Self-diffraction appears when the strong laser goes through two-dimensional material suspension,and this spatial self-phase modulation(SPPM)phenomenon can be used to measure nonlinear optical parameters and achieve op...Self-diffraction appears when the strong laser goes through two-dimensional material suspension,and this spatial self-phase modulation(SPPM)phenomenon can be used to measure nonlinear optical parameters and achieve optical switch.At present,the mechanism of SPPM is still ambiguous.The debate mainly focuses on whether the phenomenon is caused by the nonlinear refractive index of the two-dimensional material or the thermal effect of the laser.The lack of theory limits the dimension of the phase modulation to the radius of the diffraction ring and the vertical imbalance.Therefore,it is urgent to establish a unified and universal SSPM theoretical system of two-dimensional material.展开更多
Waveguide-integrated optical modulators are indispensable for on-chip optical interconnects and optical computing.To cope with the ever-increasing amount of data being generated and consumed,ultrafast waveguide-integr...Waveguide-integrated optical modulators are indispensable for on-chip optical interconnects and optical computing.To cope with the ever-increasing amount of data being generated and consumed,ultrafast waveguide-integrated optical modulators with low energy consumption are highly demanded.In recent years,two-dimensional(2D)materials have attracted a lot of attention and have provided tremendous opportunities for the development of high-performance waveguide-integrated optical modulators because of their extraordinary optoelectronic properties and versatile compatibility.This paper reviews the state-of-the-art waveguide-integrated optical modulators with 2D materials,providing researchers with the developing trends in the field and allowing them to identify existing challenges and promising potential solutions.First,the concept and fundamental mechanisms of optical modulation with 2D materials are summarized.Second,a review of waveguide-integrated optical modulators employing electro-optic,all-optic,and thermo-optic effects is provided.Finally,the challenges and perspectives of waveguide-integrated modulators with 2D materials are discussed.展开更多
Automatic modulation recognition(AMR)of radiation source signals is a research focus in the field of cognitive radio.However,the AMR of radiation source signals at low SNRs still faces a great challenge.Therefore,the ...Automatic modulation recognition(AMR)of radiation source signals is a research focus in the field of cognitive radio.However,the AMR of radiation source signals at low SNRs still faces a great challenge.Therefore,the AMR method of radiation source signals based on two-dimensional data matrix and improved residual neural network is proposed in this paper.First,the time series of the radiation source signals are reconstructed into two-dimensional data matrix,which greatly simplifies the signal preprocessing process.Second,the depthwise convolution and large-size convolutional kernels based residual neural network(DLRNet)is proposed to improve the feature extraction capability of the AMR model.Finally,the model performs feature extraction and classification on the two-dimensional data matrix to obtain the recognition vector that represents the signal modulation type.Theoretical analysis and simulation results show that the AMR method based on two-dimensional data matrix and improved residual network can significantly improve the accuracy of the AMR method.The recognition accuracy of the proposed method maintains a high level greater than 90% even at -14 dB SNR.展开更多
Proposed is a two-dimensional(2D)spectrum analysis system for acquiring the statistical information of radioactive particles on two dimensions,i.e.energy and time.Based on pulse width modulation readout circuit,such a...Proposed is a two-dimensional(2D)spectrum analysis system for acquiring the statistical information of radioactive particles on two dimensions,i.e.energy and time.Based on pulse width modulation readout circuit,such a system with 4-channels is designed,which converts the radiation signal into a rectangular pulse signal with pulse width modulated.The pulse width,occurrence time,and pulse count of the rectangular pulses are measured simultaneously with digital counters,so that the 2D spectra on energy and time of the radioactive particles can be obtained efficiently based on bi-parameter statistical analysis.A prototype of this 2D system is tested with gamma rays from 241Am isotopes,from which both the correlated 2D spectra and the independent spectra on energy and time are obtained.The energy spectra of four channels shows all characteristic peaks of 241Am gamma rays,among which the full-energy peak at 59.5keV exhibits energy resolution of about 5-6%,suggesting a good energy resolution and channel uniformity of the system.The regression of the time spectra of the characteristic peaks can give the time constants of each characteristic peak,revealing the time characteristics of the nuclear reactions in the radiative source.展开更多
Two-dimensional(2D)superconductors have attracted significant research interest due to their promising potential applications in optoelectronic and microelectronic devices.Herein,we employ first-principles calculation...Two-dimensional(2D)superconductors have attracted significant research interest due to their promising potential applications in optoelectronic and microelectronic devices.Herein,we employ first-principles calculations to predicted a new 2D conventional superconductor,Tc_(2)B_(2),demonstrating its stable structural configuration.Remarkably,under biaxial strain,the superconducting transition temperature(T_(c))of Tc_(2)B_(2)demonstrates a significant enhancement,achieving 19.5 K under 3%compressive strain and 9.2 K under 11%tensile strain.Our study reveals that strain-induced modifications in Fermi surface topology significantly enhance the Fermi surface nesting effect,which amplifies electron–phonon coupling interactions and consequently elevates Tc.Additionally,the presence of the Lifshitz transition results in a more pronounced rise in Tc under compressive strain compared to tensile strain.These insights offer important theoretical guidance for designing 2D superconductors with high-Tc through strain modulation.展开更多
