In this paper, a method of transforming volume integrals to boundary integrals is given for complicated loadings such as a i(y)x i and b i(x)y i . In the present method the volume in...In this paper, a method of transforming volume integrals to boundary integrals is given for complicated loadings such as a i(y)x i and b i(x)y i . In the present method the volume integrals are approximately transformed to boundary integrals.展开更多
We mainly consider a class of two dimensional normal type singular integral equations, the solutions as well as the conditions of solvability of which are obtained .The methods used consist of transferring them to sev...We mainly consider a class of two dimensional normal type singular integral equations, the solutions as well as the conditions of solvability of which are obtained .The methods used consist of transferring them to several one dimensional Riemann boundary value problems, and then solving the latter.展开更多
Compared to the well-studied two-dimensional(2D)ferroelectricity,the appearance of 2D antiferroelectricity is much rarer,where local dipoles from the nonequivalent sublattices within 2D monolayers are oppositely orien...Compared to the well-studied two-dimensional(2D)ferroelectricity,the appearance of 2D antiferroelectricity is much rarer,where local dipoles from the nonequivalent sublattices within 2D monolayers are oppositely oriented.Using NbOCl_(2) monolayer with competing ferroelectric(FE)and antiferroelectric(AFE)phases as a 2D material platform,we demonstrate the emergence of intrinsic antiferroelectricity in NbOCl_(2) monolayer under experimentally accessible shear strain,along with new functionality associated with electric field-induced AFE-to-FE phase transition.Specifically,the complex configuration space accommodating FE and AFE phases,polarization switching kinetics,and finite temperature thermodynamic properties of 2D NbOCl_(2) are all accurately predicted by large-scale molecular dynamics simulations based on deep learning interatomic potential model.Moreover,room temperature stable antiferroelectricity with low polarization switching barrier and one-dimensional collinear polarization arrangement is predicted in shear-deformed NbOCl_(2) monolayer.The transition from AFE to FE phase in 2D NbOCl_(2) can be triggered by a low critical electric field,leading to a double polarization–electric(P–E)loop with small hysteresis.A new type of optoelectronic device composed of AFE-NbOCl_(2) is proposed,enabling electric“writing”and nonlinear optical“reading”logical operation with fast operation speed and low power consumption.展开更多
The growth of single-crystalα-Al_(2)O_(3) is crucial for a variety of applications in electronics and other fields,while the synthesis of its two-dimensional(2D)form is not easy due to the high activation energy.Here...The growth of single-crystalα-Al_(2)O_(3) is crucial for a variety of applications in electronics and other fields,while the synthesis of its two-dimensional(2D)form is not easy due to the high activation energy.Here,we demonstrate the growth of single-crystal 2Dα-Al_(2)O_(3) by high temperature(high-T)annealing of Ni foils.Tens of micrometers of 2Dα-Al_(2)O_(3) flakes grow on the surface of Ni foils,which is attributed to the precipitation of Al atoms from the Ni foil bulk to its surface,followed by the oxidation of Al atoms on the surface.In principle,the Ni foil acts as a solvent,where diluted metal atoms precipitate onto the surface and react with oxygen from the atmosphere to grow single-crystal 2D metal oxides.Our findings may also provide a promising method for synthesizing other single-crystal 2D metal oxides.展开更多
With the rapid development of information technology,the demand for high-performance and low-power microprocessors continues to grow.Traditional silicon-based semiconductor technologies have encountered numerous bottl...With the rapid development of information technology,the demand for high-performance and low-power microprocessors continues to grow.Traditional silicon-based semiconductor technologies have encountered numerous bottlenecks in performance enhancement,such as drain-induced barrier lowering,reduced mobility caused by interface scattering,and limited current on/off ratios.展开更多
The two-dimensional van der Waals layered semiconductor In_(2)Se_(3) has emerged as a promising candidate for non-volatile ferroelectric memory,optoelectronic devices,and polymorphic phase engineering.Polymorphic In_(...The two-dimensional van der Waals layered semiconductor In_(2)Se_(3) has emerged as a promising candidate for non-volatile ferroelectric memory,optoelectronic devices,and polymorphic phase engineering.Polymorphic In_(2)Se_(3) typically stabilizes in three distinct phases:α-,β′-,and β^(*)-In_(2)Se_(3),each dominant within specific temperature ranges.Although the crystal structures and ferroelectric properties of these phases have been widely studied,the unambiguous assignment of their in-plane and out-of-plane ferroelectric behaviors,as well as the mechanisms governing their phase transitions,remains a subject of active debate.In this study,we investigate the evolution of atomic and electronic structures in molecular beam epitaxy-grown ultrathin In_(2)Se_(3) films through correlated microstructural and macroscopic physical property analysis.By employing scanning tunneling microscopy/spectroscopy,temperature-dependent Raman spectroscopy,and piezoresponse force microscopy,we demonstrate a reversible temperature-induced phase transition between the in-plane ferroelectric β^(*)and antiferroelectric β′phases.Furthermore,we confirm robust out-of-plane ferroelectric polarization in the as-grown films and achieve an electric-field-driven transition from the β^(*)to β′phase.Our findings not only advance the fundamental understanding of phase transitions and polarization evolution in two-dimensional semiconductors but also open new avenues for the design of tunable,non-volatile ferroelectric memory devices.展开更多
