With the cross-fertilization of artificial intelligence(AI)technology and spintronics,the traditional AI teaching system has revealed its limitations in terms of industrial adaptability and interdisciplinary integrati...With the cross-fertilization of artificial intelligence(AI)technology and spintronics,the traditional AI teaching system has revealed its limitations in terms of industrial adaptability and interdisciplinary integration.In order to cope with this challenge,this study takes Introduction to Artificial Intelligence as the basis,and proposes a conceptual framework of“technical-legal”double helix teaching model,aiming at reconstructing the existing curriculum through three-dimensional teaching design innovation:(1)In the technical level,adding the cutting-edge topic of“Spintronics and Neuromorphic Computing,”through simulation and literature study,students are guided to explore the principle of brain-like computation based on STT-MRAM;(2)at the legal level,the teaching paradigm of“integrating the awareness of legal compliance into technological research and development”is constructed,and it is planned to develop a library of legal science and technology seminars containing cases such as analysis of intelligent contracts;(3)at the practical level,the establishment of an“industry-academia-research”program is explored and improve the comprehensive practical ability of students by simulating the cooperation projects between schools and enterprises.The expected goal of this teaching reform program is to enhance students’technological innovation thinking and legal risk prevention awareness,and to provide a teaching reform idea with reference value for exploring the cultivation path of“AI+Law”composite talents.展开更多
The outcomes of computational study of electronic, magnetic and optical spectra for A2BX6 (A = Rb;B = Tc, Pb, Pt, Sn, W, Ir, Ta, Sb, Te, Se, Mo, Mn, Ti, Zr and X = Cl, Br) materials have been proceeded utilizing Vande...The outcomes of computational study of electronic, magnetic and optical spectra for A2BX6 (A = Rb;B = Tc, Pb, Pt, Sn, W, Ir, Ta, Sb, Te, Se, Mo, Mn, Ti, Zr and X = Cl, Br) materials have been proceeded utilizing Vanderbilt Ultra Soft Pseudo Potential (US-PP) process. The Rb2PbBr6 and Rb2PbCl6 are found to be a (Г-Г) semiconductors with energy gaps of 0.275 and 1.142 eV, respectively making them promising photovoltaic materials. The metallic behavior of the materials for Rb2BX6 (B = Tc, W, Ir, Ta, Mn, Sb, Mo) has been confirmed showing the attendance of conducting lineaments. The dielectric function is found to be large close to the ultraviolet districts (3.10 - 4.13 eV). The extinction coefficient of the Rb2BX6 has the ability to be used for implements. The band structures and density of states ensure the magnetic semiconductors’ nature of the Rb2Mn (Cl, Br)6 perovskites. The total calculated magnetic moment of Rb2MnCl6 and Rb2MnB6 is 3.00μβ. Advanced spintronic technology requires room-temperature ferromagnetism. The present work confirms that, bromine and chlorine-founded double perovskites are extremely attractive for photovoltaic and optoelectronic devices.展开更多
Spintronics,exploiting the spin degree of electrons as the information vector,is an attractive field for implementing the beyond Complemetary metal-oxide-semiconductor(CMOS)devices.Recently,two-dimensional(2D)material...Spintronics,exploiting the spin degree of electrons as the information vector,is an attractive field for implementing the beyond Complemetary metal-oxide-semiconductor(CMOS)devices.Recently,two-dimensional(2D)materials have been drawing tremendous attention in spintronics owing to their distinctive spin-dependent properties,such as the ultralong spin relaxation time of graphene and the spin-valley locking of transition metal dichalcogenides.Moreover,the related heterostructures provide an unprecedented probability of combining the di erent characteristics via proximity e ect,which could remedy the limitation of individual 2D materials.Hence,the proximity engineering has been growing extremely fast and has made significant achievements in the spin injection and manipulation.Nevertheless,there are still challenges toward practical application;for example,the mechanism of spin relaxation in 2D materials is unclear,and the high-effciency spin gating is not yet achieved.In this review,we focus on 2D materials and related heterostructures to systematically summarize the progress of the spin injection,transport,manipulation,and application for information storage and processing.We also highlight the current challenges and future perspectives on the studies of spintronic devices based on 2D materials.展开更多
Our world is composed of various materials with different structures,where spin structures have been playing a pivotal role in spintronic devices of the contemporary information technology.Apart from conventional coll...Our world is composed of various materials with different structures,where spin structures have been playing a pivotal role in spintronic devices of the contemporary information technology.Apart from conventional collinear spin materials such as collinear ferromagnets and collinear antiferromagnetic ally coupled materials,noncollinear spintronic materials have emerged as hot spots of research attention due to exotic physical phenomena.In this review,we first introduce two types of noncollinear spin structures,i.e.,the chiral spin structure that yields real-space Berry phases and the coplanar noncollinear spin structure that could generate momentum-space Berry phases,and then move to relevant novel physical phenomena including topological Hall effect,anomalous Hall effect,multiferroic,Weyl fermions,spin-polarized current and spin Hall effect without spin-orbit coupling in these noncollinear spin systems.Afterward,we summarize and elaborate the electric-field control of the noncollinear spin structure and related physical effects,which could enable ultralow power spintronic devices in future.In the final outlook part,we emphasize the importance and possible routes for experimentally detecting the intriguing theoretically predicted spin-polarized current,verifying the spin Hall effect in the absence of spin-orbit coupling and exploring the anisotropic magnetoresistance and domain-wall-related magnetoresistance effects for noncollinear antiferromagnetic materials.展开更多