With appropriate geometry configuration, helicopter- borne rotating synthetic aperture radar （ROSAR） can break through the limitations of monostatic synthetic aperture radar （SAR） on forward-looking imaging. With ...With appropriate geometry configuration, helicopter- borne rotating synthetic aperture radar （ROSAR） can break through the limitations of monostatic synthetic aperture radar （SAR） on forward-looking imaging. With this capability, ROSAR has extensive potential applications, such as self-navigation and self-landing. Moreover, it has many advantages if combined with the frequency modulated continuous wave （FMCW） technology. A novel geometric configuration and an imaging algorithm for helicopter-borne FMCW-ROSAR are proposed. Firstly, by per- forming the equivalent phase center principle, the separated trans- mitting and receiving antenna system is equalized to the case of system configuration with antenna for both transmitting and receiving signals. Based on this, the accurate two-dimensional spectrum is obtained and the Doppler frequency shift effect in- duced by the continuous motion of the platform during the long pulse duration is compensated. Next, the impacts of the velocity approximation error on the imaging algorithm are analyzed in de- tail, and the system parameters selection and resolution analysis are presented. The well-focused SAR image is then obtained by using the improved Omega-K algorithm incorporating the accurate compensation method for the velocity approximation error. FJnally, correctness of the analysis and effectiveness of the proposed al- gorithm are demonstrated through simulation results.展开更多
Stochastic resonance system is subject to the restriction of small frequency parameter in weak signal detection,in order to solve this problem,a frequency modulated weak signal detection method based on stochastic res...Stochastic resonance system is subject to the restriction of small frequency parameter in weak signal detection,in order to solve this problem,a frequency modulated weak signal detection method based on stochastic resonance and genetic algorithm is presented in this paper. The frequency limit of stochastic resonance is eliminated by introducing carrier signal,which is multiplied with the measured signal to be injected in the stochastic resonance system,meanwhile,using genetic algorithm to optimize the carrier signal frequency,which determine the generated difference-frequency signal in the lowfrequency range,so as to achieve the stochastic resonance weak signal detection. Results showthat the proposed method is feasible and effective,which can significantly improve the output SNR of stochastic resonance,in addition,the system has the better self-adaptability,according to the operation result and output phenomenon,the unknown frequency of the signal to be measured can be obtained,so as to realize the weak signal detection of arbitrary frequency.展开更多
The generation characteristics of nonlinear optical signals and their multi-dimensional modulation at micro-nano scale have become a prominent research area in nanophotonics,and also the key to developing various nove...The generation characteristics of nonlinear optical signals and their multi-dimensional modulation at micro-nano scale have become a prominent research area in nanophotonics,and also the key to developing various novel nonlinear photonics devices.In recent years,the demand for higher nonlinear conversion efficiency and device integration has led to the rapid progress of hybrid nonlinear metasurfaces composed of nanostructures and nonlinear materials.As a joint platform of stable wavefront modulation,nonlinear metasurface and efficient frequency conversion,hybrid nonlinear metasurfaces offer a splendid opportunity for developing the next-generation of multipurpose flat-optics devices.This article provides a comprehensive review of recent advances in hybrid nonlinear metasurfaces for light-field modulation.The advantages of hybrid systems are discussed from the perspectives of multifunctional light-field modulation,valleytronic modulation,and quantum technologies.Finally,the remaining challenges of hybrid metasurfaces are summarized and future developments are also prospected.展开更多
Due to the manifestation of fascinating physical phenomena and materials science, two-dimensional（2D） materials have recently attracted enormous research interest with respect to the fields of electronics and optoel...Due to the manifestation of fascinating physical phenomena and materials science, two-dimensional（2D） materials have recently attracted enormous research interest with respect to the fields of electronics and optoelectronics.There have been in-depth investigations of the nonlinear properties with respect to saturable absorption, and many 2D materials show potential application in optical switches for passive pulsed lasers. However, the Eigen band-gap determines the responding wavelength band and constrains the applications. In this paper, based on band-gap engineering, some different types of 2D broadband saturable absorbers are reviewed in detail, including molybdenum disulfide（MoS2）, vanadium dioxide（VO2）, graphene, and the Bi2Se3 topological insulator. The results suggest that the band-gap modification should play important roles in 2D broadband saturable materials and can provide some inspiration for the exploration and design of 2D nanodevices.展开更多
Two-dimensional transition metal dichalcogenides(TMDs)have shown great potential for application in the next generation of electronics and optoelectronics due to their atomically thin thickness,tunable band gap,and st...Two-dimensional transition metal dichalcogenides(TMDs)have shown great potential for application in the next generation of electronics and optoelectronics due to their atomically thin thickness,tunable band gap,and strong light-matter interaction.However,their practical application is still limited by challenges such as the constraints of high-temperature synthesis processes,compatibility issues of p-type/n-type doping strategies,and insufficient nanoscale patterning accuracy.Plasma treatment has become a key technology to break through these bottlenecks with its unique advantages such as low-temperature operation capability,generation of highly active reactive species and precise controllability of multiple parameters.This review comprehensively reviews the latest progress in plasma engineering of TMDs(MoS_(2),WS_(2),WSe_(2),etc.)based on a systematic“fundamental process-property modulation-device innovation”framework.The key plasma technologies are highlighted:plasma-enhanced chemical vapor deposition(PECVD)for low-temperature growth,bidirectional doping achieved through active species regulation,atomic layer precision etching,and defect engineering.The regulation mechanism of plasma on the intrinsic properties of materials is systematically analyzed,including electronic structure modification,optical property optimization(such as photoluminescence enhancement)and structural feature evolution.It then reveals how plasma technology promotes device innovation:achieving customizable structures(p-n junctions,sub-10 nanometer channels),optimizing interface properties(reducing contact resistance,integrating high-k dielectrics),and significantly improving the performance of gas sensors,photodetectors and neuromorphic computing systems.Finally,this article looks forward to future research directions,emphasizing that plasma technology is a versatile and indispensable platform for promoting TMDs towards practical applications.展开更多