Heat dissipation and thermal switches are vital for adaptive cooling and extending the lifespan of electronic devices and batteries. In this work, we conducted high-throughput investigations on the thermal transport o...Heat dissipation and thermal switches are vital for adaptive cooling and extending the lifespan of electronic devices and batteries. In this work, we conducted high-throughput investigations on the thermal transport of 24 experimentally realized two-dimensional(2D) materials and their potential as thermal switches, leveraging machine-learning-assisted strain engineering and phonon transport simulations. We identified several highperformance thermal switches with ratios exceeding 2, with germanene(Ge) achieving an ultrahigh ratio of up to9.64 within the reversible deformation range. The underlying mechanism is strain-induced bond softening, which sensitively affects anharmonicity represented by three-and four-phonon scattering. The widespread occurrence of four-phonon scattering was confirmed in the thermal transport of 2D materials. Opposite switching trends were discovered, with 2D transition metal dichalcogenide materials showing negative responses to tensile strain while buckled 2D elemental materials showed positive responses. We further proposed a screening descriptor based on strain-induced changes in the Gr¨uneisen parameter for efficiently identifying new high-performance thermal switch materials. This work establishes a paradigm for thermal energy control in 2D materials through strain engineering, which may be experimentally realized in the future via bending, substrate mismatch, and related approaches, thereby laying a robust foundation for further developments and applications.展开更多
Two-dimensional(2D)fully compensated collinear magnetic materials ofer signifcant advantages for spintronic applications,including robustness against magnetic feld perturbations,no stray felds,and ultrafast dynamics.A...Two-dimensional(2D)fully compensated collinear magnetic materials ofer signifcant advantages for spintronic applications,including robustness against magnetic feld perturbations,no stray felds,and ultrafast dynamics.Among these materials,fully compensated ferrimagnets are particularly promising due to their unique characteristics such as the magneto-optical efect,completely spin-polarized currents,and the anomalous Hall efect.We performed a structural search on 2D unconventional stoichiometric Cr-I crystals using a global optimization algorithm.The most stable CrI-P21/m monolayer is a fully compensated ferrimagnetic semiconductor with a band gap of 1.57 eV and a high magnetic transition temperature of 592 K.The spontaneous spin splitting in CrI-P21/m originates from the inequivalent local coordination environments of Cr^(1)and Cr^(2)ions,yielding a mismatch in their 3d orbitals splitting.Notably,carrier doping at a concentration of 0.01 electrons or holes per atom enables reversible spin polarization,generating a fully spin-polarized current in CrI-P21/m.This performance makes it a highly promising candidate for spintronic devices.Our fndings not only provide a structural paradigm for discovering fully compensated ferrimagnets but also open a new avenue for designing zero-moment magnetic materials with intrinsic spin splitting.展开更多
1 Introduction In highway construction,flled embankments are trapezoidal,and the ground is always improved by sand wells or columns.During embankment construction,because the width and height of the embankment are cha...1 Introduction In highway construction,flled embankments are trapezoidal,and the ground is always improved by sand wells or columns.During embankment construction,because the width and height of the embankment are changing,a non-uniform load that varies with time and lateral location is applied to the underlying ground.The consolidation phenomenon under two-dimensional(2D)conditions will keep pace with the construction of the embankment.In addition,because of evaporation and rainfall,the soils are mostly unsaturated.Therefore,it is meaningful to research the consolidation properties of unsaturated ground under non-uniform loading.展开更多
