检索结果-南通市图书馆

Anisotropic spin transport and photoresponse characteristics detected by tip movement in magnetic single-molecule junction

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2024年第4期33卷 640-648页

作者：陈登辉羊志付新宇秦申奥严岩王传奎李宗良邱帅 Shandong Key Laboratory of Medical physics and Image Processing&Shandong Provincial Engineering and technical Center of Light Manipulations School of Physics and ElectronicsShandong Normal UniversityJinan 250358China

Orientation-dependent transport properties induced by anisotropic molecules are enticing in single-molecule junctions.Here,using the first-principles method,we theoretically investigate spin transport properties and photoresponse characteristics in trimesic acid magnetic single-molecule junctions with different molecular adsorption orientations and electrode contact sites.The transport calculations indicate that a single-molecule switch and a significant enhancement of spin transport and photoresponse can be achieved when the molecular adsorption orientation changes from planar geometry to upright geometry.The maximum spin polarization of current and photocurrent in upright molecular junctions exceeds 90%.Moreover,as the Ni tip electrode moves,the tunneling magnetoresistance of upright molecular junctions can be increased to 70%.The analysis of the spin-dependent PDOS elucidates that the spinterfaces between organic molecule and ferromagnetic electrodes are modulated by molecular adsorption orientation,where the molecule in upright molecular junctions yields higher spin polarization.Our theoretical work paves the way for designing spintronic devices and optoelectronic devices with anisotropic functionality base on anisotropic molecules.

关键词： molecular spintronics spin polarization tunneling magnetoresistance photocurrent single-molecule junctions

Evolution of artificial ion channels

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第1期11卷 72-73页

作者： Yugang Wang school of physics Peking University

Protein ion channels on a cell membrane generate action potentials for cellular signal transduction, and regulate biological activities during life. Since the discovery of the asymmetric ion transport phenomenon in quartz nanopipettes by Bard and colleagues [1], synthetic nanofluidic materials and devices have attracted a lot of research interests from the scientific community,

关键词：

Correlation between structural phase transition and physical properties of Co2+/Gd3+ co-substituted copper ferrite

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第7期42卷 1344-1353页

作者： Mohsen Choupani Ahmad Gholizadeh school of physics Damghan University

The doping of the spinel ferrites with selective cations usually improves the properties of the parent ferrite.The effect of Co2+/Gd3+co-substitution on the microstructure,optical,and magnetic properties of Cu1-xCoxFe2-xGdxO4prepared by the citrate-nitrate auto-combustion synthesis was investigated.Characterization of the samples was performed with powder X-ray diffraction（XRD）,Raman and Fouriertransform infrared（FTIR） spectroscopy,field-emission scanning electron microscopy,X-ray energydispersive spectroscopy,UV-Vis spectroscopy,and a vibrating sample magnetometer.The results of XRD,Raman,and FTIR analysis show a gradual structural phase transition from a tetragonal（I41/amd）structure to a cubic（Fd 3 m） structure.The bandgap energy of the studied samples is in a range of1.57-1.75 eV with a minimum in sample x=0,06 and then increases.Magnetic investigations show that the presence of Co2+/Gd3+cations in an octahedral site of the copper ferrite structure could increase saturation magnetization and coercive field from 567.9 Oe and 23.62 emu/g to 929.4 Oe and 28.27 emu/g,respectively.

关键词： Citrate-nitrate method Magnetic properties Microstructure properties Rare earths Spinel copper ferrite Structure phase transition

Even-odd layer-dependent multiferroic in freestanding rare-earth orthorhombic perovskite

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2024年第7期67卷 151-157页

作者： Shaowen Xu Fanhao Jia Ning Dai school of physics and Optoelectronic Engineering Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China Department of physics College of ScienceHangzhou Dianzi UniversityHangzhou 310018China State Key Laboratory of Infrared physics Shanghai Institute of Technical PhysicsChinese Academy of SciencesShanghai 200083China