Multiple quantum well spatial light modulators with 128×128 array in 38μm pitch are fabricated using two pproaches, one with an attachment of an optical substrate and another one without. These two fabrication p...Multiple quantum well spatial light modulators with 128×128 array in 38μm pitch are fabricated using two pproaches, one with an attachment of an optical substrate and another one without. These two fabrication processes are described and compared.展开更多
Two-dimensional(2D)materials have attracted considerable research interest,leading to significant advances in energy applications in recent years,such as lithium batteries,catalysis,electronics,and thermoelectrics,owi...Two-dimensional(2D)materials have attracted considerable research interest,leading to significant advances in energy applications in recent years,such as lithium batteries,catalysis,electronics,and thermoelectrics,owing to their rich controllable properties and excellent performances.Recently,pressure has been successfully employed as an effective method for property modulation of 2D materials,through tuning electronic orbitals and bonding patterns.In this review,we summarize recent progresses in the pressure-driven property modulations and elucidate the underlying mechanism of the pressure modulation of 2D materials.Further,we identify the remaining challenges and opportunities in this new,vibrant area of research for energy conversion and utilization.Among the different property modulation strategies,the in situ application of high pressure is systematically identified as a promising knob for 2D materials.This review is expected to inspire further research on the fundamental understanding and practical applications of high-pressure modulation in 2D materials.展开更多
Doping of semiconductors,i.e.,accurately modulating the charge carrier type and concentration in a controllable manner,is a key technology foundation for modern electronics and optoelectronics.However,the conventional...Doping of semiconductors,i.e.,accurately modulating the charge carrier type and concentration in a controllable manner,is a key technology foundation for modern electronics and optoelectronics.However,the conventional doping technologies widely utilized in silicon industry,such as ion implantation and thermal diffusion,always fail when applied to two-dimensional(2D)materials with atomically-thin nature.Surface charge transfer doping(SCTD)is emerging as an effective and non-destructive doping technique to provide reliable doping capability for 2D materials,in particular 2D semiconductors.Herein,we summarize the recent advances and developments on the SCTD of 2D semiconductors and its application in electronic and optoelectronic devices.The underlying mechanism of STCD processes on 2D semiconductors is briefly introduced.Its impact on tuning the fundamental properties of various 2D systems is highlighted.We particularly emphasize on the SCTD-enabled high-performance 2D functional devices.Finally,the challenges and opportunities for the future development of SCTD are discussed.展开更多
The field of two-dimensional(2D)nanomaterial-based cancer immunotherapy combines research from multiple subdisciplines of material science,nano-chemistry,in particular nanobiological interactions,immunology,and medici...The field of two-dimensional(2D)nanomaterial-based cancer immunotherapy combines research from multiple subdisciplines of material science,nano-chemistry,in particular nanobiological interactions,immunology,and medicinal chemistry.Most importantly,the"biological identity"of nanomaterials governed by bio-molecular corona in terms of bimolecular types,relative abundance,and conformation at the nanomaterial surface is now believed to influence blood circulation time,biodistribution,immune response,cellular uptake,and intracellular trafficking.A better understanding of nano-bio interactions can improve utilization of 2D nano-architectures for cancer immunotherapy and immunotheranostics,allowing them to be adapted or modified to treat other immune dysregulation syndromes including autoimmune diseases or inflammation,infection,tissue regeneration,and transplantation.The manuscript reviews the biological interactions and immunotherapeutic applications of 2D nanomaterials,including understanding their interactions with biological molecules of the immune system,summarizes and prospects the applications of 2D nanomaterials in cancer immunotherapy.展开更多
Two-dimensional(2D)layered materials have attracted extensive research interest in the field of high-performance photodetection due to their high carrier mobility,tunable bandgap,stability,other excellent properties.H...Two-dimensional(2D)layered materials have attracted extensive research interest in the field of high-performance photodetection due to their high carrier mobility,tunable bandgap,stability,other excellent properties.Herein,we propose a gate-tunable,high-performance,self-driving,wide detection range phototransistor based on a 2D PtSe_(2)on silicon-oninsulator(SOI).Benefiting from the strong built-in electric field of the PtSe_(2)/Si heterostructure,the phototransistor has a fast response time(rise/fall time)of 36.7/32.6μs.The PtSe_(2)/Si phototransistor exhibits excellent photodetection performance over a broad spectral range from ultraviolet to near-infrared,including a responsivity of 1.07 A/W and a specific detectivity of 6.60×10^(9)Jones under 808 nm illumination at zero gate voltage.The responsivity and specific detectivity of PtSe_(2)/Si phototransistor at 5 V gate voltage are increased to 13.85 A/W and 1.90×10^(10) Jones under 808 nm illumination.Furthermore,the fabricated PtSe_(2)/Si phototransistor array shows excellent uniformity,reproducibility,long-term stability in terms of photoresponse performance with negligible variation between pixel cells.The architecture of present PtSe_(2)/Si on SOI platform paves a new way of a general strategy to realize high-performance photodetectors by combining the advantages of both 2D materials and conventional semiconductors which is compatible with current Si-complementary metal oxide semiconductor(CMOS)process.展开更多
