User-centric data sharing is essential to encourage citizens'active participation in the digital economy.One key to smart cities,a form of the digital economy,is the promotion of public use of citizen data.Neverth...User-centric data sharing is essential to encourage citizens'active participation in the digital economy.One key to smart cities,a form of the digital economy,is the promotion of public use of citizen data.Nevertheless,it is not easy to utilize data without citizens’consent.In this study,we took a technological approach to these issues.Usermanaged access(UMA)is a well-known framework for delegating resource access rights to others on the Internet.In UMA,authorization mechanisms are designed to be centralized so that resource owners can centrally manage access rights for various resources stored in different domains.However,the lack of transparency in the authorization mechanism is a barrier to its implementation in large-scale systems such as smart cities.In this study,we developed a blockchain-based cross-domain authorization architecture that enables a resource-sharing ecosystem in which organizations that wish to utilize data can freely trade with each other.The proposed architecture solves the transparency problem that conventional authorization systems have had by designing the authorization mechanism on blockchain technology.We implemented the proposed architecture as smart contracts and evaluated its processing performance.The resultant time required for delegating access rights and accessing resources was less than 500 ms.Furthermore,we found that the fluctuation in the processing time overhead was small.Based on these results,we concluded that performance degradation with the proposed architecture is minor.展开更多
Skyrmion-based devices are promising candi-dates for non-volatile memory and low-delay time com-putation.Many skyrmion-based devices execute operation by controlling skyrmion trajectory,which can be impeded by the sky...Skyrmion-based devices are promising candi-dates for non-volatile memory and low-delay time com-putation.Many skyrmion-based devices execute operation by controlling skyrmion trajectory,which can be impeded by the skyrmion Hall effect.Here,the design of skyrmion-based arithmetic devices built on synthetic antiferromag-netic(SyAF)structures is presented,where the structure can greatly suppress skyrmion Hall effect.In this study,the operations of skyrmion-based half adder,full adder,and XOR logic gate are executed by introducing geometric notches and tilted edges,which can annihilate or diverge skyrmion.Performance of these skyrmion-based devices is evaluated,where the delay time and energy-delay product of the single-bit full adder are 1.95 ns and 2.50×10^(-22)Js,which are only 12%and 79%those of the previously proposed skyrmion-based single-bit full adder.This improvement is significant in the construction of ripple-carry adder and ripple-carry adder-subtractor.Therefore,our skyrmion-based SyAF arithmetic device is a promising candidate to develop high-speed spintronic devices.展开更多
A magnetic bimeron is an in-plane topological counterpart of a magnetic skyrmion.Despite the topological equivalence,their statics and dynamics could be distinct,making them attractive from the perspectives of both ph...A magnetic bimeron is an in-plane topological counterpart of a magnetic skyrmion.Despite the topological equivalence,their statics and dynamics could be distinct,making them attractive from the perspectives of both physics and spintronic applications.In this work,we demonstrate the stabilization of bimeron solitons and clusters in the antiferromagnetic(AFM)thin film with interfacial Dzyaloshinskii–Moriya interaction(DMI).Bimerons demonstrate high current-driven mobility as generic AFM solitons,while featuring anisotropic and relativistic dynamics excited by currents with in-plane and out-ofplane polarizations,respectively.Moreover,these spin textures can absorb other bimeron solitons or clusters along the translational direction to acquire a wide range of Néel topological numbers.The clustering involves the rearrangement of topological structures,and gives rise to remarkable changes in static and dynamical properties.The merits of AFM bimeron clusters reveal a potential path to unify multibit data creation,transmission,storage,and even topology-based computation within the same material system,and may stimulate spintronic devices enabling innovative paradigms of data manipulations.展开更多
基金supported by JSPS KAKENHI(Grant Number JP19K11963,JP22K17881,JP18K04133,and JP22H00550).
文摘User-centric data sharing is essential to encourage citizens'active participation in the digital economy.One key to smart cities,a form of the digital economy,is the promotion of public use of citizen data.Nevertheless,it is not easy to utilize data without citizens’consent.In this study,we took a technological approach to these issues.Usermanaged access(UMA)is a well-known framework for delegating resource access rights to others on the Internet.In UMA,authorization mechanisms are designed to be centralized so that resource owners can centrally manage access rights for various resources stored in different domains.However,the lack of transparency in the authorization mechanism is a barrier to its implementation in large-scale systems such as smart cities.In this study,we developed a blockchain-based cross-domain authorization architecture that enables a resource-sharing ecosystem in which organizations that wish to utilize data can freely trade with each other.The proposed architecture solves the transparency problem that conventional authorization systems have had by designing the authorization mechanism on blockchain technology.We implemented the proposed architecture as smart contracts and evaluated its processing performance.The resultant time required for delegating access rights and accessing resources was less than 500 ms.Furthermore,we found that the fluctuation in the processing time overhead was small.Based on these results,we concluded that performance degradation with the proposed architecture is minor.