Magnetic orderings, i.e., the spontaneous alignment of electron spins below a critical temperature, have been playing key roles in modern science and technologies for both the wide applications of magnetic recording f...Magnetic orderings, i.e., the spontaneous alignment of electron spins below a critical temperature, have been playing key roles in modern science and technologies for both the wide applications of magnetic recording for information storage and the vibrant potential of solid state electronic spin devices (also known as spintronics) for logic operations. In the past decades, thanks to the development of thin film technologies, magnetic thin films via sputtering or epitaxial growth have made the spintronic devices possible at the industrial scale. Yet thinner materials at lower costs with more versatile functionalities are highly desirable for advancing future spintronics. Recently, van der Waals magnetic materials, a family of magnets that can in principle be exfoliated down to the monolayer limit, seem to have brought tremendous opportunities: new generation van der Waals spintronic devices can be seamlessly assembled with possible applications such as optoelectronics, flexible electronics, and etc. Moreover, those exfoliated spintronic devices can potentially be compatible with the famed metal-oxide field effect transistor architectures, allowing the harness of spin performances through the knob of an electrostatic field.展开更多
Neuromorphic computing is the development of computingschemes inspired by the processing of information in thebrain, which can execute complex tasks very efficiently usingan architecture that is completely different f...Neuromorphic computing is the development of computingschemes inspired by the processing of information in thebrain, which can execute complex tasks very efficiently usingan architecture that is completely different from that of semiconductorchips. Recently, researchers from Tohoku Universityhave realized an artificial neuron and synapse in spintronicsdevices, which are promising for future energy-efficientand adoptive computing systems, as they behave likethe spiking neural network in human brains.展开更多
Spintronics involves the study of active control and manipulation of spin degrees of freedom in solid-state systems. The fascinating spin-resolved properties of graphene motivate numerous researchers to study spintron...Spintronics involves the study of active control and manipulation of spin degrees of freedom in solid-state systems. The fascinating spin-resolved properties of graphene motivate numerous researchers to study spintronics in graphene and other two-dimensional(2D) materials. Silicene, the silicon analog of graphene, is considered to be a promising material for spintronics. Here, we present a review of theoretical advances with regard to spin-dependent properties, including the electric field- and exchange field-tunable topological properties of silicene and the corresponding spintronic device simulations.展开更多
Since its discovery in early 2000’s Molecular Spintronics has developed in an established and fructuous research field,achieving a number of outstanding results and unveiling unusual spintronic properties.Typically t...Since its discovery in early 2000’s Molecular Spintronics has developed in an established and fructuous research field,achieving a number of outstanding results and unveiling unusual spintronic properties.Typically the most mysterious device element,the interface,in molecular spintronics has on contrary received and enormous attention and even gained a special nickname–the spinterface.Based on significant efforts of many research groups worldwide it has been established its critical role in defining the main functionalities of molecular spintronic devices.Noteworthily the spinterface was found to control the properties of the both components constituting the interface,not only those of the molecular layer but surprisingly also those of the magnetic counterpart.This paper aims to overview the most striking spinterface properties and to highlight the possibilities to promote new device paradigms based on interfacial modulation.展开更多
It is commonly known that the hydrodynamic equations can be derived from the Boltzmann equation. In this paper, we derive similar spin-dependent balance equations based on the spinor Boltzmann equation. Besides the us...It is commonly known that the hydrodynamic equations can be derived from the Boltzmann equation. In this paper, we derive similar spin-dependent balance equations based on the spinor Boltzmann equation. Besides the usual charge current, heat current, and pressure tensor, we also explore the characteristic spin accumulation and spin current as well as the spin-dependent pressure tensor and heat current in spintronics. The numerical results of these physical quantities are demonstrated using an example of spin-polarized transport through a mesoscopic ferromagnet.展开更多
Half metallic polycrystalline, epitaxial Fe3O4 films and Fe3O4 -based heterostructures for spintronics were fabricated by DC reactive magnetron sputtering. Large tunneling magnetoresistance was found in the polycrysta...Half metallic polycrystalline, epitaxial Fe3O4 films and Fe3O4 -based heterostructures for spintronics were fabricated by DC reactive magnetron sputtering. Large tunneling magnetoresistance was found in the polycrystalline Fe3O4 films and attributed to the insulating grain boundaries. The pinning effect of the moments at the grain boundaries leads to a significant exchange bias. Frozen interfacial/surface moments induce weak saturation of the high-field magnetoresistance. The films show a moment rotation related butterfly-shaped magnetoresistance. It was found that in the films, natural growth defects, antiphase boundaries, and magnetocrystalline anisotropy play important roles in high-order anisotropic magnetoresistance. Spin injection from Fe3O4 films to semiconductive Si and ZnO was measured to be 45% and 28.5%, respectively. The positive magnetoresistance in the Fe3O4 -based heterostructures is considered to be caused by a shift of the Fe3O4 e g ↑ band near the interface. Enhanced magnetization was observed in Fe3O4 /BiFeO 3 heterostructures experimentally and further proved by first principle calculations. The enhanced magnetization can be explained by spin moments of the thin BiFeO 3 layer substantially reversing into a ferromagnetic arrangement under a strong coupling that is principally induced by electronic orbital reconstruction at the interface.展开更多