In this paper,two-dimensional electron gas（2DEG） regions in AlGaN/GaN high electron mobility transistors（HEMTs） are realized by doping partial silicon into the AlGaN layer for the first time.A new electric field p...In this paper,two-dimensional electron gas（2DEG） regions in AlGaN/GaN high electron mobility transistors（HEMTs） are realized by doping partial silicon into the AlGaN layer for the first time.A new electric field peak is introduced along the interface between the AlGaN and GaN buffer by the electric field modulation effect due to partial silicon positive charge.The high electric field near the gate for the complete silicon doping structure is effectively decreased,which makes the surface electric field uniform.The high electric field peak near the drain results from the potential difference between the surface and the depletion regions.Simulated breakdown curves that are the same as the test results are obtained for the first time by introducing an acceptor-like trap into the N-type GaN buffer.The proposed structure with partial silicon doping is better than the structure with complete silicon doping and conventional structures with the electric field plate near the drain.The breakdown voltage is improved from 296 V for the conventional structure to 400 V for the proposed one resulting from the uniform surface electric field.展开更多
Two-dimensional(2D)antiferromagnetic(AFM)skyrmions are free from stray magnetic field and skyrmion Hall effect,and can be driven by a small current density up to a high speed,desirable for low-power spintronic applica...Two-dimensional(2D)antiferromagnetic(AFM)skyrmions are free from stray magnetic field and skyrmion Hall effect,and can be driven by a small current density up to a high speed,desirable for low-power spintronic applications.However,most 2D AFM skyrmions are realized in complex heterostructured materials,which impedes the dense integration of spintronic devices.Here,we propose that 2D AFM skyrmions can be achieved in ruthenium tetrafluoride(RuF_(4))monolayer using hybrid functional theory combined with atomistic spin dynamics simulations.Our study indicates that 2D RuF_(4)is dynamically stable and its nondegenerate vibration modes in optical branches are either Raman or infrared active.Furthermore,2D RuF_(4)acts as an indirect bandgap semiconductor with an out-of-plane AFM state.Notably,the presence of a weak Dzyaloshinskii-Moriya interaction in 2D RuF_(4)leads to a spin spiral ground state at low temperatures,enabling the formation of AFM skyrmions with possible length modulation by an external magnetic field.Our results give insight into 2D RuF_(4)and may provide an intriguing platform for 2D AFM skyrmion-based spintronic applications.展开更多
This work investigates the dynamics of modulated waves in a coupled nonlinear LC transmission line. By means of a method based on the semi-discrete limit and in suitably scaled coordinates, we derive the two-dimension...This work investigates the dynamics of modulated waves in a coupled nonlinear LC transmission line. By means of a method based on the semi-discrete limit and in suitably scaled coordinates, we derive the two-dimensional NLS equation governing the propagation of slowly modulated waves in the network. The exact transverse solution is found and the analytical criteria of stability of this solution are derived. The condition for which the network can exhibit modulational instability is also determined. The exactness of this analytical analysis is confirmed by numerical simulations performed on the exact equation of the network.展开更多
Two-dimensional(2D)magnetic semiconductors have emerged as promising materials for next-generation nanoelectronic and spintronic devices,owing to their unique coupling of electronic and magnetic properties.CrSBr,a qua...Two-dimensional(2D)magnetic semiconductors have emerged as promising materials for next-generation nanoelectronic and spintronic devices,owing to their unique coupling of electronic and magnetic properties.CrSBr,a quasi-2D magnetic semiconductor,offers a versatile platform for exploring coupled electronic and magnetic phenomena in low-dimensional systems.Here,we systematically investigate the surface work function of CrSBr nanosheets using scanning Kelvin probe microscopy(SKPM),revealing a nonlinear dependence on thickness and a thermally tunable,reversible behavior.Furthermore,a CrSBr-based 2D field-effect transistor(FET)demonstrates that such thermal modulation of the work function effectively alters the Schottky barrier height,directly impacting charge injection.Density functional theory(DFT)calculations reveal the layer-and magnetism-dependent nature of the work function in few-layer CrSBr.This work highlights the importance of work function engineering in CrSBr and provides a foundation for its application in magnetoelectric coupling,spintronic devices,and van der Waals electronics.展开更多
Non-layered two-dimensional materials(NL2DMs)have emerged as a promising complement to layered 2D materials,offering unique properties derived from their isotropic bonding and structural diversity.However,their synthe...Non-layered two-dimensional materials(NL2DMs)have emerged as a promising complement to layered 2D materials,offering unique properties derived from their isotropic bonding and structural diversity.However,their synthesis is still facing significant challenges due to the lack of intrinsic anisotropic growth driving force.This review comprehensively outlines strategies for chemical vapor deposition(CVD)-based synthesis of NL2DMs,demonstrating how integrated thermodynamic and kinetic control enables precise thickness and morphology modulation.We also analyze the existing challenges and propose future research directions.This systematic framework paves the way for engineering NL2DMs growth with customized functionalities for next-generation optoelectronics,energy storage,and catalysis.展开更多
基金Project(6187031976)supported by the National Natural Science Foundation of China
文摘Self-diffraction appears when the strong laser goes through two-dimensional material suspension,and this spatial self-phase modulation(SPPM)phenomenon can be used to measure nonlinear optical parameters and achieve optical switch.At present,the mechanism of SPPM is still ambiguous.The debate mainly focuses on whether the phenomenon is caused by the nonlinear refractive index of the two-dimensional material or the thermal effect of the laser.The lack of theory limits the dimension of the phase modulation to the radius of the diffraction ring and the vertical imbalance.Therefore,it is urgent to establish a unified and universal SSPM theoretical system of two-dimensional material.
基金funding support from the National Major Research and Development Program(2019YFB2203603)the National Science Fund for Distinguished Young Scholars(61725503)+2 种基金the National Natural Science Foundation of China(NSFC)(62275273,11804387,and 91950205)the China Postdoctoral Science Foundation(2020M681847)the Zhejiang Provincial Natural Science Foundation(LZ18F050001).
