closed-shape spin structure in 2D. This work reveals that the structural topology of magnetic texture determines the universality class of its weakly driven motion, which is distinguished from the universality class of magnetic DW creep.
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Affiliation(s)
- Moojune Song
- Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Mujin You
- Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Seungmo Yang
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Tae-Seong Ju
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Kyoung-Woong Moon
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Chanyong Hwang
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Kyoung-Whan Kim
- Center for Spintronics, Korea Institute of Science and Technology, Seoul, 02792, Republic of Korea
| | - Albert Min Gyu Park
- Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Kab-Jin Kim
- Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
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23
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Li D, Haldar S, Heinze S. Strain-Driven Zero-Field Near-10 nm Skyrmions in Two-Dimensional van der Waals Heterostructures. NANO LETTERS 2022; 22:7706-7713. [PMID: 36121771 DOI: 10.1021/acs.nanolett.2c03287] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Magnetic skyrmions─localized chiral spin structures─show great promise for spintronic applications. The recent discovery of two-dimensional (2D) magnets opened new opportunities for topological spin structures in atomically thin van der Waals (vdW) materials. Despite recent progress in stabilizing metastable skyrmions in 2D magnets, their lifetime, essential for applications, has not been explored yet. Here, using first-principles calculations and atomistic spin simulations, we predict that compressive strain leads to stabilizing zero-field skyrmions with diameters close to 10 nm in a Fe3GeTe2/germanene vdW heterostructure. The origin of these unique skyrmions is attributed to the high tunability of Dzyaloshinskii-Moriya interaction and magnetocrystalline anisotropy energy by strain, which generally holds for Fe3GeTe2 heterostructures with buckled substrates. Furthermore, we calculate the energy barriers protecting skyrmions against annihilation and their lifetimes using transition-state theory. We show that nanoscale skyrmions in strained Fe3GeTe2/germanene can be stable for hours at temperatures up to 20 K.
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Affiliation(s)
- Dongzhe Li
- CEMES, Université de Toulouse, CNRS, 29 rue Jeanne Marvig, F-31055 Toulouse, France
| | - Soumyajyoti Haldar
- Institute of Theoretical Physics and Astrophysics, University of Kiel, Leibnizstrasse 15, 24098 Kiel, Germany
| | - Stefan Heinze
- Institute of Theoretical Physics and Astrophysics, University of Kiel, Leibnizstrasse 15, 24098 Kiel, Germany
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24
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Nucleation and manipulation of single skyrmions using spin-polarized currents in antiferromagnetic skyrmion-based racetrack memories. Sci Rep 2022; 12:15225. [PMID: 36076059 PMCID: PMC9458664 DOI: 10.1038/s41598-022-19587-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 08/31/2022] [Indexed: 11/21/2022] Open
Abstract
In this work, an ultrafast nucleation of an isolated anti-ferromagnetic (AFM) skyrmion was reported in an AFM layer with DMi strengths of 0.47\documentclass[12pt]{minimal}
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\begin{document}$$\mathrm{mJ}/{\mathrm{m}}^{2}$$\end{document}mJ/m2 using spin-transfer torque by locally injecting pure spin currents into magnetic tracks. Besides, we revealed the key advantages of AFM skyrmion-based racetrack memories by comparing the motion of AFM and FM skyrmions driven by spin–orbit torques (SOTs) for different skyrmion sizes along racetrack memories with various notch sizes. Our results indicate that for AFM skyrmion, the skyrmion Hall effect does not exist during the skyrmion motion, therefore at small skyrmion sizes, we succeeded to overcome the repulsive forces developed in the notch area for low and large SOTs. The obtained findings were carefully analyzed by computing the variation of energy barriers associated with the notch for different skyrmion sizes using minimum energy path (MEP) calculations. We showed that the larger the skyrmion size, the harder it is to shrink the skyrmion in the notch which produces a high energy barrier (Eb) for large skyrmion sizes. Moreover, as the notch size increases, the skyrmion size shrinks further, and hence Eb increases proportionally. Nevertheless, we proved that AFM skyrmions are more efficient and flexible than FM skyrmions against boundary forces.
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25
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Zeng Z, Mehmood N, Ma Y, Wang J, Wang J, Liu Q. The skyrmion bags in an anisotropy gradient. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:395801. [PMID: 35850114 DOI: 10.1088/1361-648x/ac8216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 07/18/2022] [Indexed: 06/15/2023]
Abstract
Skyrmion bags as spin textures with arbitrary topological charge are expected to be the carriers in racetrack memory. Here, we theoretically and numerically investigated the dynamics of skyrmion bags in an anisotropy gradient. It is found that, without the boundary potential, the dynamics of skyrmion bags are dependent on the spin textures, and the velocity of skyrmionium withQ = 0 is faster than other skyrmion bags. However, when the skyrmion bags move along the boundary, the velocities of all skyrmion bags with differentQare same. In addition, we theoretically derived the dynamics of skyrmion bags in the two cases using the Thiele approach and discussed the scope of Thiele equation. Within a certain range, the simulation results are in good agreement with the analytically calculated results. Our findings provide an alternative way to manipulate the racetrack memory based on the skyrmion bags.
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Affiliation(s)
- Zhaozhuo Zeng
- Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - Nasir Mehmood
- Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - Yunxu Ma
- Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - Jianing Wang
- Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - Jianbo Wang
- Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000, People's Republic of China
- Key Laboratory for Special Function Materials and Structural Design of the Ministry of Education, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - Qingfang Liu
- Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000, People's Republic of China
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26
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Abstract
A key issue for skyrmion dynamics and devices are pinning effects present in real systems. While posing a challenge for the realization of conventional skyrmionics devices, exploiting pinning effects can enable non-conventional computing approaches if the details of the pinning in real samples are quantified and understood. We demonstrate that using thermal skyrmion dynamics, we can characterize the pinning of a sample and we ascertain the spatially resolved energy landscape. To understand the mechanism of the pinning, we probe the strong skyrmion size and shape dependence of the pinning. Magnetic microscopy imaging demonstrates that in contrast to findings in previous investigations, for large skyrmions the pinning originates at the skyrmion boundary and not at its core. The boundary pinning is strongly influenced by the very complex pinning energy landscape that goes beyond the conventional effective rigid quasi-particle description. This gives rise to complex skyrmion shape distortions and allows for dynamic switching of pinning sites and flexible tuning of the pinning. Skyrmions, topological spin textures, can be pinned by defects present in the material that hosts them, influencing their motion. Here, Gruber et al show that the skyrmions are pinned at their boundary where the finite size of the skyrmions governs their pinning, and they demonstrate that certain pinning sites can switched on and off in-situ.