Recent progress in organic spintronics is given an informative overview, covering spin injection, detection, and trans-port in organic spin valve devices, and the magnetic field effect in organic semiconductors （OSCs...Recent progress in organic spintronics is given an informative overview, covering spin injection, detection, and trans-port in organic spin valve devices, and the magnetic field effect in organic semiconductors （OSCs）. In particular, we focus on our own recent work in spin injection and the organic magnetic field effect （OMFE）.展开更多
Results of investigations of band structure, Fermi surface and effective masses of charge carriers in the ultrathin (monolayer graphene)/MnO(001) and MnO(001) films are presented using the method of the density functi...Results of investigations of band structure, Fermi surface and effective masses of charge carriers in the ultrathin (monolayer graphene)/MnO(001) and MnO(001) films are presented using the method of the density functional theory. Features of spin states of valence band and Fermi level as well as an interatomic interaction in these systems are discussed. A magnetic moment at Mn atom is estimated and an effect of spin polarization at atoms of oxygen and carbon has been revealed which natures are discussed. By calculations of structural energies for 2D (monolayer graphene)/MnO(001) and 2D MnO(001) a stability of these systems has been ascertained. In the 2D (monolayer graphene)/MnO(001) and 2D MnO(001) systems the band structure calculations for the 2D systems mentioned above point out that tensor components of effective masses of both electrons and holes are in the ranges of (0.15 - 0.54) m0 and (0.38 - 1.27) m0 respectively. Mobility estimations of two-dimensional charge carriers for a 2D (monolayer graphene)/MnO(001)AF2 heterostructure have been performed.展开更多
Molecular spintronics,as an emerging field that makes full use of the advantage of ultralong room-temperature spin lifetime and abundant electrical-optical-magnetic properties of molecular semiconductors,has gained wi...Molecular spintronics,as an emerging field that makes full use of the advantage of ultralong room-temperature spin lifetime and abundant electrical-optical-magnetic properties of molecular semiconductors,has gained wide attention for its great potential for further commercial applications.Despite the significant progress that has been made,there remain several huge challenges that limit the future development of this field.This Perspective provides discussions on the spin transport mechanisms and performances of molecular semiconductors,spinterface effect,and related spin injection in spintronic devices,and current spin-charge interactive functionalities,along with the summarization of the main obstacles of these aspects.Furthermore,we particularly propose targeted solutions,aiming to enhance the spin injection and transport efficiency by molecular design and interface engineering and explore diverse spinrelated functionalities.Through this Perspective,we hope it will help the spintronic community identify the research trends and accelerate the development of molecular spintronics.展开更多
Two-dimensional(2D)ferrovalley materials with valley-dependent Hall effect have attracted great interest due to their significant applications in spintronics.In this paper,by using first-principles computational simul...Two-dimensional(2D)ferrovalley materials with valley-dependent Hall effect have attracted great interest due to their significant applications in spintronics.In this paper,by using first-principles computational simulations,we predict that the ScBrCl monolayer is a 2D ferrovalley material with valley-dependent multiple Hall effects.After calculations,we found that the ScBrCl monolayer has excellent thermodynamic stability and kinetic stability,and has a high magnetic transition temperature.When the magnetization direction is turned from in-plane to out-of-plane,a large valley polarization of 44 meV can be generated.In particular,under 5.1%–5.3%tensile strain conditions,ScBrCl monolayer can achieve quantum anomalous Hall effect,and further prove its existence through non-zero Chern number and non-trivial edge state.Our discovery enriches the research on valley-dependent Hall effect and promotes the potential application of 2D Janus monolayer in valley electronics.展开更多
Topological insulators are emergent states of quantum matter that are gapped in the bulk with timereversal symmetry-pteserved gapless edge/surface states, adiabatically distinct from conventional mat erials. By proxim...Topological insulators are emergent states of quantum matter that are gapped in the bulk with timereversal symmetry-pteserved gapless edge/surface states, adiabatically distinct from conventional mat erials. By proximity to various magnets and superconductors, to pological insula tors show novel physics at the interfaces, which give rise to two new areas named topological spintronics and topological quantum compu tat ion. Effects in the former such as the spin to rques, spin-charge conversion, to pological antiferromagnetic spintronics, and skyrmions realized in topological systems will be addressed. In the latter, a superconducting pairing gap leads to a state that supports Majorana fermions states, which may provide a new path for realizing to pological quantum comp ut at ion. Various signa tu res of Majorana zero modes/edge mode in topological superconductors will be discussed. The review ends by outlooks and potential applications of topological insulators. Topological superconductors that are fabricated using topological insulators with superconductors have a full pairing gap in the bulk and gapless surface states consisting of Majorana fermions. The theory of topological superconductors is reviewed, in close analogy to the theory of topological insulators.展开更多