文摘Waveguide-integrated optical modulators are indispensable for on-chip optical interconnects and optical computing.To cope with the ever-increasing amount of data being generated and consumed,ultrafast waveguide-integrated optical modulators with low energy consumption are highly demanded.In recent years,two-dimensional(2D)materials have attracted a lot of attention and have provided tremendous opportunities for the development of high-performance waveguide-integrated optical modulators because of their extraordinary optoelectronic properties and versatile compatibility.This paper reviews the state-of-the-art waveguide-integrated optical modulators with 2D materials,providing researchers with the developing trends in the field and allowing them to identify existing challenges and promising potential solutions.First,the concept and fundamental mechanisms of optical modulation with 2D materials are summarized.Second,a review of waveguide-integrated optical modulators employing electro-optic,all-optic,and thermo-optic effects is provided.Finally,the challenges and perspectives of waveguide-integrated modulators with 2D materials are discussed.
基金National Natural Science Foundation of China under Grant No.61973037China Postdoctoral Science Foundation under Grant No.2022M720419。
文摘Automatic modulation recognition(AMR)of radiation source signals is a research focus in the field of cognitive radio.However,the AMR of radiation source signals at low SNRs still faces a great challenge.Therefore,the AMR method of radiation source signals based on two-dimensional data matrix and improved residual neural network is proposed in this paper.First,the time series of the radiation source signals are reconstructed into two-dimensional data matrix,which greatly simplifies the signal preprocessing process.Second,the depthwise convolution and large-size convolutional kernels based residual neural network(DLRNet)is proposed to improve the feature extraction capability of the AMR model.Finally,the model performs feature extraction and classification on the two-dimensional data matrix to obtain the recognition vector that represents the signal modulation type.Theoretical analysis and simulation results show that the AMR method based on two-dimensional data matrix and improved residual network can significantly improve the accuracy of the AMR method.The recognition accuracy of the proposed method maintains a high level greater than 90% even at -14 dB SNR.
基金supported by the National Natural Science Foundation of China(Grant No.61274048)the National Science Associated Foundation of China(Grant No.10876044)
文摘Proposed is a two-dimensional(2D)spectrum analysis system for acquiring the statistical information of radioactive particles on two dimensions,i.e.energy and time.Based on pulse width modulation readout circuit,such a system with 4-channels is designed,which converts the radiation signal into a rectangular pulse signal with pulse width modulated.The pulse width,occurrence time,and pulse count of the rectangular pulses are measured simultaneously with digital counters,so that the 2D spectra on energy and time of the radioactive particles can be obtained efficiently based on bi-parameter statistical analysis.A prototype of this 2D system is tested with gamma rays from 241Am isotopes,from which both the correlated 2D spectra and the independent spectra on energy and time are obtained.The energy spectra of four channels shows all characteristic peaks of 241Am gamma rays,among which the full-energy peak at 59.5keV exhibits energy resolution of about 5-6%,suggesting a good energy resolution and channel uniformity of the system.The regression of the time spectra of the characteristic peaks can give the time constants of each characteristic peak,revealing the time characteristics of the nuclear reactions in the radiative source.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12274169,12122405,and 52072188)the National Key Research and Development Program of China(Grant No.2022YFA1402304)+1 种基金the Program for Science and Technology Innovation Team in Zhejiang Province,China(Grant No.2021R01004)the Fundamental Research Funds for the Central Universities.
文摘Two-dimensional(2D)superconductors have attracted significant research interest due to their promising potential applications in optoelectronic and microelectronic devices.Herein,we employ first-principles calculations to predicted a new 2D conventional superconductor,Tc_(2)B_(2),demonstrating its stable structural configuration.Remarkably,under biaxial strain,the superconducting transition temperature(T_(c))of Tc_(2)B_(2)demonstrates a significant enhancement,achieving 19.5 K under 3%compressive strain and 9.2 K under 11%tensile strain.Our study reveals that strain-induced modifications in Fermi surface topology significantly enhance the Fermi surface nesting effect,which amplifies electron–phonon coupling interactions and consequently elevates Tc.Additionally,the presence of the Lifshitz transition results in a more pronounced rise in Tc under compressive strain compared to tensile strain.These insights offer important theoretical guidance for designing 2D superconductors with high-Tc through strain modulation.
基金supported by the National Basic Research Program of China(2011CB707001)the Fundamental Research Funds for the Central Universities(106112015CDJXY500001CDJZR165505)
文摘With appropriate geometry configuration, helicopter- borne rotating synthetic aperture radar （ROSAR） can break through the limitations of monostatic synthetic aperture radar （SAR） on forward-looking imaging. With this capability, ROSAR has extensive potential applications, such as self-navigation and self-landing. Moreover, it has many advantages if combined with the frequency modulated continuous wave （FMCW） technology. A novel geometric configuration and an imaging algorithm for helicopter-borne FMCW-ROSAR are proposed. Firstly, by per- forming the equivalent phase center principle, the separated trans- mitting and receiving antenna system is equalized to the case of system configuration with antenna for both transmitting and receiving signals. Based on this, the accurate two-dimensional spectrum is obtained and the Doppler frequency shift effect in- duced by the continuous motion of the platform during the long pulse duration is compensated. Next, the impacts of the velocity approximation error on the imaging algorithm are analyzed in de- tail, and the system parameters selection and resolution analysis are presented. The well-focused SAR image is then obtained by using the improved Omega-K algorithm incorporating the accurate compensation method for the velocity approximation error. FJnally, correctness of the analysis and effectiveness of the proposed al- gorithm are demonstrated through simulation results.