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27
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Kern LM, Pfau B, Deinhart V, Schneider M, Klose C, Gerlinger K, Wittrock S, Engel D, Will I, Günther CM, Liefferink R, Mentink JH, Wintz S, Weigand M, Huang MJ, Battistelli R, Metternich D, Büttner F, Höflich K, Eisebitt S. Deterministic Generation and Guided Motion of Magnetic Skyrmions by Focused He +-Ion Irradiation. NANO LETTERS 2022; 22:4028-4035. [PMID: 35577328 PMCID: PMC9137908 DOI: 10.1021/acs.nanolett.2c00670] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 05/02/2022] [Indexed: 05/18/2023]
Abstract
Magnetic skyrmions are quasiparticles with nontrivial topology, envisioned to play a key role in next-generation data technology while simultaneously attracting fundamental research interest due to their emerging topological charge. In chiral magnetic multilayers, current-generated spin-orbit torques or ultrafast laser excitation can be used to nucleate isolated skyrmions on a picosecond time scale. Both methods, however, produce randomly arranged skyrmions, which inherently limits the precision on the location at which the skyrmions are nucleated. Here, we show that nanopatterning of the anisotropy landscape with a He+-ion beam creates well-defined skyrmion nucleation sites, thereby transforming the skyrmion localization into a deterministic process. This approach allows control of individual skyrmion nucleation as well as guided skyrmion motion with nanometer-scale precision, which is pivotal for both future fundamental studies of skyrmion dynamics and applications.
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Affiliation(s)
- Lisa-Marie Kern
- Max
Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, 12489 Berlin, Germany
| | - Bastian Pfau
- Max
Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, 12489 Berlin, Germany
- E-mail:
| | - Victor Deinhart
- Max
Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, 12489 Berlin, Germany
- Ferdinand-Braun-Institut
gGmbH, Leibniz-Institut für Höchstfrequenztechnik, 12489 Berlin, Germany
- Helmholtz-Zentrum
für Materialien und Energie GmbH, 14109 Berlin, Germany
| | - Michael Schneider
- Max
Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, 12489 Berlin, Germany
| | - Christopher Klose
- Max
Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, 12489 Berlin, Germany
| | - Kathinka Gerlinger
- Max
Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, 12489 Berlin, Germany
| | - Steffen Wittrock
- Max
Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, 12489 Berlin, Germany
| | - Dieter Engel
- Max
Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, 12489 Berlin, Germany
| | - Ingo Will
- Max
Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, 12489 Berlin, Germany
| | - Christian M. Günther
- Technische
Universität Berlin, Zentraleinrichtung Elektronenmikroskopie (ZELMI), 10623 Berlin, Germany
| | - Rein Liefferink
- Radboud
University, Institute for
Molecules and Materials (IMM), 6525 AJ Nijmegen, Netherlands
| | - Johan H. Mentink
- Radboud
University, Institute for
Molecules and Materials (IMM), 6525 AJ Nijmegen, Netherlands
| | - Sebastian Wintz
- Max
Planck Institute for Intelligent Systems, 70569 Stuttgart, Germany
| | - Markus Weigand
- Helmholtz-Zentrum
für Materialien und Energie GmbH, 14109 Berlin, Germany
| | - Meng-Jie Huang
- Deutsches
Elektronen-Synchrotron (DESY), 22607 Hamburg, Germany
| | | | - Daniel Metternich
- Helmholtz-Zentrum
für Materialien und Energie GmbH, 14109 Berlin, Germany
| | - Felix Büttner
- Helmholtz-Zentrum
für Materialien und Energie GmbH, 14109 Berlin, Germany
| | - Katja Höflich
- Ferdinand-Braun-Institut
gGmbH, Leibniz-Institut für Höchstfrequenztechnik, 12489 Berlin, Germany
- Helmholtz-Zentrum
für Materialien und Energie GmbH, 14109 Berlin, Germany
| | - Stefan Eisebitt
- Max
Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, 12489 Berlin, Germany
- Technische
Universität Berlin, Institut für
Optik und Atomare Physik, 10623 Berlin, Germany
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28
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Fan Y, Han X, Zhao X, Dong Y, Chen Y, Bai L, Yan S, Tian Y. Programmable Spin-Orbit Torque Multistate Memory and Spin Logic Cell. ACS NANO 2022; 16:6878-6885. [PMID: 35349269 DOI: 10.1021/acsnano.2c01930] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Controllable spin-orbit torque based nonvolatile memory is highly desired for constructing energy efficient reconfigurable logic-in-memory computing suitable for emerging data-intensive applications. Here, we report our exploration of the IrMn/Co/Ru/CoPt/CoO heterojunction as a potential candidate for applications in both multistate memory and programmable spin logic. The studied heterojunction can be programmed into four different magnetic configurations at will by tuning both the in-plane exchange bias at the interface of IrMn and Co layers and the out-of-plane exchange bias at the interface of CoPt and CoO layers. Moreover, on the basis of the controllable exchange bias effect, 10 states of nonvolatile memory and multiple logic-in-memory functions have been demonstrated. Our findings indicate that IrMn/Co/Ru/CoPt/CoO multilayered structures can be used as a building block for next-generation logic-in-memory and multifunctional multidimensional spintronic devices.
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Affiliation(s)
- Yibo Fan
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Xiang Han
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Xiaonan Zhao
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Yanan Dong
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Yanxue Chen
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Lihui Bai
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Shishen Yan
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
- Spintronics Institute, University of Jinan, Jinan 250022, China
| | - Yufeng Tian
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
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29
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Cui Q, Zhu Y, Ga Y, Liang J, Li P, Yu D, Cui P, Yang H. Anisotropic Dzyaloshinskii-Moriya Interaction and Topological Magnetism in Two-Dimensional Magnets Protected by P4̅ m2 Crystal Symmetry. NANO LETTERS 2022; 22:2334-2341. [PMID: 35266723 DOI: 10.1021/acs.nanolett.1c04803] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
As a fundamental magnetic parameter, Dzyaloshinskii-Moriya interaction (DMI), has gained a great deal of attention in the last two decades due to its critical role in formation of magnetic skyrmions. Recent discoveries of two-dimensional (2D) van der Waals (vdW) magnets has also gained a great deal of attention due to appealing physical properties, such as gate tunability, flexibility, and miniaturization. Intensive studies have shown that isotropic DMI stabilizes ferromagnetic (FM) topological spin textures in 2D magnets or their corresponding heterostructures. However, the investigation of anisotropic DMI and antiferromagnetic (AFM) topological spin configurations remains elusive. Here, we propose and demonstrate a family of 2D magnets with P4m2 symmetry-protected anisotropic DMI. More interestingly, various topological spin configurations, including FM/AFM antiskyrmion and AFM vortex-antivortex pair, emerge in this family. These results give a general method to design anisotropic DMI and pave the way toward topological magnetism in 2D materials using crystal symmetry.