The unprecedented realization of two-dimensional(2D)van der Waals magnets excitingly extends the synergy between spintronics and 2D materials,started with graphene over the last decade.This article reviews the recent ...The unprecedented realization of two-dimensional(2D)van der Waals magnets excitingly extends the synergy between spintronics and 2D materials,started with graphene over the last decade.This article reviews the recent milestones in the development of 2D magnets and its derived heterostructures.In particular,a number of critical challenges centered around the scalability,ambient stability and Curie temperature of these atomically thin magnets are discussed.This mini-review also provides an outlook on what the future might hold for this integrated field of 2D spintronics,and assesses its potential in postsilicon electronics.展开更多
In spintronics, it is highly desirable to find new materials that can simultaneously possess complete spin-polarization, high-speed conduction electrons, large Curie temperature, and robust ferromagnetic ground states...In spintronics, it is highly desirable to find new materials that can simultaneously possess complete spin-polarization, high-speed conduction electrons, large Curie temperature, and robust ferromagnetic ground states. Using first-principles calculations, we demonstrate that the stable YN2 monolayer with octahedral coordination is a novel p-state Dirac half metal （DHM）, which not only has a fully spin-polarized Dirac state, but also the highest Fermi velocity （3.74×10^5 m/s） of the DHMs reported to date. In addition, its half-metallic gap of 1.53 eV is large enough to prevent the spin-flip transition. Because of the strong nonlocal p orbitals of N atoms （N-p） direct exchange interaction, the Curie temperature reaches over 332 K. Moreover, its ferromagnetic ground state can be well preserved under carrier doping or external strain. Therefore, the YN2 monolayer is a promising DHM for high-speed spintronic devices and would lead to new opportunities in designing other p-state DHMs.展开更多
We review the progress and future possibilities in the emerging area of molecular spintronics. We first provide an overview of the different transport regimes in which electronic nanodevices can operate, then briefly ...We review the progress and future possibilities in the emerging area of molecular spintronics. We first provide an overview of the different transport regimes in which electronic nanodevices can operate, then briefly overview the important characteristics of molecular magnetic materials that can be useful for application in spintronics and we eventually present several schemes to include such systems into spintronic nanodevices. We hightlight the importance of a chemical approach to the area, and in the last section we showcase some approaches to the creation of hybrids made of carbon nanostructures and molecular magnets, which are gaining increasing attention.展开更多
Over the pas few decades,the diversified development of antiferomagnetic spintronics has made antiferomagnets(AFMs)interesting and very useful.After tough challenges,the applications of AFMs in electronic devices have...Over the pas few decades,the diversified development of antiferomagnetic spintronics has made antiferomagnets(AFMs)interesting and very useful.After tough challenges,the applications of AFMs in electronic devices have transitioned from focusing on the interface coupling features to achieving the manipulation and detection of AFMs.As AFMs are internally magnetic,taking full use of AFMs for information storage has been the main target of research.In this paper,we provide a comprehensive description of AFM spintronics applications from the interface coupling,read-out operations,and writing manipulations perspective.We examine the early use of AFMs in magnetic recordings and conventional magnetoresistive random-access memory(MRAM),and review the latest mechanisms of the manipulation and detection of AFMs.Finally,based on exchange bias(EB)manipulation,a high-performance EB-MRAM is introduced as the next generation of AFM-based memories,which provides an effective method for read-out and writing of AFMs and opens a new era for AFM spintronics.展开更多
Carbon-based spintronics refers mainly to the spin injection and transport in carbon materials including carbon nanotubes,graphene,fullerene,and organic materials.In the last decade,extraordinary development has been ...Carbon-based spintronics refers mainly to the spin injection and transport in carbon materials including carbon nanotubes,graphene,fullerene,and organic materials.In the last decade,extraordinary development has been achieved for carbon-based spintronics,and the spin transport has been studied in both local and nonlocal spin valve devices.A series of theoretical and experimental studies have been done to reveal the spin relaxation mechanisms and spin transport properties in carbon materials,mostly for graphene and carbon nanotubes.In this article,we provide a brief review on spin injection and transport in graphene,carbon nanotubes,fullerene and organic thin films.展开更多
文摘With the cross-fertilization of artificial intelligence(AI)technology and spintronics,the traditional AI teaching system has revealed its limitations in terms of industrial adaptability and interdisciplinary integration.In order to cope with this challenge,this study takes Introduction to Artificial Intelligence as the basis,and proposes a conceptual framework of“technical-legal”double helix teaching model,aiming at reconstructing the existing curriculum through three-dimensional teaching design innovation:(1)In the technical level,adding the cutting-edge topic of“Spintronics and Neuromorphic Computing,”through simulation and literature study,students are guided to explore the principle of brain-like computation based on STT-MRAM;(2)at the legal level,the teaching paradigm of“integrating the awareness of legal compliance into technological research and development”is constructed,and it is planned to develop a library of legal science and technology seminars containing cases such as analysis of intelligent contracts;(3)at the practical level,the establishment of an“industry-academia-research”program is explored and improve the comprehensive practical ability of students by simulating the cooperation projects between schools and enterprises.The expected goal of this teaching reform program is to enhance students’technological innovation thinking and legal risk prevention awareness,and to provide a teaching reform idea with reference value for exploring the cultivation path of“AI+Law”composite talents.