Freestanding oxide perovskites possess strong interlayer coupling between adjacent atomic layers,thus exerting a determinative effect on the magnetism and ferroelectricity of these atomic-scale materials.Here,we propose an effective strategy to manipulate magnetism and ferroelectricity in freestanding rare-earth orthorhombic perovskite via modulation of layer thickness.By performing first-principles calculations,an even-odd oscillation is demonstrated in few-layer GdAlO_(3)perovskite(GAP).Specifically,odd-layer systems with charged atomic layers are ferromagnetic polar metals,while even-layer systems are antiferromagnetic ferroelectric semiconductors.This thickness-dependent magnetic phase transition originates from carrier doping,as rationalized by the Stoner criterion.Furthermore,we demonstrate the promotion of in-plane ferroelectricity via the concurrent application of two distinct antiferrodistortive displacements,each driven by formation and breaking of bonds.Analogous multiferroic phases may emerge in other transition metal oxide perovskites supporting multiple valence states,e.g.,few-layer Gd MO_(3)(M=V,Cr,Mn,and Ni).This work puts forward a strategy for layer thickness engineering of magnetism and ferroelectricity in 2D oxide perovskite multiferroic materials.

关键词： few-layer rare-earth perovskite multiferroicity size effect first principles calculations

Phenomenology of heavy neutral gauge boson at muon collider

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2024年第3期67卷 60-79页

作者： Zongyang Lu Honglei Li Zhi-Long Han Zong-Guo Si Liuxin Zhao school of physics and Technology University of JinanJinan 250022China school of physics Shandong UniversityJinan 250100China

Heavy neutral gauge boson Z' is proposed in many new physics models.It has rich phenomena at the future muon collider.We study the properties of Z' boson with the process of μ^(+)μ^(-)→qq,μ^(+)μ^(-)→l^(+)l^(-),μ^(+)μ^(-)→ ZH and μ^(+)μ^(-)→ W^(+)W^(-).The discrepancy of Z' coupling to different types of particles can be shown in the cross section distributions around the resonance peak of various decay modes.Angular distributions of the final quark or lepton in μ^(+)μ^(-)→qq/l^(+)l^(-)process are sensitive to the parameters such as mass of Z' and the Z-Z' mixing angle.The interaction of new gauge boson coupling to the standard model gauge particles and Higgs boson are also studied through μ^(+)μ^(-)→ ZH→l^(+)l^(-)bb and μ^(+)u^(-)→ W^(+)W^(-)→l^(+)l^(-)v_(l)v_(l).The cross section and the final particles' angular distributions with the contribution of Z' boson differ from those processes with only standard model particles.A forward-backward asymmetry defined by the angular distribution is provided to show the potential of searching for new physics at the muon collider.Especially,the beam polarization with certain value can effectively enlarge the forward-backward asymmetry.

关键词： Z′boson muon collider new physics

Hole-Doped Nonvolatile and Electrically Controllable Magnetism in van der Waals Ferroelectric Heterostructures

在线全文

学校读者我要写书评

暂无评论

Chinese physics Letters 2024年第5期41卷 107-119页

作者：姜新新王智宽李冲孙雪莲杨磊李冬梅崔彬刘德胜 school of physics National Demonstration Center for Experimental Physics EducationShandong UniversityJinan 250100China school of physics and Microelectronics Zhengzhou UniversityZhengzhou 450001China

Electrical control of magnetism in van der Waals semiconductors is a promising step towards development of two-dimensional spintronic devices with ultralow power consumption for processing and storing information.Here, we propose a design for two-dimensional van der Waals heterostructures(vdWHs) that can host ferroelectricity and ferromagnetism simultaneously under hole doping. By contacting an In Se monolayer and forming an InSe/In_(2)Se_(3) vd WH, the switchable built-in electric field from the reversible out-of-plane polarization enables robust control of the band alignment. Furthermore, switching between the two ferroelectric states(P_↑ and P_↓)of hole-doped In_(2)Se_(3) with an external electric field can interchange the ON and OFF states of the nonvolatile magnetism. More interestingly, doping concentration and strain can effectively tune the magnetic moment and polarization energy. Therefore, this provides a platform for realizing multiferroics in ferroelectric heterostructures,showing great potential for use in nonvolatile memories and ferroelectric field-effect transistors.