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Affiliation(s)
- Qirui Cui
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
- Faculty of Science and Engineering, University of Nottingham Ningbo China, Ningbo 315100, China
| | - Yingmei Zhu
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | - Yonglong Ga
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | - Jinghua Liang
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | - Peng Li
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | - Dongxing Yu
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | - Ping Cui
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
- Faculty of Science and Engineering, University of Nottingham Ningbo China, Ningbo 315100, China
| | - Hongxin Yang
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
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30
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Yu D, Yang H, Chshiev M, Fert A. Skyrmions-based logic gates in one single nanotrack completely reconstructed via chirality barrier. Natl Sci Rev 2022; 9:nwac021. [PMID: 36713589 PMCID: PMC9874028 DOI: 10.1093/nsr/nwac021] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 01/06/2022] [Accepted: 01/07/2022] [Indexed: 02/01/2023] Open
Abstract
Logic gates based on magnetic elements are promising candidates for logic-in-memory applications with non-volatile data retention, near-zero leakage and scalability. In such spin-based logic devices, however, the multi-strip structure and fewer functions are obstacles to improving integration and reducing energy consumption. Here we propose a skyrmions-based single-nanotrack logic family including AND, OR, NOT, NAND, NOR, XOR and XNOR that can be implemented and reconstructed by building and switching the Dzyaloshinskii-Moriya interaction (DMI) chirality barrier on a racetrack memory. Besides the pinning effect of the DMI chirality barrier on skyrmions, the annihilation, fusion and shunting of two skyrmions with opposite chirality are also achieved and demonstrated via local reversal of the DMI, which are necessary for the design of an engineer programmable logic nanotrack, transistor and complementary racetrack memory.
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Affiliation(s)
- Dongxing Yu
- Quantum Functional Materials Laboratory, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | | | - Mairbek Chshiev
- Université Grenoble Alpes, CEA, CNRS, Spintec, Grenoble 38000, France,Institut Universitaire de France (IUF), Paris 75231, France
| | - Albert Fert
- Université Paris-Saclay, Unité Mixte de Physique CNRS-Thales, Palaiseau 91767, France
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31
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Manipulation of Skyrmion Motion Dynamics for Logical Device Application Mediated by Inhomogeneous Magnetic Anisotropy. NANOMATERIALS 2022; 12:nano12020278. [PMID: 35055295 PMCID: PMC8779807 DOI: 10.3390/nano12020278] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 01/09/2022] [Accepted: 01/10/2022] [Indexed: 02/04/2023]
Abstract
Magnetic skyrmions are promising potential information carriers for future spintronic devices owing to their nanoscale size, non-volatility and high mobility. In this work, we demonstrate the controlled manipulation of skyrmion motion and its implementation in a new concept of racetrack logical device by introducing an inhomogeneous perpendicular magnetic anisotropy (PMA) via micromagnetic simulation. Here, the inhomogeneous PMA can be introduced by a capping nano-island that serves as a tunable potential barriers/well which can effectively modulate the size and shape of isolated skyrmion. Using the inhomogeneous PMA in skyrmion-based racetrack enables the manipulation of skyrmion motion behaviors, for instance, blocking, trapping or allowing passing the injected skyrmion. In addition, the skyrmion trapping operation can be further exploited in developing special designed racetrack devices with logic AND and NOT, wherein a set of logic AND operations can be realized via skyrmion–skyrmion repulsion between two skyrmions. These results indicate an effective method for tailoring the skyrmion structures and motion behaviors by using inhomogeneous PMA, which further provide a new pathway to all-electric skyrmion-based memory and logic devices.
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32
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Stepanova M, Masell J, Lysne E, Schoenherr P, Köhler L, Paulsen M, Qaiumzadeh A, Kanazawa N, Rosch A, Tokura Y, Brataas A, Garst M, Meier D. Detection of Topological Spin Textures via Nonlinear Magnetic Responses. NANO LETTERS 2022; 22:14-21. [PMID: 34935368 PMCID: PMC8759079 DOI: 10.1021/acs.nanolett.1c02723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 11/29/2021] [Indexed: 06/14/2023]
Abstract
Topologically nontrivial spin textures, such as skyrmions and dislocations, display emergent electrodynamics and can be moved by spin currents over macroscopic distances. These unique properties and their nanoscale size make them excellent candidates for the development of next-generation race-track memory and unconventional computing. A major challenge for these applications and the investigation of nanoscale magnetic structures in general is the realization of suitable detection schemes. We study magnetic disclinations, dislocations, and domain walls in FeGe and reveal pronounced responses that distinguish them from the helimagnetic background. A combination of magnetic force microscopy (MFM) and micromagnetic simulations links the response to the local magnetic susceptibility, that is, characteristic changes in the spin texture driven by the MFM tip. On the basis of the findings, which we explain using nonlinear response theory, we propose a read-out scheme using superconducting microcoils, presenting an innovative approach for detecting topological spin textures and domain walls in device-relevant geometries.
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Affiliation(s)
- Mariia Stepanova
- Department
of Materials Science and Engineering, Norwegian
University of Science and Technology (NTNU), Trondheim 7491, Norway
- Center
for Quantum Spintronics, Department of Physics,
Norwegian University of Science and Technology (NTNU), Trondheim 7491, Norway
| | - Jan Masell
- RIKEN
Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
| | - Erik Lysne
- Department
of Materials Science and Engineering, Norwegian
University of Science and Technology (NTNU), Trondheim 7491, Norway
- Center
for Quantum Spintronics, Department of Physics,
Norwegian University of Science and Technology (NTNU), Trondheim 7491, Norway
| | - Peggy Schoenherr
- School
of Materials Science and Engineering, University
of New South Wales, Sydney, Sydney New South Wales 2052, Australia
- ARC
Centre of Excellence in Future Low-Energy Electronics Technologies
(FLEET), UNSW Sydney, Sydney, NSW 2052, Australia
| | - Laura Köhler
- Institute
of Theoretical Solid State Physics, Karlsruhe
Institute of Technology, 76049 Karlsruhe, Germany
| | - Michael Paulsen
- Physikalisch-Technische
Bundesanstalt (PTB), Berlin 10587, Germany
| | - Alireza Qaiumzadeh
- Center
for Quantum Spintronics, Department of Physics,
Norwegian University of Science and Technology (NTNU), Trondheim 7491, Norway
| | - Naoya Kanazawa
- Department
of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
| | - Achim Rosch
- Institute
for Theoretical Physics, University of Cologne, Cologne 50937, Germany
| | - Yoshinori Tokura
- RIKEN
Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan
- Department
of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
- Tokyo
College, University of Tokyo, Tokyo 113−8656, Japan
| | - Arne Brataas
- Center
for Quantum Spintronics, Department of Physics,
Norwegian University of Science and Technology (NTNU), Trondheim 7491, Norway
| | - Markus Garst
- Institute
of Theoretical Solid State Physics, Karlsruhe
Institute of Technology, 76049 Karlsruhe, Germany
- Institute
for Quantum Materials and Technology, Karlsruhe
Institute of Technology, 76021 Karlsruhe, Germany
| | - Dennis Meier
- Department
of Materials Science and Engineering, Norwegian
University of Science and Technology (NTNU), Trondheim 7491, Norway
- Center
for Quantum Spintronics, Department of Physics,
Norwegian University of Science and Technology (NTNU), Trondheim 7491, Norway
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33
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Bindal N, Nisar A, Dhull S, Kaushik BK. Magnetic Skyrmions: Recent advances and applications. IEEE NANOTECHNOLOGY MAGAZINE 2021. [DOI: 10.1109/mnano.2021.3113215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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34
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Yang S, Moon KW, Ju TS, Kim C, Kim HJ, Kim J, Tran BX, Hong JI, Hwang C. Electrical Generation and Deletion of Magnetic Skyrmion-Bubbles via Vertical Current Injection. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2104406. [PMID: 34569658 DOI: 10.1002/adma.202104406] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 08/28/2021] [Indexed: 06/13/2023]
Abstract
The magnetic skyrmion is a topologically protected spin texture that has attracted much attention as a promising information carrier because of its distinct features of suitability for high-density storage, low power consumption, and stability. One of the skyrmion devices proposed so far is the skyrmion racetrack memory, which is the skyrmion version of the domain-wall racetrack memory. For application in devices, skyrmion racetrack memory requires electrical generation, deletion, and displacement of isolated skyrmions. Despite the progress in experimental demonstrations of skyrmion generation, deletion, and displacement, these three operations have yet to be realized in one device. Here, a route for generating and deleting isolated skyrmion-bubbles through vertical current injection with an explanation of its microscopic origin is presented. By combining the proposed skyrmion-bubble generation/deletion method with the spin-orbit-torque-driven skyrmion shift, a proof-of-concept experimental demonstration of the skyrmion racetrack memory operation in a three-terminal device structure is provided.