The two-dimensional kagome lattice serves as a prototypical platform for exploring quantum spin liquids owing to its pronounced geometric frustration.Substantial advancements have been achieved in herbertsmithite and ...The two-dimensional kagome lattice serves as a prototypical platform for exploring quantum spin liquids owing to its pronounced geometric frustration.Substantial advancements have been achieved in herbertsmithite and its structural analogs.These quantum spin liquid candidates exhibit large superexchange interactions yet resist magnetic ordering down to the lowest measurable temperatures,which are typically three or four orders of magnitude below the energy scale of the primary exchange energies.Nevertheless,the existence of unavoidable intrinsic interlayer magnetic impurities leads to persistent debates on their ground states.A breakthrough emerged with the discovery of YCu_(3)(OH)_(6+x)X_(3-x)(X=Cl,Br),a novel material family rigorously verifed to eliminate magnetic impurity interference.This short review highlights critical advances in these materials,emphasizing experimental signatures consistent with a Dirac quantum spin liquid and the observation of a oneninth magnetization plateau and possible quantum oscillations.Local structural characteristics play a crucial role in clarifying the complex emergent quantum phenomena of these materials.Collectively,these fndings establish this material class as a promising platform for investigating quantum spin liquid behavior in two-dimensional kagome lattices.展开更多
The crossover between short-range and long-range(LR)universal behaviors remains a central theme in the physics of LR interacting systems.The competition between LR coupling and the Berezinskii-Kosterlitz-Thouless mech...The crossover between short-range and long-range(LR)universal behaviors remains a central theme in the physics of LR interacting systems.The competition between LR coupling and the Berezinskii-Kosterlitz-Thouless mechanism makes the problem more subtle and less understood in the two-dimensional(2D)XY model,a cornerstone for investigating low-dimensional phenomena and their implications in quantum computation.We study the 2D XY model with algebraically decaying interaction~1/r^(2+σ).Utilizing an advanced update strategy,we conduct LR Monte Carlo simulations of the model up to a linear size of L=8192.Our results demonstrate continuous phase transitions into a ferromagnetic phase forσ<2,which exhibit the simultaneous emergence of a long-ranged order and a power-law decaying correlation function due to the Goldstone mode.Furthermore,we fnd logarithmic scaling behaviors in the low-temperature phase atσ=2.The observed scaling behaviors in the low-temperature phase forσ≤2 agree with our theoretical analysis.Our fndings request further theoretical understanding and can be of practical application in cutting-edge experiments like Rydberg atom arrays.展开更多
In this paper,the physics informed neural network(PINN)deep learning method is applied to solve two-dimensional nonlocal equations,including the partial reverse space y-nonlocal Mel'nikov equation,the partial reve...In this paper,the physics informed neural network(PINN)deep learning method is applied to solve two-dimensional nonlocal equations,including the partial reverse space y-nonlocal Mel'nikov equation,the partial reverse space-time nonlocal Mel'nikov equation and the nonlocal twodimensional nonlinear Schr?dinger(NLS)equation.By the PINN method,we successfully derive a data-driven two soliton solution,lump solution and rogue wave solution.Numerical simulation results indicate that the error range between the data-driven solution and the exact solution is relatively small,which verifies the effectiveness of the PINN deep learning method for solving high dimensional nonlocal equations.Moreover,the parameter discovery of the partial reverse space-time nonlocal Mel'nikov equation is analysed in terms of its soliton solution for the first time.展开更多
The precise control of wrinkles and strain gradients in nanofilm is of significant interest due to their profound influence on electronic band structures and spin states.Here,we employ ultrafast electron diffraction(U...The precise control of wrinkles and strain gradients in nanofilm is of significant interest due to their profound influence on electronic band structures and spin states.Here,we employ ultrafast electron diffraction(UED)to study the picosecond-scale dynamics of laser-induced bending in 2H-MoTe2 thin films.展开更多
Phase transitions,as one of the most intriguing phenomena in nature,are divided into first-order phase transitions(FOPTs)and continuous ones in current classification.While the latter shows striking phenomena of scali...Phase transitions,as one of the most intriguing phenomena in nature,are divided into first-order phase transitions(FOPTs)and continuous ones in current classification.While the latter shows striking phenomena of scaling and universality,the former has recently also been demonstrated to exhibit scaling and universal behavior within a mesoscopic,coarse-grained Landau-Ginzburg theory.Here we apply this theory to a microscopic model-the paradigmatic Ising model,which undergoes FOPTs between two ordered phases below its critical temperature-and unambiguously demonstrate universal scaling behavior in such FOPTs.These results open the door for extending the theory to other microscopic FOPT systems and experimentally testing them to systematically uncover their scaling and universal behavior.展开更多