基金supported by the National Natural Science Foundation of China (Grant No. 61072133)the Production,Learning and Research Joint Innovation Program of Jiangsu Province,China (Grant Nos. BY2013007-02,SBY201120033)+2 种基金the Industrialization of Research Findings Promotion Program of Institution of Higher Education of Jiangsu Province,China (Grant No. JHB2011-15)the advantage discipline platform "information and Communication Engineering" of Jiangsu Province,Chinathe "Summit of the Six Top Talents" Program of Jiangsu Province,China
文摘Stochastic resonance system is subject to the restriction of small frequency parameter in weak signal detection,in order to solve this problem,a frequency modulated weak signal detection method based on stochastic resonance and genetic algorithm is presented in this paper. The frequency limit of stochastic resonance is eliminated by introducing carrier signal,which is multiplied with the measured signal to be injected in the stochastic resonance system,meanwhile,using genetic algorithm to optimize the carrier signal frequency,which determine the generated difference-frequency signal in the lowfrequency range,so as to achieve the stochastic resonance weak signal detection. Results showthat the proposed method is feasible and effective,which can significantly improve the output SNR of stochastic resonance,in addition,the system has the better self-adaptability,according to the operation result and output phenomenon,the unknown frequency of the signal to be measured can be obtained,so as to realize the weak signal detection of arbitrary frequency.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12274157,12274334,91850113,12021004,and 11904271)the Natural Science Foundation of Hubei Province of China(Grant No.2023AFA076)the Basic and Applied Basic Research Major Program of Guangdong Province of China(Grant No.2019B030302003)。
文摘The generation characteristics of nonlinear optical signals and their multi-dimensional modulation at micro-nano scale have become a prominent research area in nanophotonics,and also the key to developing various novel nonlinear photonics devices.In recent years,the demand for higher nonlinear conversion efficiency and device integration has led to the rapid progress of hybrid nonlinear metasurfaces composed of nanostructures and nonlinear materials.As a joint platform of stable wavefront modulation,nonlinear metasurface and efficient frequency conversion,hybrid nonlinear metasurfaces offer a splendid opportunity for developing the next-generation of multipurpose flat-optics devices.This article provides a comprehensive review of recent advances in hybrid nonlinear metasurfaces for light-field modulation.The advantages of hybrid systems are discussed from the perspectives of multifunctional light-field modulation,valleytronic modulation,and quantum technologies.Finally,the remaining challenges of hybrid metasurfaces are summarized and future developments are also prospected.
基金supported by the National Natural Science Foundation of China (Nos. 51025210 and 51422205)the China Scholarship Council in 2014 (No. 201406220045)
文摘Due to the manifestation of fascinating physical phenomena and materials science, two-dimensional（2D） materials have recently attracted enormous research interest with respect to the fields of electronics and optoelectronics.There have been in-depth investigations of the nonlinear properties with respect to saturable absorption, and many 2D materials show potential application in optical switches for passive pulsed lasers. However, the Eigen band-gap determines the responding wavelength band and constrains the applications. In this paper, based on band-gap engineering, some different types of 2D broadband saturable absorbers are reviewed in detail, including molybdenum disulfide（MoS2）, vanadium dioxide（VO2）, graphene, and the Bi2Se3 topological insulator. The results suggest that the band-gap modification should play important roles in 2D broadband saturable materials and can provide some inspiration for the exploration and design of 2D nanodevices.
基金supported by the National Science Foundation of China(Nos.62304151,62204170,and 62474124)the Natural Science Foundation of Tianjin(No.24JCQNJC00520)+3 种基金the China Postdoctoral Science Foundation(No.2023M742585)the Open Project of State Key Laboratory of Transducer Technology(No.SKT2208)the open research of Songshan Lake Materials Laboratory(No.2023SLABFK07)the State Key Laboratory of Fluid Power and Mechatronic Systems(No.GZKF-202327).
文摘Two-dimensional transition metal dichalcogenides(TMDs)have shown great potential for application in the next generation of electronics and optoelectronics due to their atomically thin thickness,tunable band gap,and strong light-matter interaction.However,their practical application is still limited by challenges such as the constraints of high-temperature synthesis processes,compatibility issues of p-type/n-type doping strategies,and insufficient nanoscale patterning accuracy.Plasma treatment has become a key technology to break through these bottlenecks with its unique advantages such as low-temperature operation capability,generation of highly active reactive species and precise controllability of multiple parameters.This review comprehensively reviews the latest progress in plasma engineering of TMDs(MoS_(2),WS_(2),WSe_(2),etc.)based on a systematic“fundamental process-property modulation-device innovation”framework.The key plasma technologies are highlighted:plasma-enhanced chemical vapor deposition(PECVD)for low-temperature growth,bidirectional doping achieved through active species regulation,atomic layer precision etching,and defect engineering.The regulation mechanism of plasma on the intrinsic properties of materials is systematically analyzed,including electronic structure modification,optical property optimization(such as photoluminescence enhancement)and structural feature evolution.It then reveals how plasma technology promotes device innovation:achieving customizable structures(p-n junctions,sub-10 nanometer channels),optimizing interface properties(reducing contact resistance,integrating high-k dielectrics),and significantly improving the performance of gas sensors,photodetectors and neuromorphic computing systems.Finally,this article looks forward to future research directions,emphasizing that plasma technology is a versatile and indispensable platform for promoting TMDs towards practical applications.
文摘Multiple quantum well spatial light modulators with 128×128 array in 38μm pitch are fabricated using two pproaches, one with an attachment of an optical substrate and another one without. These two fabrication processes are described and compared.