文摘The outcomes of computational study of electronic, magnetic and optical spectra for A2BX6 (A = Rb;B = Tc, Pb, Pt, Sn, W, Ir, Ta, Sb, Te, Se, Mo, Mn, Ti, Zr and X = Cl, Br) materials have been proceeded utilizing Vanderbilt Ultra Soft Pseudo Potential (US-PP) process. The Rb2PbBr6 and Rb2PbCl6 are found to be a (Г-Г) semiconductors with energy gaps of 0.275 and 1.142 eV, respectively making them promising photovoltaic materials. The metallic behavior of the materials for Rb2BX6 (B = Tc, W, Ir, Ta, Mn, Sb, Mo) has been confirmed showing the attendance of conducting lineaments. The dielectric function is found to be large close to the ultraviolet districts (3.10 - 4.13 eV). The extinction coefficient of the Rb2BX6 has the ability to be used for implements. The band structures and density of states ensure the magnetic semiconductors’ nature of the Rb2Mn (Cl, Br)6 perovskites. The total calculated magnetic moment of Rb2MnCl6 and Rb2MnB6 is 3.00μβ. Advanced spintronic technology requires room-temperature ferromagnetism. The present work confirms that, bromine and chlorine-founded double perovskites are extremely attractive for photovoltaic and optoelectronic devices.
基金partially supported by the National Natural Science Foundation of China(Grant No.61775241)the Youth Innovation Team(Grant No:2019012)of CSU+3 种基金the Hunan province key research and development project(Grant No:2019GK2233)Hunan Province Graduate Research and Innovation Project(Grant No:CX20190177)the Science and Technology Innovation Basic Research Project of Shenzhen(Grant No.JCYJ20180307151237242)the funding support from the Australian Research Council(ARC Discovery Project,DP180102976).
文摘Spintronics,exploiting the spin degree of electrons as the information vector,is an attractive field for implementing the beyond Complemetary metal-oxide-semiconductor(CMOS)devices.Recently,two-dimensional(2D)materials have been drawing tremendous attention in spintronics owing to their distinctive spin-dependent properties,such as the ultralong spin relaxation time of graphene and the spin-valley locking of transition metal dichalcogenides.Moreover,the related heterostructures provide an unprecedented probability of combining the di erent characteristics via proximity e ect,which could remedy the limitation of individual 2D materials.Hence,the proximity engineering has been growing extremely fast and has made significant achievements in the spin injection and manipulation.Nevertheless,there are still challenges toward practical application;for example,the mechanism of spin relaxation in 2D materials is unclear,and the high-effciency spin gating is not yet achieved.In this review,we focus on 2D materials and related heterostructures to systematically summarize the progress of the spin injection,transport,manipulation,and application for information storage and processing.We also highlight the current challenges and future perspectives on the studies of spintronic devices based on 2D materials.
基金financially supported by the National Natural Science Foundation of China(Nos.51822101,51861135104,51771009 and 11704018).
文摘Our world is composed of various materials with different structures,where spin structures have been playing a pivotal role in spintronic devices of the contemporary information technology.Apart from conventional collinear spin materials such as collinear ferromagnets and collinear antiferromagnetic ally coupled materials,noncollinear spintronic materials have emerged as hot spots of research attention due to exotic physical phenomena.In this review,we first introduce two types of noncollinear spin structures,i.e.,the chiral spin structure that yields real-space Berry phases and the coplanar noncollinear spin structure that could generate momentum-space Berry phases,and then move to relevant novel physical phenomena including topological Hall effect,anomalous Hall effect,multiferroic,Weyl fermions,spin-polarized current and spin Hall effect without spin-orbit coupling in these noncollinear spin systems.Afterward,we summarize and elaborate the electric-field control of the noncollinear spin structure and related physical effects,which could enable ultralow power spintronic devices in future.In the final outlook part,we emphasize the importance and possible routes for experimentally detecting the intriguing theoretically predicted spin-polarized current,verifying the spin Hall effect in the absence of spin-orbit coupling and exploring the anisotropic magnetoresistance and domain-wall-related magnetoresistance effects for noncollinear antiferromagnetic materials.