The presence of a van Hove singularity(vHS)at the Fermi level can trigger magnetic instability by mediating a spontaneous transition from paramagnetic to magnetically ordered states.While electrostatic doping(typicall...The presence of a van Hove singularity(vHS)at the Fermi level can trigger magnetic instability by mediating a spontaneous transition from paramagnetic to magnetically ordered states.While electrostatic doping(typically achieved via ionic gating)to shift the vHS to the Fermi level provides a general mechanism for engineering such magnetism,its volatile nature often leads to the collapse of induced states upon gate field removal.Here,a novel scheme is presented for non-volatile magnetic control by utilizing ferroelectric heterostructures to achieve reversible magnetism switching.Using two-dimensional VSiN_(3),a nonmagnetic material with Mexican-hat electronic band dispersions hosting vHSs,as a prototype,it is preliminarily demonstrated that both electron and hole doping can robustly induce magnetism.Further,by interfacing VSiN_(3)with ferroelectric Sc_(2)CO_(2),reversible switching of its magnetic state via polarization-driven heterointerfacial charge transfer is achieved.This mechanism enables a dynamic transition between insulating and half-metallic phases in VSiN_(3),establishing a pathway to design multiferroic tunnel junctions with giant tunneling electroresistance or magnetoresistance.This work bridges non-volatile ferroelectric control with vHS-enhanced magnetism,opening opportunities for energy-efficient and high-performance spintronic devices and non-volatile memory devices.展开更多
Anion exchange membrane fuel cells(AEMFCs),regarded as a promising alternative to proton exchange membrane fuel cells(PEMFCs),have garnered increasing attention because of their cost-effectiveness by using the non-nob...Anion exchange membrane fuel cells(AEMFCs),regarded as a promising alternative to proton exchange membrane fuel cells(PEMFCs),have garnered increasing attention because of their cost-effectiveness by using the non-noble metal catalysts and hydrocarbon-based ionomers as membrane[1].However,despite of extensive researches on non-noble metal catalysts such as Co[2].展开更多
Two dimensional parabolic stability equations (PSE) are numerically solved using expansions in orthogonal functions in the normal direction.The Chebyshev polynomials approximation,which is a very useful form of ortho...Two dimensional parabolic stability equations (PSE) are numerically solved using expansions in orthogonal functions in the normal direction.The Chebyshev polynomials approximation,which is a very useful form of orthogonal expansions, is applied to solving parabolic stability equations. It is shown that results of great accuracy are effectively obtained.The availability of using Chebyshev approximations in parabolic stability equations is confirmed.展开更多
As rapeseed is a major oil crop with high quality vegetable oil and feed protein in China and the two-dimensional gel electrophoresis （2-DE） is an efficient technique for investigating protein expression, this paper...As rapeseed is a major oil crop with high quality vegetable oil and feed protein in China and the two-dimensional gel electrophoresis （2-DE） is an efficient technique for investigating protein expression, this paper reviews the innovations in 2-DE and its application in the studies of rapeseed. We conclude that 2-DE has provided much valuable information on rapeseed, and it will do more for rapeseed proteomic research in the near future with the technology innovations.展开更多
The experimental study of vertical jet in a two dimensional fluidized bed is presented. The time series of vertical jet penetration depth are acquired by image processing. The fluctuation of jet which is studied by m...The experimental study of vertical jet in a two dimensional fluidized bed is presented. The time series of vertical jet penetration depth are acquired by image processing. The fluctuation of jet which is studied by means of Hurst's analysis becomes weaker with increase in jet velocity, fluidization number, particle diameter and static bed height. They are found that the signal is persistent and the fractal dimensional of vertical jet is between 1.19 and 1.64.展开更多
Coherent exciton-phonon coupling in CdSe/ZnS nanocrystals have been investigated by temperature-dependent two-dimensional electronic spectroscopy （2DES） measurements. Benefiting from the ability of 2DES to dissect a...Coherent exciton-phonon coupling in CdSe/ZnS nanocrystals have been investigated by temperature-dependent two-dimensional electronic spectroscopy （2DES） measurements. Benefiting from the ability of 2DES to dissect assembles in nanocrystal films, we have dearly identified experimental evidences of coherent coupling between exciton and phonon in CdSe/ZnS nanocrystals. In time domain, 2DES signals of excitonic transitions beat at a frequency resonant to a longitudinal optical phonon mode; in energy domain, phonon side bands are distinct at both Stokes and anti-Stokes sides. When temperature increases, phonon-induced exciton dephasing is observed with dramatic broadening of homogeneous linewidth. The results suggest exciton-phonon coupling is essential in elucidating the quantum dynamics of excitonic transitions in semiconductor nanocrystals.展开更多
文摘In this paper, a method of transforming volume integrals to boundary integrals is given for complicated loadings such as a i(y)x i and b i(x)y i . In the present method the volume integrals are approximately transformed to boundary integrals.