基金The authors acknowledge the micro-fabrication center of National Laboratory of Solid State Microstructures(NLSSM)for technique supportProf.Jia Zhu acknowledges the support from the XPLORER PRIZE+3 种基金This work is jointly supported by the National Key Research and Development Program of China(No.2021YFA140070)the National Natural Science Foundation of China(Nos.61735008,51925204,12022403)Excellent Research Program of Nanjing University(ZYJH005)Carbon Peaking and Carbon Neutrality Science and Technology Innovation Fund of Jiangsu Province(BK20220035).
文摘Two-dimensional(2D)materials have attracted considerable research interest,leading to significant advances in energy applications in recent years,such as lithium batteries,catalysis,electronics,and thermoelectrics,owing to their rich controllable properties and excellent performances.Recently,pressure has been successfully employed as an effective method for property modulation of 2D materials,through tuning electronic orbitals and bonding patterns.In this review,we summarize recent progresses in the pressure-driven property modulations and elucidate the underlying mechanism of the pressure modulation of 2D materials.Further,we identify the remaining challenges and opportunities in this new,vibrant area of research for energy conversion and utilization.Among the different property modulation strategies,the in situ application of high pressure is systematically identified as a promising knob for 2D materials.This review is expected to inspire further research on the fundamental understanding and practical applications of high-pressure modulation in 2D materials.
基金the financial support from Natural Science Foundation of Jiangsu Province(No.BK20170005)the National Natural Science Foundation of China(No.21872100)+1 种基金Singapore MOE Grants MOE2019-T2-1-002 and R143-000-A43-114,Fundamental Research Foundation of Shenzhen(Nos.JCYJ20190808152607389 and JCYJ20170817100405375)Shenzhen Peacock Plan(No.KQTD2016053112042971).
文摘Doping of semiconductors,i.e.,accurately modulating the charge carrier type and concentration in a controllable manner,is a key technology foundation for modern electronics and optoelectronics.However,the conventional doping technologies widely utilized in silicon industry,such as ion implantation and thermal diffusion,always fail when applied to two-dimensional(2D)materials with atomically-thin nature.Surface charge transfer doping(SCTD)is emerging as an effective and non-destructive doping technique to provide reliable doping capability for 2D materials,in particular 2D semiconductors.Herein,we summarize the recent advances and developments on the SCTD of 2D semiconductors and its application in electronic and optoelectronic devices.The underlying mechanism of STCD processes on 2D semiconductors is briefly introduced.Its impact on tuning the fundamental properties of various 2D systems is highlighted.We particularly emphasize on the SCTD-enabled high-performance 2D functional devices.Finally,the challenges and opportunities for the future development of SCTD are discussed.
基金support from the US METAvivor Early Career Investigator Award(No.2018A020560,Wei Tao,USA)Harvard Medical School/Brigham and Women’s Hospital Department of Anesthesiology-Basic Scientist Grant(No.2420 BPA075,Wei Tao,USA)+3 种基金Center for Nanomedicine Research Fund(NO.2019A014810,Wei Tao,USA)supported by The Hundred Talents Program,China(75110-18841227)from Sun Yat-Sen University,Guangzhou,Chinathe Guangdong Basic and Applied Basic Research Foundation(2019A1515110326,China)supported by the China postdoctoral science foundation(2019M663060)。
文摘The field of two-dimensional(2D)nanomaterial-based cancer immunotherapy combines research from multiple subdisciplines of material science,nano-chemistry,in particular nanobiological interactions,immunology,and medicinal chemistry.Most importantly,the"biological identity"of nanomaterials governed by bio-molecular corona in terms of bimolecular types,relative abundance,and conformation at the nanomaterial surface is now believed to influence blood circulation time,biodistribution,immune response,cellular uptake,and intracellular trafficking.A better understanding of nano-bio interactions can improve utilization of 2D nano-architectures for cancer immunotherapy and immunotheranostics,allowing them to be adapted or modified to treat other immune dysregulation syndromes including autoimmune diseases or inflammation,infection,tissue regeneration,and transplantation.The manuscript reviews the biological interactions and immunotherapeutic applications of 2D nanomaterials,including understanding their interactions with biological molecules of the immune system,summarizes and prospects the applications of 2D nanomaterials in cancer immunotherapy.
基金the National Natural Science Foundation of China(Nos.62090030/62090031,51872257,51672244,and 62274145)the National Key R&D Program of China(No.2021YFA1200502)+1 种基金the Natural Science Foundation of Zhejiang Province(No.LZ20F040001)the Zhejiang Province Key R&D Pprogram(No.2020C01120).
文摘Two-dimensional(2D)layered materials have attracted extensive research interest in the field of high-performance photodetection due to their high carrier mobility,tunable bandgap,stability,other excellent properties.Herein,we propose a gate-tunable,high-performance,self-driving,wide detection range phototransistor based on a 2D PtSe_(2)on silicon-oninsulator(SOI).Benefiting from the strong built-in electric field of the PtSe_(2)/Si heterostructure,the phototransistor has a fast response time(rise/fall time)of 36.7/32.6μs.The PtSe_(2)/Si phototransistor exhibits excellent photodetection performance over a broad spectral range from ultraviolet to near-infrared,including a responsivity of 1.07 A/W and a specific detectivity of 6.60×10^(9)Jones under 808 nm illumination at zero gate voltage.The responsivity and specific detectivity of PtSe_(2)/Si phototransistor at 5 V gate voltage are increased to 13.85 A/W and 1.90×10^(10) Jones under 808 nm illumination.Furthermore,the fabricated PtSe_(2)/Si phototransistor array shows excellent uniformity,reproducibility,long-term stability in terms of photoresponse performance with negligible variation between pixel cells.The architecture of present PtSe_(2)/Si on SOI platform paves a new way of a general strategy to realize high-performance photodetectors by combining the advantages of both 2D materials and conventional semiconductors which is compatible with current Si-complementary metal oxide semiconductor(CMOS)process.