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Affiliation(s)
- Seungmo Yang
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Kyoung-Woong Moon
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Tae-Seong Ju
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Changsoo Kim
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Hyun-Joong Kim
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Juran Kim
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Bao Xuan Tran
- Department of Emerging Materials Science, DGIST, Daegu, 42988, Republic of Korea
| | - Jung-Il Hong
- Department of Emerging Materials Science, DGIST, Daegu, 42988, Republic of Korea
| | - Chanyong Hwang
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
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35
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Tan AKC, Ho P, Lourembam J, Huang L, Tan HK, Reichhardt CJO, Reichhardt C, Soumyanarayanan A. Visualizing the strongly reshaped skyrmion Hall effect in multilayer wire devices. Nat Commun 2021; 12:4252. [PMID: 34253721 PMCID: PMC8275747 DOI: 10.1038/s41467-021-24114-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 05/28/2021] [Indexed: 12/02/2022] Open
Abstract
Magnetic skyrmions are nanoscale spin textures touted as next-generation computing elements. When subjected to lateral currents, skyrmions move at considerable speeds. Their topological charge results in an additional transverse deflection known as the skyrmion Hall effect (SkHE). While promising, their dynamic phenomenology with current, skyrmion size, geometric effects and disorder remain to be established. Here we report on the ensemble dynamics of individual skyrmions forming dense arrays in Pt/Co/MgO wires by examining over 20,000 instances of motion across currents and fields. The skyrmion speed reaches 24 m/s in the plastic flow regime and is surprisingly robust to positional and size variations. Meanwhile, the SkHE saturates at ∼22∘, is substantially reshaped by the wire edge, and crucially increases weakly with skyrmion size. Particle model simulations suggest that the SkHE size dependence — contrary to analytical predictions — arises from the interplay of intrinsic and pinning-driven effects. These results establish a robust framework to harness SkHE and achieve high-throughput skyrmion motion in wire devices. Skyrmions - nanoscale, topological spin textures - are promising elements for next-generation computing due to their efficient coupling to currents in racetrack devices. Here, Tan et al. examine over 20,000 instances of current induced skyrmion motion to unveil a comprehensive picture of skyrmion dynamics across currents and fields.
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Affiliation(s)
- Anthony K C Tan
- Data Storage Institute, Agency for Science, Technology & Research (A*STAR), Singapore, Singapore.,Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | - Pin Ho
- Data Storage Institute, Agency for Science, Technology & Research (A*STAR), Singapore, Singapore. .,Institute of Materials Research & Engineering, Agency for Science, Technology & Research (A*STAR), Singapore, Singapore.
| | - James Lourembam
- Data Storage Institute, Agency for Science, Technology & Research (A*STAR), Singapore, Singapore.,Institute of Materials Research & Engineering, Agency for Science, Technology & Research (A*STAR), Singapore, Singapore
| | - Lisen Huang
- Data Storage Institute, Agency for Science, Technology & Research (A*STAR), Singapore, Singapore.,Institute of Materials Research & Engineering, Agency for Science, Technology & Research (A*STAR), Singapore, Singapore
| | - Hang Khume Tan
- Data Storage Institute, Agency for Science, Technology & Research (A*STAR), Singapore, Singapore.,Institute of Materials Research & Engineering, Agency for Science, Technology & Research (A*STAR), Singapore, Singapore
| | - Cynthia J O Reichhardt
- Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Charles Reichhardt
- Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Anjan Soumyanarayanan
- Data Storage Institute, Agency for Science, Technology & Research (A*STAR), Singapore, Singapore. .,Institute of Materials Research & Engineering, Agency for Science, Technology & Research (A*STAR), Singapore, Singapore. .,Physics Department, National University of Singapore, Singapore, Singapore.
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Ohara K, Zhang X, Chen Y, Wei Z, Ma Y, Xia J, Zhou Y, Liu X. Confinement and Protection of Skyrmions by Patterns of Modified Magnetic Properties. NANO LETTERS 2021; 21:4320-4326. [PMID: 33950694 DOI: 10.1021/acs.nanolett.1c00865] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Magnetic skyrmions are versatile topological excitations that can be used as nonvolatile information carriers. The confinement of skyrmions in channels is fundamental for any application based on the accumulation and transport of skyrmions. Here, we report a method that allows effective position control of skyrmions in designed channels by engineered energy barriers and wells, which is realized in a magnetic multilayer film by harnessing the boundaries of patterns with modified magnetic properties. We experimentally and computationally demonstrate that skyrmions can be attracted or repelled by the boundaries of areas with modified perpendicular magnetic anisotropy and Dzyaloshinskii-Moriya interaction. By fabricating square and stripe patterns with modified magnetic properties, we show the possibility of building reliable channels for confinement, accumulation, and transport of skyrmions, which effectively protect skyrmions from being destroyed at the device edges. Our results are useful for the design of spintronic applications using either static or dynamic skyrmions.