文摘We mainly consider a class of two dimensional normal type singular integral equations, the solutions as well as the conditions of solvability of which are obtained .The methods used consist of transferring them to several one dimensional Riemann boundary value problems, and then solving the latter.
基金supported by the National Natural Science Foundation of China (Grant No.11574244 for G.Y.G.)the XJTU Research Fund for AI Science (Grant No.2025YXYC011 for G.Y.G.)the Hong Kong Global STEM Professorship Scheme (for X.C.Z.)。
文摘Compared to the well-studied two-dimensional(2D)ferroelectricity,the appearance of 2D antiferroelectricity is much rarer,where local dipoles from the nonequivalent sublattices within 2D monolayers are oppositely oriented.Using NbOCl_(2) monolayer with competing ferroelectric(FE)and antiferroelectric(AFE)phases as a 2D material platform,we demonstrate the emergence of intrinsic antiferroelectricity in NbOCl_(2) monolayer under experimentally accessible shear strain,along with new functionality associated with electric field-induced AFE-to-FE phase transition.Specifically,the complex configuration space accommodating FE and AFE phases,polarization switching kinetics,and finite temperature thermodynamic properties of 2D NbOCl_(2) are all accurately predicted by large-scale molecular dynamics simulations based on deep learning interatomic potential model.Moreover,room temperature stable antiferroelectricity with low polarization switching barrier and one-dimensional collinear polarization arrangement is predicted in shear-deformed NbOCl_(2) monolayer.The transition from AFE to FE phase in 2D NbOCl_(2) can be triggered by a low critical electric field,leading to a double polarization–electric(P–E)loop with small hysteresis.A new type of optoelectronic device composed of AFE-NbOCl_(2) is proposed,enabling electric“writing”and nonlinear optical“reading”logical operation with fast operation speed and low power consumption.
基金supported by Shenzhen Science and Technology Program(No.KQTD20200820113010022).
文摘The growth of single-crystalα-Al_(2)O_(3) is crucial for a variety of applications in electronics and other fields,while the synthesis of its two-dimensional(2D)form is not easy due to the high activation energy.Here,we demonstrate the growth of single-crystal 2Dα-Al_(2)O_(3) by high temperature(high-T)annealing of Ni foils.Tens of micrometers of 2Dα-Al_(2)O_(3) flakes grow on the surface of Ni foils,which is attributed to the precipitation of Al atoms from the Ni foil bulk to its surface,followed by the oxidation of Al atoms on the surface.In principle,the Ni foil acts as a solvent,where diluted metal atoms precipitate onto the surface and react with oxygen from the atmosphere to grow single-crystal 2D metal oxides.Our findings may also provide a promising method for synthesizing other single-crystal 2D metal oxides.
文摘With the rapid development of information technology,the demand for high-performance and low-power microprocessors continues to grow.Traditional silicon-based semiconductor technologies have encountered numerous bottlenecks in performance enhancement,such as drain-induced barrier lowering,reduced mobility caused by interface scattering,and limited current on/off ratios.