基金supported by the National Key R&D Program of China (No. 2017YFA0206302)supported by the National Natural Science Foundation of China (Grants No. 51627801)+1 种基金the finical supports from the National Natural Science Foundation of China (Grants No. 11874409)supports from the Major Program of Aerospace Advanced Manufacturing Technology Research Foundation NSFC and CASC,China (No. U1537204)
文摘Magnetic orderings, i.e., the spontaneous alignment of electron spins below a critical temperature, have been playing key roles in modern science and technologies for both the wide applications of magnetic recording for information storage and the vibrant potential of solid state electronic spin devices (also known as spintronics) for logic operations. In the past decades, thanks to the development of thin film technologies, magnetic thin films via sputtering or epitaxial growth have made the spintronic devices possible at the industrial scale. Yet thinner materials at lower costs with more versatile functionalities are highly desirable for advancing future spintronics. Recently, van der Waals magnetic materials, a family of magnets that can in principle be exfoliated down to the monolayer limit, seem to have brought tremendous opportunities: new generation van der Waals spintronic devices can be seamlessly assembled with possible applications such as optoelectronics, flexible electronics, and etc. Moreover, those exfoliated spintronic devices can potentially be compatible with the famed metal-oxide field effect transistor architectures, allowing the harness of spin performances through the knob of an electrostatic field.
文摘Neuromorphic computing is the development of computingschemes inspired by the processing of information in thebrain, which can execute complex tasks very efficiently usingan architecture that is completely different from that of semiconductorchips. Recently, researchers from Tohoku Universityhave realized an artificial neuron and synapse in spintronicsdevices, which are promising for future energy-efficientand adoptive computing systems, as they behave likethe spiking neural network in human brains.
基金supported by the National Natural Science Foundation of China(Grant Nos.11274016 and 11474012)the National Basic Research Program of China(Grant Nos.2013CB932604 and 2012CB619304)
文摘Spintronics involves the study of active control and manipulation of spin degrees of freedom in solid-state systems. The fascinating spin-resolved properties of graphene motivate numerous researchers to study spintronics in graphene and other two-dimensional(2D) materials. Silicene, the silicon analog of graphene, is considered to be a promising material for spintronics. Here, we present a review of theoretical advances with regard to spin-dependent properties, including the electric field- and exchange field-tunable topological properties of silicene and the corresponding spintronic device simulations.
基金funding from Italian MIUR through PRIN project QCNa Mosthe support of Royal Society by International Exchange program (IES\R3\170274)
文摘Since its discovery in early 2000’s Molecular Spintronics has developed in an established and fructuous research field,achieving a number of outstanding results and unveiling unusual spintronic properties.Typically the most mysterious device element,the interface,in molecular spintronics has on contrary received and enormous attention and even gained a special nickname–the spinterface.Based on significant efforts of many research groups worldwide it has been established its critical role in defining the main functionalities of molecular spintronic devices.Noteworthily the spinterface was found to control the properties of the both components constituting the interface,not only those of the molecular layer but surprisingly also those of the magnetic counterpart.This paper aims to overview the most striking spinterface properties and to highlight the possibilities to promote new device paradigms based on interfacial modulation.
基金Project supported by the National Natural Science Foundation of China(Grant No.11274378)the Key Research Program of the Chinese Academy of Sciences(Grant No.XDPB08-3)the MOST of China(Grant No.2013CB933401)
文摘It is commonly known that the hydrodynamic equations can be derived from the Boltzmann equation. In this paper, we derive similar spin-dependent balance equations based on the spinor Boltzmann equation. Besides the usual charge current, heat current, and pressure tensor, we also explore the characteristic spin accumulation and spin current as well as the spin-dependent pressure tensor and heat current in spintronics. The numerical results of these physical quantities are demonstrated using an example of spin-polarized transport through a mesoscopic ferromagnet.
基金Project supported by the National Natural Science Foundation of China (Grant No. 51272174)the Natural Science Foundation of Tianjin City (Grant No. 12JCYBJC11100)
文摘Half metallic polycrystalline, epitaxial Fe3O4 films and Fe3O4 -based heterostructures for spintronics were fabricated by DC reactive magnetron sputtering. Large tunneling magnetoresistance was found in the polycrystalline Fe3O4 films and attributed to the insulating grain boundaries. The pinning effect of the moments at the grain boundaries leads to a significant exchange bias. Frozen interfacial/surface moments induce weak saturation of the high-field magnetoresistance. The films show a moment rotation related butterfly-shaped magnetoresistance. It was found that in the films, natural growth defects, antiphase boundaries, and magnetocrystalline anisotropy play important roles in high-order anisotropic magnetoresistance. Spin injection from Fe3O4 films to semiconductive Si and ZnO was measured to be 45% and 28.5%, respectively. The positive magnetoresistance in the Fe3O4 -based heterostructures is considered to be caused by a shift of the Fe3O4 e g ↑ band near the interface. Enhanced magnetization was observed in Fe3O4 /BiFeO 3 heterostructures experimentally and further proved by first principle calculations. The enhanced magnetization can be explained by spin moments of the thin BiFeO 3 layer substantially reversing into a ferromagnetic arrangement under a strong coupling that is principally induced by electronic orbital reconstruction at the interface.