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Affiliation(s)
- Kentaro Ohara
- Department of Electrical and Computer Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553, Japan
| | - Xichao Zhang
- Department of Electrical and Computer Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553, Japan
| | - Yinling Chen
- Department of Electrical and Computer Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553, Japan
| | - Zonhan Wei
- School of Mechanics and Engineering Science, Zhengzhou University, Zhengzhou 450001, China
| | - Yungui Ma
- State Key Lab of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Jing Xia
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, China
| | - Yan Zhou
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, China
| | - Xiaoxi Liu
- Department of Electrical and Computer Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553, Japan
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Ognev AV, Kolesnikov AG, Kim YJ, Cha IH, Sadovnikov AV, Nikitov SA, Soldatov IV, Talapatra A, Mohanty J, Mruczkiewicz M, Ge Y, Kerber N, Dittrich F, Virnau P, Kläui M, Kim YK, Samardak AS. Magnetic Direct-Write Skyrmion Nanolithography. ACS NANO 2020; 14:14960-14970. [PMID: 33152236 DOI: 10.1021/acsnano.0c04748] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Magnetic skyrmions are stable spin textures with quasi-particle behavior and attract significant interest in fundamental and applied physics. The metastability of magnetic skyrmions at zero magnetic field is particularly important to enable, for instance, a skyrmion racetrack memory. Here, the results of the nucleation of stable skyrmions and formation of ordered skyrmion lattices by magnetic force microscopy in (Pt/CoFeSiB/W)n multilayers, exploiting the additive effect of the interfacial Dzyaloshinskii-Moriya interaction, are presented. The appropriate conditions under which skyrmion lattices are confined with a dense two-dimensional liquid phase are identified. A crucial parameter to control the skyrmion lattice characteristics and the number of scans resulting in the complete formation of a skyrmion lattice is the distance between two adjacent scanning lines of a magnetic force microscopy probe. The creation of skyrmion patterns with complex geometry is demonstrated, and the physical mechanism of direct magnetic writing of skyrmions is comprehended by micromagnetic simulations. This study shows a potential of a direct-write (maskless) skyrmion (topological) nanolithography with sub-100 nm resolution, where each skyrmion acts as a pixel in the final topological image.
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Affiliation(s)
- A V Ognev
- School of Natural Sciences, Far Eastern Federal University, Vladivostok 690950, Russia
| | - A G Kolesnikov
- School of Natural Sciences, Far Eastern Federal University, Vladivostok 690950, Russia
| | - Yong Jin Kim
- Department of Materials Science and Engineering, Korea University, Seoul 02841, Republic of Korea
| | - In Ho Cha
- Department of Materials Science and Engineering, Korea University, Seoul 02841, Republic of Korea
| | - A V Sadovnikov
- Laboratory "Metamaterials", Saratov State University, Saratov 410012, Russia
- Kotel'nikov Institute of Radioengineering and Electronics, Russian Academy of Sciences, Moscow 125009, Russia
| | - S A Nikitov
- Laboratory "Metamaterials", Saratov State University, Saratov 410012, Russia
- Kotel'nikov Institute of Radioengineering and Electronics, Russian Academy of Sciences, Moscow 125009, Russia
| | - I V Soldatov
- Leibniz Institute for Solid State and Material Research (IFW-Dresden), Dresden 01069, Germany
- Institute of Natural Sciences and Mathematic, Ural Federal University, Yekaterinburg 620075, Russia
| | - A Talapatra
- Indian Institute of Technology, Hyderabad 502285, India
| | - J Mohanty
- Indian Institute of Technology, Hyderabad 502285, India
| | - M Mruczkiewicz
- Institute of Electrical Engineering, SAS, Bratislava 841 04, Slovakia
- Centre for Advanced Materials Application (CEMEA), Slovak Academy of Sciences, Bratislava 845 11, Slovakia
| | - Y Ge
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Mainz 55128, Germany
| | - N Kerber
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Mainz 55128, Germany
| | - F Dittrich
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Mainz 55128, Germany
| | - P Virnau
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Mainz 55128, Germany
| | - M Kläui
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Mainz 55128, Germany
| | - Young Keun Kim
- Department of Materials Science and Engineering, Korea University, Seoul 02841, Republic of Korea
| | - A S Samardak
- School of Natural Sciences, Far Eastern Federal University, Vladivostok 690950, Russia
- National Research South Ural State University, Chelyabinsk 454080, Russia
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38
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Zhou D, Huang J, Yan H, Zhang J, Lu L, Xu P, Li G. Luminescent, Wide-Band Gap Solar Cells with a Photovoltage up to 1.75 V through a Heterostructured Light-Absorbing Layer. ACS APPLIED MATERIALS & INTERFACES 2020; 12:50527-50533. [PMID: 33140637 DOI: 10.1021/acsami.0c16032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The development of photovoltaic devices with a high output voltage offers great opportunities for emerging internet of things (IoT) sensors and low-power-consumption electronics. However, the photovoltage of solar cells is yet to satisfy the requirement of driving voltage for most applications. Here, we demonstrate a wide-band gap CsPbBr3-based solar cell with a heterostructured light absorber based on amino acid-modulated CsPbBr3 and CdSe quantum dots (QDs). Compared with the single absorbing layer device, the heterostructured device exhibits a low nonradiative recombination loss, which is strongly correlated to the high external electroluminescence of the device. In addition, in the heterostructured solar cells, carrier transfer from the perovskite to CdSe QDs induces the conduction band bending of CdSe QDs, leading to a large splitting of the quasi-Fermi levels. As a result, a remarkable photovoltage up to 1.75 V is achieved for the wide-band gap solar cells, representing an extremely low voltage deficit of 250 mV. Furthermore, the CsPbBr3-based solar cells exhibit a weak light intensity dependence, showing a photovoltage of 1.59 V under room light conditions. Our work not only provides an effective approach for the design of high-photovoltage solar cells but also paves the ways of using photovoltaic devices for various applications with low driving voltage schemes.
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Affiliation(s)
- Dingjian Zhou
- College of Electronics and Information Engineering, Shenzhen University, Shenzhen 518060, P. R. China
| | - Jincheng Huang
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, P. R. China
| | - Huibo Yan
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, P. R. China
| | - Jianfeng Zhang
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, P. R. China
| | - Lei Lu
- School of Electronic and Computer Engineering, Shenzhen Graduate School, Peking University, Shenzhen 518055, China
| | - Ping Xu
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, P. R. China
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, P. R. China
| | - Guijun Li
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, P. R. China
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, P. R. China
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39
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Talapatra A, Adeyeye AO. Linear chains of nanomagnets: engineering the effective magnetic anisotropy. NANOSCALE 2020; 12:20933-20944. [PMID: 33090176 DOI: 10.1039/d0nr06026g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
This paper investigates the control of effective magnetic anisotropy in Permalloy linear chain arrays, achieved by tuning the symmetry arrangement of the ellipsoidal nanomagnets and the film thickness. When the ellipsoidal nanomagnets are coupled along their easy axis, stronger effective magnetic anisotropy is achieved compared to when the nanomagnets are coupled along their hard axis. A clear transition from a single domain state to a combination of complex flux closure states such as a vortex or double vortices is observed at different applied field angles when the film thickness is varied in the range from 20 nm to 100 nm. Tunable microwave absorption spectra, obtained by ferromagnetic resonance spectroscopy, established the complex interplay between the shape anisotropy and magnetostatic interactions, which becomes more intriguing at different film thicknesses and applied field angles. The micromagnetic simulations are in good agreement with the experimental results. Our results demonstrate possible ways of manipulating the effective magnetic anisotropy in arrays of nanomagnets for magnonic and microwave applications.