基金supported by the National Natural Science Foundation of China(Grant Nos.92365203,12534013,12174096,and 12474167)the Hunan Provincial Science Fund for Distinguished Young Scholars(Grant No.2022JJ10060)+1 种基金the Science and Technology Innovation Program of Hunan Province(Grant Nos.2025ZYJ001 and 2021RC4026)the Science Fund for Self-initiated Innovation of NUDT。
文摘The two-dimensional van der Waals layered semiconductor In_(2)Se_(3) has emerged as a promising candidate for non-volatile ferroelectric memory,optoelectronic devices,and polymorphic phase engineering.Polymorphic In_(2)Se_(3) typically stabilizes in three distinct phases:α-,β′-,and β^(*)-In_(2)Se_(3),each dominant within specific temperature ranges.Although the crystal structures and ferroelectric properties of these phases have been widely studied,the unambiguous assignment of their in-plane and out-of-plane ferroelectric behaviors,as well as the mechanisms governing their phase transitions,remains a subject of active debate.In this study,we investigate the evolution of atomic and electronic structures in molecular beam epitaxy-grown ultrathin In_(2)Se_(3) films through correlated microstructural and macroscopic physical property analysis.By employing scanning tunneling microscopy/spectroscopy,temperature-dependent Raman spectroscopy,and piezoresponse force microscopy,we demonstrate a reversible temperature-induced phase transition between the in-plane ferroelectric β^(*)and antiferroelectric β′phases.Furthermore,we confirm robust out-of-plane ferroelectric polarization in the as-grown films and achieve an electric-field-driven transition from the β^(*)to β′phase.Our findings not only advance the fundamental understanding of phase transitions and polarization evolution in two-dimensional semiconductors but also open new avenues for the design of tunable,non-volatile ferroelectric memory devices.
基金supported bythe Science and Technology Commission of Shanghai Municipality (Grant No.24CL2901702)The numerical calculations were performed at the Supercomputer Center (Project No.2024-Cb-0042)Institute for Solid State Physics,the University of Tokyo。
文摘Heat dissipation and thermal switches are vital for adaptive cooling and extending the lifespan of electronic devices and batteries. In this work, we conducted high-throughput investigations on the thermal transport of 24 experimentally realized two-dimensional(2D) materials and their potential as thermal switches, leveraging machine-learning-assisted strain engineering and phonon transport simulations. We identified several highperformance thermal switches with ratios exceeding 2, with germanene(Ge) achieving an ultrahigh ratio of up to9.64 within the reversible deformation range. The underlying mechanism is strain-induced bond softening, which sensitively affects anharmonicity represented by three-and four-phonon scattering. The widespread occurrence of four-phonon scattering was confirmed in the thermal transport of 2D materials. Opposite switching trends were discovered, with 2D transition metal dichalcogenide materials showing negative responses to tensile strain while buckled 2D elemental materials showed positive responses. We further proposed a screening descriptor based on strain-induced changes in the Gr¨uneisen parameter for efficiently identifying new high-performance thermal switch materials. This work establishes a paradigm for thermal energy control in 2D materials through strain engineering, which may be experimentally realized in the future via bending, substrate mismatch, and related approaches, thereby laying a robust foundation for further developments and applications.
基金supported by the Natural Science Foundation of Wenzhou Institute,University of Chinese Academy of Sciences(UCAS)(Grant No.WIUCASQD2023004)the National Natural Science Foundation of China(Grant Nos.12304006,12404265,and 12435001)+2 种基金the Natural Science Foundation of Shanghai,China(Grant No.23JC1401400)the Natural Science Foundation of Wenzhou(Grant No.L2023005)the Fundamental Research Funds for the Central Universities of East China University of Science and Technology。
文摘Two-dimensional(2D)fully compensated collinear magnetic materials ofer signifcant advantages for spintronic applications,including robustness against magnetic feld perturbations,no stray felds,and ultrafast dynamics.Among these materials,fully compensated ferrimagnets are particularly promising due to their unique characteristics such as the magneto-optical efect,completely spin-polarized currents,and the anomalous Hall efect.We performed a structural search on 2D unconventional stoichiometric Cr-I crystals using a global optimization algorithm.The most stable CrI-P21/m monolayer is a fully compensated ferrimagnetic semiconductor with a band gap of 1.57 eV and a high magnetic transition temperature of 592 K.The spontaneous spin splitting in CrI-P21/m originates from the inequivalent local coordination environments of Cr^(1)and Cr^(2)ions,yielding a mismatch in their 3d orbitals splitting.Notably,carrier doping at a concentration of 0.01 electrons or holes per atom enables reversible spin polarization,generating a fully spin-polarized current in CrI-P21/m.This performance makes it a highly promising candidate for spintronic devices.Our fndings not only provide a structural paradigm for discovering fully compensated ferrimagnets but also open a new avenue for designing zero-moment magnetic materials with intrinsic spin splitting.
基金supported by the National Nature Science Foundation of China(No.12172211)the National Key Research and Development Program of China(No.2019YFC1509800)。
文摘1 Introduction In highway construction,flled embankments are trapezoidal,and the ground is always improved by sand wells or columns.During embankment construction,because the width and height of the embankment are changing,a non-uniform load that varies with time and lateral location is applied to the underlying ground.The consolidation phenomenon under two-dimensional(2D)conditions will keep pace with the construction of the embankment.In addition,because of evaporation and rainfall,the soils are mostly unsaturated.Therefore,it is meaningful to research the consolidation properties of unsaturated ground under non-uniform loading.