关键词： polarization ferroelectric doping

Environment-adaptive phase-separation-porous fluorofilm for highperformance passive radiation cooling

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第6期17卷 5636-5644页

作者： Weiming Tang Yong Li Xue Meng Shutao Wang Ziguang Zhao school of Future Technology University of Chinese Academy of SciencesBeijing 100049China CAS Key Laboratory of Bio-inspired Materials and Interfacial Science Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China CAS Key Laboratory of Cryogenics Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China

Passive radiative cooling is widely recognized as an environmentally sustainable method for achieving significant cooling effects.However,the mechanical properties and environmental adaptability of current radiative cooling materials are not sufficient to maintain high cooling performance in external environments.Here we reported an environment-adaptive phase-separation-porous fluorofilm for high-performance passive radiation cooling.Compared to the homogenous fluoro-porous network with limited scattering efficiencies,we modulated the porous structure of the fluorofilm to achieve a strong emissivity of 95.2%(8-13μm)and a high reflectivity of 97.1%(0.3-2.5μm).The fluorofilm demonstrates a temperature drop of 10.5°C and an average cooling power of 81 W·m^(−2)under a sunlight power of 770 W·m^(−2).The high mechanical performance and environmental adaptability of fluorofilms are also exhibited.Considering its significant radiative cooling capability and robust environmental adaptability,the fluorofilm is expected to have a promising future in radiative temperature regulation.

关键词： fluorofilm passive radiation cooling porous optimization thermal regulation

Lateral photovoltaic effect in the Ni-SiO_(2)-Si structure with bias

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Optoelectronics Letters 2024年第5期20卷 257-264页

作者： LING Xiang ZHU Pengfei ZHU Kun SONG Pei LI Xiong school of Mathematics Physics and StatisticsShanghai University of Engineering ScienceShanghai 201600China school of Electrical Engineering Liupanshui Normal UniversityLiupanshui 553004China school of Railway Telecommunication Hunan Technical College of Railway High-speedHengyang 421002China

We designed a clamping device to study lateral photovoltaic effect (LPE) in Ni-SiO_(2)-Si structure with bias due to the appropriate barrier height.The LPE has a prominent sensitivity and linearity with 532 nm wavelength laser.The transient response time is 450μs and the relaxation time is 2 250μs in the Ni-SiO_(2)-Si structure without bias.The LPE sensitivity has a significant improvement with bias.The transient response time is 6μs and the relaxion time is 47μs with-7 V bias,not only improving the LPE sensitivity,but also increasing the response speed with bias.The research shows that the Schottky barrier structure can improve the sensitivity and linearity of LPE with bias effectively,and thus it can be used in position sensitive sensors.

关键词： LPE structure effect

Effect of cognitive training on brain dynamics

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2024年第2期33卷 529-536页

作者：吕贵阳徐天勇陈飞燕朱萍王淼何国光 school of physics Zhejiang UniversityHangzhou 310027China

The human brain is highly plastic.Cognitive training is usually used to modify functional connectivity of brain networks.Moreover,the structures of brain networks may determine its dynamic behavior which is related to human cognitive abilities.To study the effect of functional connectivity on the brain dynamics,the dynamic model based on functional connections of the brain and the Hindmarsh–Rose model is utilized in this work.The resting-state fMRI data from the experimental group undergoing abacus-based mental calculation(AMC)training and from the control group are used to construct the functional brain networks.The dynamic behavior of brain at the resting and task states for the AMC group and the control group are simulated with the above-mentioned dynamic model.In the resting state,there are the differences of brain activation between the AMC group and the control group,and more brain regions are inspired in the AMC group.A stimulus with sinusoidal signals to brain networks is introduced to simulate the brain dynamics in the task states.The dynamic characteristics are extracted by the excitation rates,the response intensities and the state distributions.The change in the functional connectivity of brain networks with the AMC training would in turn improve the brain response to external stimulus,and make the brain more efficient in processing tasks.

关键词： brian dynamics functional brain networks cognitive training abacus-based mental calculation