基金Project supported by the National Basic Research Program of China(Grant No.2010CB923402)the National Natural Science Foundation of China(Grant Nos.11174181 and 21161160445)the 111 Project,China(Grant No.B13029)
文摘Recent progress in organic spintronics is given an informative overview, covering spin injection, detection, and trans-port in organic spin valve devices, and the magnetic field effect in organic semiconductors （OSCs）. In particular, we focus on our own recent work in spin injection and the organic magnetic field effect （OMFE）.
文摘Results of investigations of band structure, Fermi surface and effective masses of charge carriers in the ultrathin (monolayer graphene)/MnO(001) and MnO(001) films are presented using the method of the density functional theory. Features of spin states of valence band and Fermi level as well as an interatomic interaction in these systems are discussed. A magnetic moment at Mn atom is estimated and an effect of spin polarization at atoms of oxygen and carbon has been revealed which natures are discussed. By calculations of structural energies for 2D (monolayer graphene)/MnO(001) and 2D MnO(001) a stability of these systems has been ascertained. In the 2D (monolayer graphene)/MnO(001) and 2D MnO(001) systems the band structure calculations for the 2D systems mentioned above point out that tensor components of effective masses of both electrons and holes are in the ranges of (0.15 - 0.54) m0 and (0.38 - 1.27) m0 respectively. Mobility estimations of two-dimensional charge carriers for a 2D (monolayer graphene)/MnO(001)AF2 heterostructure have been performed.
基金supported financially by the National Natural Science Foundation of China(Grant Nos.52250008,52050171,51973043,22175047,52103203,and 52103338)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB36020000)+4 种基金the Ministry of Science and Technology of the People’s Republic of China(2017YFA0206600)the CAS Instrument Development Project(Grant No.YJKYYQ20170037)the Beijing Natural Science Foundation(Grant Nos.4222087,2222086)Natural Science Foundation of Shandong Province(Grant No.ZR2020ME070)the Beijing National Laboratory for Molecular Sciences(Grant No.BNLMS201907),and the CAS Pioneer Hundred Talents Program.
文摘Molecular spintronics,as an emerging field that makes full use of the advantage of ultralong room-temperature spin lifetime and abundant electrical-optical-magnetic properties of molecular semiconductors,has gained wide attention for its great potential for further commercial applications.Despite the significant progress that has been made,there remain several huge challenges that limit the future development of this field.This Perspective provides discussions on the spin transport mechanisms and performances of molecular semiconductors,spinterface effect,and related spin injection in spintronic devices,and current spin-charge interactive functionalities,along with the summarization of the main obstacles of these aspects.Furthermore,we particularly propose targeted solutions,aiming to enhance the spin injection and transport efficiency by molecular design and interface engineering and explore diverse spinrelated functionalities.Through this Perspective,we hope it will help the spintronic community identify the research trends and accelerate the development of molecular spintronics.
基金Project supported by the National Natural Science Foundation of China(Grant No.52173283).
文摘Two-dimensional(2D)ferrovalley materials with valley-dependent Hall effect have attracted great interest due to their significant applications in spintronics.In this paper,by using first-principles computational simulations,we predict that the ScBrCl monolayer is a 2D ferrovalley material with valley-dependent multiple Hall effects.After calculations,we found that the ScBrCl monolayer has excellent thermodynamic stability and kinetic stability,and has a high magnetic transition temperature.When the magnetization direction is turned from in-plane to out-of-plane,a large valley polarization of 44 meV can be generated.In particular,under 5.1%–5.3%tensile strain conditions,ScBrCl monolayer can achieve quantum anomalous Hall effect,and further prove its existence through non-zero Chern number and non-trivial edge state.Our discovery enriches the research on valley-dependent Hall effect and promotes the potential application of 2D Janus monolayer in valley electronics.
基金the supports from the National Natural Science Foundation of China (Grant No.11874070)the National Key R&D Program of China (Grant No.2018YFA0305601)+1 种基金the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No.XDB28000000)National Thousand-Young-Talents Program in China (Grant No.8206100161).