文摘The two-dimensional kagome lattice serves as a prototypical platform for exploring quantum spin liquids owing to its pronounced geometric frustration.Substantial advancements have been achieved in herbertsmithite and its structural analogs.These quantum spin liquid candidates exhibit large superexchange interactions yet resist magnetic ordering down to the lowest measurable temperatures,which are typically three or four orders of magnitude below the energy scale of the primary exchange energies.Nevertheless,the existence of unavoidable intrinsic interlayer magnetic impurities leads to persistent debates on their ground states.A breakthrough emerged with the discovery of YCu_(3)(OH)_(6+x)X_(3-x)(X=Cl,Br),a novel material family rigorously verifed to eliminate magnetic impurity interference.This short review highlights critical advances in these materials,emphasizing experimental signatures consistent with a Dirac quantum spin liquid and the observation of a oneninth magnetization plateau and possible quantum oscillations.Local structural characteristics play a crucial role in clarifying the complex emergent quantum phenomena of these materials.Collectively,these fndings establish this material class as a promising platform for investigating quantum spin liquid behavior in two-dimensional kagome lattices.
基金supported by the National Natural Science Foundation of China(Grant Nos.12204173 and 12275263)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301900)supported by the Natural Science Foundation of Fujian Province 802 of China(Grant No.2023J02032)。
文摘The crossover between short-range and long-range(LR)universal behaviors remains a central theme in the physics of LR interacting systems.The competition between LR coupling and the Berezinskii-Kosterlitz-Thouless mechanism makes the problem more subtle and less understood in the two-dimensional(2D)XY model,a cornerstone for investigating low-dimensional phenomena and their implications in quantum computation.We study the 2D XY model with algebraically decaying interaction~1/r^(2+σ).Utilizing an advanced update strategy,we conduct LR Monte Carlo simulations of the model up to a linear size of L=8192.Our results demonstrate continuous phase transitions into a ferromagnetic phase forσ<2,which exhibit the simultaneous emergence of a long-ranged order and a power-law decaying correlation function due to the Goldstone mode.Furthermore,we fnd logarithmic scaling behaviors in the low-temperature phase atσ=2.The observed scaling behaviors in the low-temperature phase forσ≤2 agree with our theoretical analysis.Our fndings request further theoretical understanding and can be of practical application in cutting-edge experiments like Rydberg atom arrays.
文摘In this paper,the physics informed neural network(PINN)deep learning method is applied to solve two-dimensional nonlocal equations,including the partial reverse space y-nonlocal Mel'nikov equation,the partial reverse space-time nonlocal Mel'nikov equation and the nonlocal twodimensional nonlinear Schr?dinger(NLS)equation.By the PINN method,we successfully derive a data-driven two soliton solution,lump solution and rogue wave solution.Numerical simulation results indicate that the error range between the data-driven solution and the exact solution is relatively small,which verifies the effectiveness of the PINN deep learning method for solving high dimensional nonlocal equations.Moreover,the parameter discovery of the partial reverse space-time nonlocal Mel'nikov equation is analysed in terms of its soliton solution for the first time.
基金supported by the High-level Talent Research Start-up Project Funding of Henan Academy of Sciences(Project No.241827012)the National Natural Science Foundation of China(Grant Nos.U22A6005 and 62271450)+1 种基金the National Key Research and Development Program of China(Grant Nos.2021YFA1301502,2024YFA1408701,and 2024YFA1408403)the Synergetic Extreme Condition User Facility(SECUF,https://cstr.cn/31123.02.SECUF)。
文摘The precise control of wrinkles and strain gradients in nanofilm is of significant interest due to their profound influence on electronic band structures and spin states.Here,we employ ultrafast electron diffraction(UED)to study the picosecond-scale dynamics of laser-induced bending in 2H-MoTe2 thin films.
基金supported by the National Natural Science Foundation of China(Grant No.12175316).
文摘Phase transitions,as one of the most intriguing phenomena in nature,are divided into first-order phase transitions(FOPTs)and continuous ones in current classification.While the latter shows striking phenomena of scaling and universality,the former has recently also been demonstrated to exhibit scaling and universal behavior within a mesoscopic,coarse-grained Landau-Ginzburg theory.Here we apply this theory to a microscopic model-the paradigmatic Ising model,which undergoes FOPTs between two ordered phases below its critical temperature-and unambiguously demonstrate universal scaling behavior in such FOPTs.These results open the door for extending the theory to other microscopic FOPT systems and experimentally testing them to systematically uncover their scaling and universal behavior.