基金Project supported by the Young Scientists Fund of the National Natural Science Foundation of China (Grant No. 61106076)
文摘In this paper,two-dimensional electron gas（2DEG） regions in AlGaN/GaN high electron mobility transistors（HEMTs） are realized by doping partial silicon into the AlGaN layer for the first time.A new electric field peak is introduced along the interface between the AlGaN and GaN buffer by the electric field modulation effect due to partial silicon positive charge.The high electric field near the gate for the complete silicon doping structure is effectively decreased,which makes the surface electric field uniform.The high electric field peak near the drain results from the potential difference between the surface and the depletion regions.Simulated breakdown curves that are the same as the test results are obtained for the first time by introducing an acceptor-like trap into the N-type GaN buffer.The proposed structure with partial silicon doping is better than the structure with complete silicon doping and conventional structures with the electric field plate near the drain.The breakdown voltage is improved from 296 V for the conventional structure to 400 V for the proposed one resulting from the uniform surface electric field.
基金supported by the National Key Research and Development Program of China(MOST)(2022YFA1405100)the National Natural Science Foundation of China(NSFC)(52172272)the Scientific Research Foundation of CUIT(KYTZ202172).
文摘Two-dimensional(2D)antiferromagnetic(AFM)skyrmions are free from stray magnetic field and skyrmion Hall effect,and can be driven by a small current density up to a high speed,desirable for low-power spintronic applications.However,most 2D AFM skyrmions are realized in complex heterostructured materials,which impedes the dense integration of spintronic devices.Here,we propose that 2D AFM skyrmions can be achieved in ruthenium tetrafluoride(RuF_(4))monolayer using hybrid functional theory combined with atomistic spin dynamics simulations.Our study indicates that 2D RuF_(4)is dynamically stable and its nondegenerate vibration modes in optical branches are either Raman or infrared active.Furthermore,2D RuF_(4)acts as an indirect bandgap semiconductor with an out-of-plane AFM state.Notably,the presence of a weak Dzyaloshinskii-Moriya interaction in 2D RuF_(4)leads to a spin spiral ground state at low temperatures,enabling the formation of AFM skyrmions with possible length modulation by an external magnetic field.Our results give insight into 2D RuF_(4)and may provide an intriguing platform for 2D AFM skyrmion-based spintronic applications.
基金grateful to the Journal of Modern Physics for financial support in publication.
文摘This work investigates the dynamics of modulated waves in a coupled nonlinear LC transmission line. By means of a method based on the semi-discrete limit and in suitably scaled coordinates, we derive the two-dimensional NLS equation governing the propagation of slowly modulated waves in the network. The exact transverse solution is found and the analytical criteria of stability of this solution are derived. The condition for which the network can exhibit modulational instability is also determined. The exactness of this analytical analysis is confirmed by numerical simulations performed on the exact equation of the network.
基金support from the National Key Research and Development Project (Grant No. 2024YFA1408802)the Key Research and Development Program of Shaanxi (Grant No. 2025GH-YBXM-050)+7 种基金the National Natural Science Foundation of China (Grant Nos. 12204294, 62304069, 52202186, and 12104352)the China National Postdoctoral Programme for Innovative Talents (No. BX20230281)the Natural Science Basic Research Program of Shaanxi (Program No. 2023JC-XJ01)Ningxia Key Research and Development Program (Grant No. 2020BEB04042)Xidian University Specially Funded Project for Interdisciplinary Exploration (Nos. TZJH2024064 and TZJH2024053)the Fundamental Research Funds for the Central Universitiesthe Innovation Fund of Xidian Universitythe China Postdoctoral Science Foundation (Certifcate No. 2024M752520)
文摘Two-dimensional(2D)magnetic semiconductors have emerged as promising materials for next-generation nanoelectronic and spintronic devices,owing to their unique coupling of electronic and magnetic properties.CrSBr,a quasi-2D magnetic semiconductor,offers a versatile platform for exploring coupled electronic and magnetic phenomena in low-dimensional systems.Here,we systematically investigate the surface work function of CrSBr nanosheets using scanning Kelvin probe microscopy(SKPM),revealing a nonlinear dependence on thickness and a thermally tunable,reversible behavior.Furthermore,a CrSBr-based 2D field-effect transistor(FET)demonstrates that such thermal modulation of the work function effectively alters the Schottky barrier height,directly impacting charge injection.Density functional theory(DFT)calculations reveal the layer-and magnetism-dependent nature of the work function in few-layer CrSBr.This work highlights the importance of work function engineering in CrSBr and provides a foundation for its application in magnetoelectric coupling,spintronic devices,and van der Waals electronics.
基金supported by the National Natural Science Foundation of China(Nos.12474163,52202161 and 12034002)State Key Laboratory for Advanced Metals and Materials(No.2025-S02).
文摘Non-layered two-dimensional materials(NL2DMs)have emerged as a promising complement to layered 2D materials,offering unique properties derived from their isotropic bonding and structural diversity.However,their synthesis is still facing significant challenges due to the lack of intrinsic anisotropic growth driving force.This review comprehensively outlines strategies for chemical vapor deposition(CVD)-based synthesis of NL2DMs,demonstrating how integrated thermodynamic and kinetic control enables precise thickness and morphology modulation.We also analyze the existing challenges and propose future research directions.This systematic framework paves the way for engineering NL2DMs growth with customized functionalities for next-generation optoelectronics,energy storage,and catalysis.