文摘Topological insulators are emergent states of quantum matter that are gapped in the bulk with timereversal symmetry-pteserved gapless edge/surface states, adiabatically distinct from conventional mat erials. By proximity to various magnets and superconductors, to pological insula tors show novel physics at the interfaces, which give rise to two new areas named topological spintronics and topological quantum compu tat ion. Effects in the former such as the spin to rques, spin-charge conversion, to pological antiferromagnetic spintronics, and skyrmions realized in topological systems will be addressed. In the latter, a superconducting pairing gap leads to a state that supports Majorana fermions states, which may provide a new path for realizing to pological quantum comp ut at ion. Various signa tu res of Majorana zero modes/edge mode in topological superconductors will be discussed. The review ends by outlooks and potential applications of topological insulators. Topological superconductors that are fabricated using topological insulators with superconductors have a full pairing gap in the bulk and gapless surface states consisting of Majorana fermions. The theory of topological superconductors is reviewed, in close analogy to the theory of topological insulators.
基金The authors acknowledge financial support from the Singapore Ministry of Education Tier 2 grant(MOE2016-T2-2-110)the A*STAR 2D PHAROS grant(R-144-000-359-305)R.Z.acknowledges support by NUS research scholarship.
文摘The unprecedented realization of two-dimensional(2D)van der Waals magnets excitingly extends the synergy between spintronics and 2D materials,started with graphene over the last decade.This article reviews the recent milestones in the development of 2D magnets and its derived heterostructures.In particular,a number of critical challenges centered around the scalability,ambient stability and Curie temperature of these atomically thin magnets are discussed.This mini-review also provides an outlook on what the future might hold for this integrated field of 2D spintronics,and assesses its potential in postsilicon electronics.
文摘In spintronics, it is highly desirable to find new materials that can simultaneously possess complete spin-polarization, high-speed conduction electrons, large Curie temperature, and robust ferromagnetic ground states. Using first-principles calculations, we demonstrate that the stable YN2 monolayer with octahedral coordination is a novel p-state Dirac half metal （DHM）, which not only has a fully spin-polarized Dirac state, but also the highest Fermi velocity （3.74×10^5 m/s） of the DHMs reported to date. In addition, its half-metallic gap of 1.53 eV is large enough to prevent the spin-flip transition. Because of the strong nonlocal p orbitals of N atoms （N-p） direct exchange interaction, the Curie temperature reaches over 332 K. Moreover, its ferromagnetic ground state can be well preserved under carrier doping or external strain. Therefore, the YN2 monolayer is a promising DHM for high-speed spintronic devices and would lead to new opportunities in designing other p-state DHMs.
基金financial support from the Humboldt Stiftung (Sofja Kovalevskaja Prize)the German DFG (SPP 1601)the BW Stiftung via the Kompetenznetz Funktionelle Nanostrukturen
文摘We review the progress and future possibilities in the emerging area of molecular spintronics. We first provide an overview of the different transport regimes in which electronic nanodevices can operate, then briefly overview the important characteristics of molecular magnetic materials that can be useful for application in spintronics and we eventually present several schemes to include such systems into spintronic nanodevices. We hightlight the importance of a chemical approach to the area, and in the last section we showcase some approaches to the creation of hybrids made of carbon nanostructures and molecular magnets, which are gaining increasing attention.
基金the National Key Research and Development Program of China(Grants No.2021YFB3601303,2021YFB3601300)the National Natural Science Foundation of China(Grants No.92164206,61904009,62001014 and 61627813)for their financial support of this work.
文摘Over the pas few decades,the diversified development of antiferomagnetic spintronics has made antiferomagnets(AFMs)interesting and very useful.After tough challenges,the applications of AFMs in electronic devices have transitioned from focusing on the interface coupling features to achieving the manipulation and detection of AFMs.As AFMs are internally magnetic,taking full use of AFMs for information storage has been the main target of research.In this paper,we provide a comprehensive description of AFM spintronics applications from the interface coupling,read-out operations,and writing manipulations perspective.We examine the early use of AFMs in magnetic recordings and conventional magnetoresistive random-access memory(MRAM),and review the latest mechanisms of the manipulation and detection of AFMs.Finally,based on exchange bias(EB)manipulation,a high-performance EB-MRAM is introduced as the next generation of AFM-based memories,which provides an effective method for read-out and writing of AFMs and opens a new era for AFM spintronics.
基金supported by the National Basic Research Program of China(Grant Nos. 2013CB934500 and 2012CB921302)the National Natural Science Foundation of China (Grant No. 91223204)the "100 Talents Project" of Chinese Academy of Sciences
文摘Carbon-based spintronics refers mainly to the spin injection and transport in carbon materials including carbon nanotubes,graphene,fullerene,and organic materials.In the last decade,extraordinary development has been achieved for carbon-based spintronics,and the spin transport has been studied in both local and nonlocal spin valve devices.A series of theoretical and experimental studies have been done to reveal the spin relaxation mechanisms and spin transport properties in carbon materials,mostly for graphene and carbon nanotubes.In this article,we provide a brief review on spin injection and transport in graphene,carbon nanotubes,fullerene and organic thin films.