基金supported by the National Natural Science Foundation of China(Grant Nos.62174016,12474047,12204202,and 11974355)the Basic Research Program of Jiangsu(Grant No.BK20220679)+1 种基金the Fund for Shanxi“1331Project”the Research Project Supported by Shanxi Scholarship Council of China.
文摘The presence of a van Hove singularity(vHS)at the Fermi level can trigger magnetic instability by mediating a spontaneous transition from paramagnetic to magnetically ordered states.While electrostatic doping(typically achieved via ionic gating)to shift the vHS to the Fermi level provides a general mechanism for engineering such magnetism,its volatile nature often leads to the collapse of induced states upon gate field removal.Here,a novel scheme is presented for non-volatile magnetic control by utilizing ferroelectric heterostructures to achieve reversible magnetism switching.Using two-dimensional VSiN_(3),a nonmagnetic material with Mexican-hat electronic band dispersions hosting vHSs,as a prototype,it is preliminarily demonstrated that both electron and hole doping can robustly induce magnetism.Further,by interfacing VSiN_(3)with ferroelectric Sc_(2)CO_(2),reversible switching of its magnetic state via polarization-driven heterointerfacial charge transfer is achieved.This mechanism enables a dynamic transition between insulating and half-metallic phases in VSiN_(3),establishing a pathway to design multiferroic tunnel junctions with giant tunneling electroresistance or magnetoresistance.This work bridges non-volatile ferroelectric control with vHS-enhanced magnetism,opening opportunities for energy-efficient and high-performance spintronic devices and non-volatile memory devices.
基金supported by the National Natural Science Foundation of China(Nos.22162014 and U24A2044).
文摘Anion exchange membrane fuel cells(AEMFCs),regarded as a promising alternative to proton exchange membrane fuel cells(PEMFCs),have garnered increasing attention because of their cost-effectiveness by using the non-noble metal catalysts and hydrocarbon-based ionomers as membrane[1].However,despite of extensive researches on non-noble metal catalysts such as Co[2].
文摘Two dimensional parabolic stability equations (PSE) are numerically solved using expansions in orthogonal functions in the normal direction.The Chebyshev polynomials approximation,which is a very useful form of orthogonal expansions, is applied to solving parabolic stability equations. It is shown that results of great accuracy are effectively obtained.The availability of using Chebyshev approximations in parabolic stability equations is confirmed.
基金Supported by the Talents Foundation of Hunan Agricultural University(11yj12)the Foundation of Pre-State Key Laboratory for Germplasm Innovation and Resource Utilization of Crops(11KFXM03)the National Natural Science Foundation of China(31000722)~~
文摘As rapeseed is a major oil crop with high quality vegetable oil and feed protein in China and the two-dimensional gel electrophoresis （2-DE） is an efficient technique for investigating protein expression, this paper reviews the innovations in 2-DE and its application in the studies of rapeseed. We conclude that 2-DE has provided much valuable information on rapeseed, and it will do more for rapeseed proteomic research in the near future with the technology innovations.
文摘The experimental study of vertical jet in a two dimensional fluidized bed is presented. The time series of vertical jet penetration depth are acquired by image processing. The fluctuation of jet which is studied by means of Hurst's analysis becomes weaker with increase in jet velocity, fluidization number, particle diameter and static bed height. They are found that the signal is persistent and the fractal dimensional of vertical jet is between 1.19 and 1.64.
文摘Coherent exciton-phonon coupling in CdSe/ZnS nanocrystals have been investigated by temperature-dependent two-dimensional electronic spectroscopy （2DES） measurements. Benefiting from the ability of 2DES to dissect assembles in nanocrystal films, we have dearly identified experimental evidences of coherent coupling between exciton and phonon in CdSe/ZnS nanocrystals. In time domain, 2DES signals of excitonic transitions beat at a frequency resonant to a longitudinal optical phonon mode; in energy domain, phonon side bands are distinct at both Stokes and anti-Stokes sides. When temperature increases, phonon-induced exciton dephasing is observed with dramatic broadening of homogeneous linewidth. The results suggest exciton-phonon coupling is essential in elucidating the quantum dynamics of excitonic transitions in semiconductor nanocrystals.