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Affiliation(s)
- A Talapatra
- Information Storage Materials Laboratory, Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576.
| | - A O Adeyeye
- Information Storage Materials Laboratory, Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576. and Department of Physics, Durham University, South Rd, Durham, DH1 3LE, UK
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40
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Zhang X, Zhou Y, Mee Song K, Park TE, Xia J, Ezawa M, Liu X, Zhao W, Zhao G, Woo S. Skyrmion-electronics: writing, deleting, reading and processing magnetic skyrmions toward spintronic applications. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:143001. [PMID: 31689688 DOI: 10.1088/1361-648x/ab5488] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The field of magnetic skyrmions has been actively investigated across a wide range of topics during the last decades. In this topical review, we mainly review and discuss key results and findings in skyrmion research 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.
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Affiliation(s)
- Xichao Zhang
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, People's Republic of China
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41
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Yan H, Feng Z, Qin P, Zhou X, Guo H, Wang X, Chen H, Zhang X, Wu H, Jiang C, Liu Z. Electric-Field-Controlled Antiferromagnetic Spintronic Devices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1905603. [PMID: 32048366 DOI: 10.1002/adma.201905603] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 11/21/2019] [Indexed: 06/10/2023]
Abstract
In recent years, the field of antiferromagnetic spintronics has been substantially advanced. Electric-field control is a promising approach for achieving ultralow power spintronic devices via suppressing Joule heating. Here, cutting-edge research, including electric-field modulation of antiferromagnetic spintronic devices using strain, ionic liquids, dielectric materials, and electrochemical ionic migration, is comprehensively reviewed. Various emergent topics such as the Néel spin-orbit torque, chiral spintronics, topological antiferromagnetic spintronics, anisotropic magnetoresistance, memory devices, 2D magnetism, and magneto-ionic modulation with respect to antiferromagnets are examined. In conclusion, the possibility of realizing high-quality room-temperature antiferromagnetic tunnel junctions, antiferromagnetic spin logic devices, and artificial antiferromagnetic neurons is highlighted. It is expected that this work provides an appropriate and forward-looking perspective that will promote the rapid development of this field.
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Affiliation(s)
- Han Yan
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Zexin Feng
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Peixin Qin
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Xiaorong Zhou
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Huixin Guo
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Xiaoning Wang
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Hongyu Chen
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Xin Zhang
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Haojiang Wu
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Chengbao Jiang
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Zhiqi Liu
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
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42
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Han MG, Garlow JA, Liu Y, Zhang H, Li J, DiMarzio D, Knight MW, Petrovic C, Jariwala D, Zhu Y. Topological Magnetic-Spin Textures in Two-Dimensional van der Waals Cr 2Ge 2Te 6. NANO LETTERS 2019; 19:7859-7865. [PMID: 31661617 DOI: 10.1021/acs.nanolett.9b02849] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Two-dimensional (2D) van der Waals (vdW) materials show a range of profound physical properties that can be tailored through their incorporation in heterostructures and manipulated with external forces. The recent discovery of long-range ferromagnetic order down to atomic layers provides an additional degree of freedom in engineering 2D materials and their heterostructure devices for spintronics, valleytronics, and magnetic tunnel junction switches. Here, using direct imaging by cryo-Lorentz transmission electron microscopy we show that topologically nontrivial magnetic-spin states, skyrmionic bubbles, can be realized in exfoliated insulating 2D vdW Cr2Ge2Te6. Due to the competition between dipolar interactions and uniaxial magnetic anisotropy, hexagonally packed nanoscale bubble lattices emerge by field cooling with magnetic field applied along the out-of-plane direction. Despite a range of topological spin textures in stripe domains arising due to pair formation and annihilation of Bloch lines, bubble lattices with single chirality are prevalent. Our observation of topologically nontrivial homochiral skyrmionic bubbles in exfoliated vdW materials provides a new avenue for novel quantum states in atomically thin insulators for magneto-electronic and quantum devices.
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Affiliation(s)
- Myung-Geun Han
- Condensed Matter Physics and Materials Science , Brookhaven National Laboratory , Upton , New York 11973 , United States
| | - Joseph A Garlow
- Condensed Matter Physics and Materials Science , Brookhaven National Laboratory , Upton , New York 11973 , United States
- Department of Materials Science and Chemical Engineering , Stony Brook University , Stony Brook , New York 11794 , United States
| | - Yu Liu
- Condensed Matter Physics and Materials Science , Brookhaven National Laboratory , Upton , New York 11973 , United States
| | - Huiqin Zhang
- Department of Electrical and Systems Engineering , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
| | - Jun Li
- Condensed Matter Physics and Materials Science , Brookhaven National Laboratory , Upton , New York 11973 , United States
| | - Donald DiMarzio
- NG Next , Northrop Grumman Corporation , Redondo Beach , California 90278 , United States
| | - Mark W Knight
- NG Next , Northrop Grumman Corporation , Redondo Beach , California 90278 , United States
| | - Cedomir Petrovic
- Condensed Matter Physics and Materials Science , Brookhaven National Laboratory , Upton , New York 11973 , United States
| | - Deep Jariwala
- Department of Electrical and Systems Engineering , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
| | - Yimei Zhu
- Condensed Matter Physics and Materials Science , Brookhaven National Laboratory , Upton , New York 11973 , United States
- Department of Materials Science and Chemical Engineering , Stony Brook University , Stony Brook , New York 11794 , United States
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43
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Chen W, Tao Z, Zhao R, Zhang X. Regulating the magnetic skyrmion in a confined nanochannel under a gradient magnetic field. NANOTECHNOLOGY 2019; 30:415401. [PMID: 31295727 DOI: 10.1088/1361-6528/ab3145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A magnetic skyrmion could be endowed with various dynamic magnetic configurations and behaviors. By artificially generating a gradient magnetic field in a confined nanochannel, we have shown the magnetic dynamics of an isolated skyrmion, achieving the coexistence of moving and breathing modes. Such a phenomenon has been proven to be not only correlated to the gradient strength of a magnetic field, but also depends on the Dzyaloshinskii-Moriya interaction. By increasing the magnetic field gradient up to 0.1 mT nm-1, the skyrmion can effectively overcome the skyrmion Hall effect, and meanwhile generate a breathing mode during the motion process under MFG = 1.0 mT nm-1 and DMI = 2.8 mJ m-3. The present study could provide an alternative approach to regulate the skyrmion at micro/nanoscales by using a gradient magnetic field.