基金financially supported by Shenzhen Fundamental Research Fund (No. JCYJ20210324120213037)Guangdong Special Support Project (No. 2019BT02X030)+8 种基金Shenzhen Peacock Group Plan (No. KQTD20180413181702403)Pearl River Recruitment Program of Talents (No. 2017GC010293)the National Natural Science Foundation of China (Nos. 11974298 and 61961136006)International Research Fellow of Japan Society for the Promotion of Science (JSPS), was supported by JSPS KAKENHI (No. JP20F20363)the support by the Grants-in-Aid for Scientific Research from JSPS KAKENHI (Nos. JP18H03676 and JP17K05490)the support by Core Research for Evolutionary Science and Technology, Japan Science and Technology Agency (Nos. JPMJCR20T2 and JPMJCR16F1)the support by the Grants-in-Aid for Scientific Research from JSPS KAKENHI (Nos. JP20F20363 and JP21H01364)the support by the National Natural Science Foundation of China (No. 12104327)the funding from the European Union’s Framework Program for Research and Innovation Horizon 2020 (No. 2014-2020) under the Marie Sk?odowska-Curie Grant Agreement No. 860060 (ITN MagnEFi)
文摘Skyrmion-based devices are promising candi-dates for non-volatile memory and low-delay time com-putation.Many skyrmion-based devices execute operation by controlling skyrmion trajectory,which can be impeded by the skyrmion Hall effect.Here,the design of skyrmion-based arithmetic devices built on synthetic antiferromag-netic(SyAF)structures is presented,where the structure can greatly suppress skyrmion Hall effect.In this study,the operations of skyrmion-based half adder,full adder,and XOR logic gate are executed by introducing geometric notches and tilted edges,which can annihilate or diverge skyrmion.Performance of these skyrmion-based devices is evaluated,where the delay time and energy-delay product of the single-bit full adder are 1.95 ns and 2.50×10^(-22)Js,which are only 12%and 79%those of the previously proposed skyrmion-based single-bit full adder.This improvement is significant in the construction of ripple-carry adder and ripple-carry adder-subtractor.Therefore,our skyrmion-based SyAF arithmetic device is a promising candidate to develop high-speed spintronic devices.
基金X.L.acknowledges the support by the Guangdong Basic and Applied Basic Research Foundation(Grant No.2019A1515111110)X.Z.acknowledges the support by the National Natural Science Foundation of China(Grant No.12004320)+15 种基金the Guangdong Basic and Applied Basic Research Foundation(Grant No.2019A1515110713)Presidential Postdoctoral Fellowship of The Chinese University of Hong Kong,Shenzhen(CUHKSZ)M.E.acknowledges the support from the Grants-in-Aid for Scientific Research from JSPS KAKENHI(Grant Nos.JP18H03676,JP17K05490,and JP15H05854)the support from CREST,JST(Grant Nos.JPMJCR16F1 and JPMJCR1874)O.A.T.acknowledges the support by the Australian Research Council(Grant No.DP200101027)the Cooperative Research Project Program at the Research Institute of Electrical Communication,Tohoku University(Japan),and by the Ministry of Science and Technology Higher Education of the Russian Federation in the framework of Increase Competitiveness Program of NUST“MISiS”(No.K2-2019-006)implemented by a governmental decree dated 16th of March 2013,N 211.X.X.acknowledges the support from the National Natural Science Foundation of China(51871137 and 61434002)the National Key R&D Program of China(2017YFB0405604)M.M.and M.K.acknowledge support from National Science Center of Poland No.2018/30/Q/ST3/00416Y.Z.acknowledges the support by the President’s Fund of CUHKSZ,Longgang Key Laboratory of Applied Spintronics,National Natural Science Foundation of China(Grant Nos.11974298 and 61961136006)Shenzhen Fundamental Research Fund(Grant No.JCYJ20170410171958839)Shenzhen Peacock Group Plan(Grant No.KQTD20180413181702403)Y.X.acknowledges the support by the State Key Program for Basic Research of China(Grant No.2014CB921101,2016YFA0300803)NSFC(Grants No.61427812,11574137)Jiangsu NSF(BK20140054)Jiangsu Shuangchuang Team Program and the UK EPSRC(EP/G010064/1).
文摘A magnetic bimeron is an in-plane topological counterpart of a magnetic skyrmion.Despite the topological equivalence,their statics and dynamics could be distinct,making them attractive from the perspectives of both physics and spintronic applications.In this work,we demonstrate the stabilization of bimeron solitons and clusters in the antiferromagnetic(AFM)thin film with interfacial Dzyaloshinskii–Moriya interaction(DMI).Bimerons demonstrate high current-driven mobility as generic AFM solitons,while featuring anisotropic and relativistic dynamics excited by currents with in-plane and out-ofplane polarizations,respectively.Moreover,these spin textures can absorb other bimeron solitons or clusters along the translational direction to acquire a wide range of Néel topological numbers.The clustering involves the rearrangement of topological structures,and gives rise to remarkable changes in static and dynamical properties.The merits of AFM bimeron clusters reveal a potential path to unify multibit data creation,transmission,storage,and even topology-based computation within the same material system,and may stimulate spintronic devices enabling innovative paradigms of data manipulations.