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Affiliation(s)
- Wenchao Chen
- Institute of Advanced Magnetic Materials, Hangzhou Dianzi University, Hangzhou 310012, People's Republic of China
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44
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Passian A, Imam N. Nanosystems, Edge Computing, and the Next Generation Computing Systems. SENSORS (BASEL, SWITZERLAND) 2019; 19:E4048. [PMID: 31546907 PMCID: PMC6767340 DOI: 10.3390/s19184048] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 09/11/2019] [Accepted: 09/16/2019] [Indexed: 12/24/2022]
Abstract
It is widely recognized that nanoscience and nanotechnology and their subfields, such as nanophotonics, nanoelectronics, and nanomechanics, have had a tremendous impact on recent advances in sensing, imaging, and communication, with notable developments, including novel transistors and processor architectures. For example, in addition to being supremely fast, optical and photonic components and devices are capable of operating across multiple orders of magnitude length, power, and spectral scales, encompassing the range from macroscopic device sizes and kW energies to atomic domains and single-photon energies. The extreme versatility of the associated electromagnetic phenomena and applications, both classical and quantum, are therefore highly appealing to the rapidly evolving computing and communication realms, where innovations in both hardware and software are necessary to meet the growing speed and memory requirements. Development of all-optical components, photonic chips, interconnects, and processors will bring the speed of light, photon coherence properties, field confinement and enhancement, information-carrying capacity, and the broad spectrum of light into the high-performance computing, the internet of things, and industries related to cloud, fog, and recently edge computing. Conversely, owing to their extraordinary properties, 0D, 1D, and 2D materials are being explored as a physical basis for the next generation of logic components and processors. Carbon nanotubes, for example, have been recently used to create a new processor beyond proof of principle. These developments, in conjunction with neuromorphic and quantum computing, are envisioned to maintain the growth of computing power beyond the projected plateau for silicon technology. We survey the qualitative figures of merit of technologies of current interest for the next generation computing with an emphasis on edge computing.
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Affiliation(s)
- Ali Passian
- Computing & Computational Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA.
| | - Neena Imam
- Computing & Computational Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA.
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45
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Wang K, Qian L, Ying SC, Xiao G, Wu X. Controlled modification of skyrmion information in a three-terminal racetrack memory. NANOSCALE 2019; 11:6952-6961. [PMID: 30916055 DOI: 10.1039/c9nr00909d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Manipulation of magnetic skyrmions has been generating considerable interest because of their potential applications in future spintronic devices. As an information carrier, a skyrmion is used to code a bit. In this work, we study via micromagnetic simulations a three-terminal racetrack memory, where an isolated skyrmion can be generated and annihilated by the gate voltage pulse. Thus, we can modify a train of skyrmion codes written at the generator in a controlled manner. The modified information is then detected at the collector. We have identified both gyration and breathing modes during skyrmion manipulation. The dynamics is analysed via a Thiele equation derived from the micromagnetic model. From the equation, the gyration mode of a skyrmion is suggested to be coupled to the breathing mode dynamics. This work proposes an effective method for controlled modification of skyrmion information in a potential energy-efficient racetrack memory, and provides a fundamental understanding of the intrinsic skyrmion dynamics during skyrmion manipulation.
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Affiliation(s)
- Kang Wang
- Collaborative Innovation Center of Advanced Microstructures, Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing 210093, China.
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Abstract
The next-generation logic and memory devices using magnetic skyrmions as spintronic information carriers are frequently studied, thanks to their remarkable magnetic stability, extremely compact size and very-low-cost driving forces within nanotracks. In order to realize skyrmion-based spintronic devices, understanding the skyrmion generation and their dynamics are essential. In this study, we have carried out a systematic micromagnetic simulation study on coherent magnetic skyrmion generation in which we theoretically engineered nanotracks by embedding an anti-notch to a channel of certain width. We found that the drift velocity and the skyrmion generation frequency can be tailored by the applied spin-polarized DC current density. Moreover, skyrmion generation is crucially affected by both damping and nonadiabaticity parameters, as well as the geometry of the anti-notch. We anticipate that our predictions provide rational basis for skyrmion-based devices in which skyrmions are used as information carriers, and influence future discussions.
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47
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Zhang X, Cai W, Zhang X, Wang Z, Li Z, Zhang Y, Cao K, Lei N, Kang W, Zhang Y, Yu H, Zhou Y, Zhao W. Skyrmions in Magnetic Tunnel Junctions. ACS APPLIED MATERIALS & INTERFACES 2018; 10:16887-16892. [PMID: 29682962 DOI: 10.1021/acsami.8b03812] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In this work, we demonstrate that skyrmions can be nucleated in the free layer of a magnetic tunnel junction (MTJ) with Dzyaloshinskii-Moriya interactions (DMIs) by a spin-polarized current with the assistance of stray fields from the pinned layer. The size, stability, and number of created skyrmions can be tuned by either the DMI strength or the stray field distribution. The interaction between the stray field and the DMI effective field is discussed. A device with multilevel tunneling magnetoresistance is proposed, which could pave the ways for skyrmion-MTJ-based multibit storage and artificial neural network computation. Our results may facilitate the efficient nucleation and electrical detection of skyrmions.
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Affiliation(s)
- Xueying Zhang
- Fert Beijing Institute, BDBC, School of Electronic and Information Engineering , Beihang University , Beijing 100191 , China
- Beihang-Goertek Joint Microelectronics Institute, Qingdao Research Institute , Beihang University , Qingdao 266101 , China
| | - Wenlong Cai
- Fert Beijing Institute, BDBC, School of Electronic and Information Engineering , Beihang University , Beijing 100191 , China
| | - Xichao Zhang
- School of Science and Engineering , The Chinese University of Hong Kong , Shenzhen 518172 , China
| | - Zilu Wang
- Fert Beijing Institute, BDBC, School of Electronic and Information Engineering , Beihang University , Beijing 100191 , China
| | - Zhi Li
- Fert Beijing Institute, BDBC, School of Electronic and Information Engineering , Beihang University , Beijing 100191 , China
- Beihang-Goertek Joint Microelectronics Institute, Qingdao Research Institute , Beihang University , Qingdao 266101 , China
| | - Yu Zhang
- Fert Beijing Institute, BDBC, School of Electronic and Information Engineering , Beihang University , Beijing 100191 , China
| | - Kaihua Cao
- Fert Beijing Institute, BDBC, School of Electronic and Information Engineering , Beihang University , Beijing 100191 , China
| | - Na Lei
- Fert Beijing Institute, BDBC, School of Electronic and Information Engineering , Beihang University , Beijing 100191 , China
- Beihang-Goertek Joint Microelectronics Institute, Qingdao Research Institute , Beihang University , Qingdao 266101 , China
| | - Wang Kang
- Fert Beijing Institute, BDBC, School of Electronic and Information Engineering , Beihang University , Beijing 100191 , China
| | - Yue Zhang
- Fert Beijing Institute, BDBC, School of Electronic and Information Engineering , Beihang University , Beijing 100191 , China
| | - Haiming Yu
- Fert Beijing Institute, BDBC, School of Electronic and Information Engineering , Beihang University , Beijing 100191 , China
| | - Yan Zhou
- School of Science and Engineering , The Chinese University of Hong Kong , Shenzhen 518172 , China
| | - Weisheng Zhao
- Fert Beijing Institute, BDBC, School of Electronic and Information Engineering , Beihang University , Beijing 100191 , China
- Beihang-Goertek Joint Microelectronics Institute, Qingdao Research Institute , Beihang University , Qingdao 266101 , China
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48
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Ho LDA, Tran MT, Cao XH, Dao VA, Ngo DT, Hoang DQ. Field-driven single domain wall motion in ferromagnetic nanowires. RSC Adv 2018; 8:14539-14551. [PMID: 35540750 PMCID: PMC9079939 DOI: 10.1039/c8ra01597j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 04/09/2018] [Indexed: 11/21/2022] Open
Abstract
We present a Lorentz microscopy study of polycrystalline permalloy 2D nanostructures with a thickness of 20 nm. Each structure was designed as a single domain wall trap. The trap comprises two horizontal nanowires with an in-plane dimension of 200 × 1000 nm2, and three tilted pads with different shapes. These structures allow us to create head-to-head domain walls, and these created walls can propagate in the structures by an external magnetic field. These designed traps were simulated using the micro-magnetic OOMMF simulation software. Those nanostructures were also patterned using electron beam lithography and focussed-ion beam techniques. This aims to determine the geometric parameters required to propagate a single magnetic domain wall in these structures reproducibly. Among the studied structures with one and two field directions, we found that the motion of a domain wall can be reproducibly driven by two alternative field directions in a trap which consists of the two horizontal nanowires and three 90°-tilted ones. We investigated systematically the viability of both single field and sequential switching of two field directions. Lorentz microscopy and micro-magnetic simulation results indicate that the propagation of a domain wall is strongly affected by the precise shape of the corner sections linking the trap elements, and the angles of the horizontal nanowires and tilted pads. Domain wall pinning and transformation of wall chirality are strongly correlated to the trap geometries. Our results are vital to design an optimal trap which supports a reproducible domain wall motion. This might also support a greater understanding of domain wall creation and propagation in magnetic nanowires which are of interest for concepts of high-density and ultrafast nonvolatile data storage devices, including racetrack memory and magnetic logic gates. A domain wall trap structure was found which is suitable for the field-driven single DW propagation between two narrow nanowires.![]()
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Affiliation(s)
- L. D. Anh Ho
- Sustainable Developments in Civil Engineering Research Group
- Faculty of Civil Engineering
- Ton Duc Thang University
- Ho Chi Minh City 700000
- Vietnam
| | - Minh-Tung Tran
- Sustainable Developments in Civil Engineering Research Group
- Faculty of Civil Engineering
- Ton Duc Thang University
- Ho Chi Minh City 700000
- Vietnam
| | - Xuan-Huu Cao
- Advanced Program in Electronics & Communication Engineering
- Da Nang University of Science and Technology
- Da Nang
- Vietnam
| | - Vinh-Ai Dao
- Department of Materials Technology
- Faculty of Applied Sciences
- Ho Chi Minh City University of Technology and Education
- Ho Chi Minh City 700000
- Vietnam
| | - Duc-The Ngo
- Electron Microscopy Centre
- School of Materials
- University of Manchester
- Manchester M13 9PL
- UK
| | - Duc-Quang Hoang
- Sustainable Developments in Civil Engineering Research Group
- Faculty of Civil Engineering
- Ton Duc Thang University
- Ho Chi Minh City 700000
- Vietnam
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49
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Nhut-Minh Ho V, Duc-Anh Ho L, Tran MT, Cao XH, Dao VA, Tong DH, Ngo DT, Hoang DQ. Exploring characteristics of the corner sections of a domain wall trap nanostructure with the two-field direction method. RSC Adv 2018; 8:41828-41835. [PMID: 35558803 PMCID: PMC9091946 DOI: 10.1039/c8ra08528e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 12/04/2018] [Indexed: 11/23/2022] Open
Abstract
A 2D polycrystalline permalloy domain wall trap nanostructure with a thickness of 20 nm was studied. The structure was alternatively designed and patterned using QCAD/L-Edit software and focused-ion beam technique. With this design, a magnetic domain wall can be created and propagated with a sequence of two-field directions in a Lorentz microscopy. The trap consists of two horizontal nanowires and three 90°-tilted ones. Each nanowire has an in-plane dimension of 200 × 1000 nm2. The trap corners were curved to allow a created domain wall that easily moves through the structure. A head-to-head domain-wall aims to create using a continuous field, this created wall can be propagated in the trap using a sequence of two-field directions. The designed trap was simulated using the Object Oriented Micro-Magnetic Framework software. Lorentz microscopy and simulation results indicate that the propagation of a domain wall is strongly affected by the precise roughness behavior of the trap elements. Domain wall pinning and transformation of wall chirality are sensitively correlated to the corner sections of the trap structure and field directions at a certain regime. Using the two-field direction method enables us to explore characteristics of the corner sections of the patterned trap nanostructure. This study is vital to fabricate an optimal nano-trap which supports a reproducible domain wall motion. This also suggests a useful method for the domain wall propagation using sequences of two-field directions. This work provides a better understanding of wall creation and propagation in polycrystalline permalloy curved nanowires which are of interest for concepts of nonvolatile data storage devices. A domain wall trap structure which supports a reproducible wall motion using the two field direction method with variations of the two field orientation angles (±θ).![]()
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Affiliation(s)
- Vu Nhut-Minh Ho
- Applied Computational Civil and Structural Engineering Research Group
- Faculty of Civil Engineering
- Ton Duc Thang University
- Ho Chi Minh City 700000
- Vietnam
| | - Le Duc-Anh Ho
- Faculty of Applied Sciences
- Ton Duc Thang University
- Ho Chi Minh City 700000
- Vietnam
| | - Minh-Tung Tran
- Faculty of Civil Engineering
- Ton Duc Thang University
- Ho Chi Minh City 700000
- Vietnam
| | - Xuan-Huu Cao
- Advanced Program in Electronics & Communication Engineering
- Da Nang University of Science and Technology
- Da Nang 550000
- Vietnam
| | - Vinh-Ai Dao
- Future Materials & Devices Laboratory
- Institute for Fundamental and Applied Sciences
- Duy Tan University
- Ho Chi Minh City 700000
- Vietnam
| | - Duy-Hien Tong
- Institute for Computational Science
- Ton Duc Thang University
- Ho Chi Minh City 700000
- Vietnam
| | - Duc-The Ngo
- Electron Microscopy Centre
- School of Materials
- University of Manchester
- Manchester M13 9PL
- UK
| | - Duc-Quang Hoang
- Applied Computational Civil and Structural Engineering Research Group
- Faculty of Civil Engineering
- Ton Duc Thang University
- Ho Chi Minh City 700000
- Vietnam
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