The Hodgkin–Huxley model assumes independent ion channel activation,although mutual interactions are common in biological systems.This raises the problem why neurons would favor independent over cooperative channel a...The Hodgkin–Huxley model assumes independent ion channel activation,although mutual interactions are common in biological systems.This raises the problem why neurons would favor independent over cooperative channel activation.In this study,we evaluate how cooperative activation of sodium channels affects the neuron’s information processing and energy consumption.Simulations of the stochastic Hodgkin–Huxley model with cooperative activation of sodium channels show that,while cooperative activation enhances neuronal information processing capacity,it greatly increases the neuron’s energy consumption.As a result,cooperative activation of sodium channel degrades the energy efficiency for neuronal information processing.This discovery improves our understanding of the design principles for neural systems,and may provide insights into future designs of the neuromorphic computing devices as well as systematic understanding of pathological mechanisms for neural diseases.展开更多
The two-component cold atom systems with anisotropic hopping amplitudes can be phenomenologically described by a two-dimensional Ising-XY coupled model with spatial anisotropy.At low temperatures,theoretical predictio...The two-component cold atom systems with anisotropic hopping amplitudes can be phenomenologically described by a two-dimensional Ising-XY coupled model with spatial anisotropy.At low temperatures,theoretical predictions[Phys.Rev.A 72053604(2005)]and[arXiv:0706.1609]indicate the existence of a topological ordered phase characterized by Ising and XY disorder but with 2XY ordering.However,due to ergodic difficulties faced by Monte Carlo methods at low temperatures,this topological phase has not been numerically explored.We propose a linear cluster updating Monte Carlo method,which flips spins without rejection in the anisotropy limit but does not change the energy.Using this scheme and conventional Monte Carlo methods,we succeed in revealing the nature of topological phases with half-vortices and domain walls.In the constructed global phase diagram,Ising and XY-type transitions are very close to each other and differ significantly from the schematic phase diagram reported earlier.We also propose and explore a wide range of quantities,including magnetism,superfluidity,specific heat,susceptibility,and even percolation susceptibility,and obtain consistent and reliable results.Furthermore,we observed first-order transitions characterized by common intersection points in magnetizations for different system sizes,as opposed to the conventional phase transition where Binder cumulants of various sizes share common intersections.The critical exponents of different types of phase transitions are reasonably fitted.The results are useful to help cold atom experiments explore the half-vortex topological phase.展开更多
Metal halide perovskites have recently emerged as promising candidates for the next generation of X-ray detectors due to their excellent optoelectronic properties.Especially,two-dimensional(2D)perovskites afford many ...Metal halide perovskites have recently emerged as promising candidates for the next generation of X-ray detectors due to their excellent optoelectronic properties.Especially,two-dimensional(2D)perovskites afford many distinct properties,including remarkable structural diversity,high generation energy,and balanced large exciton binding energy.With the advantages of 2D materials and perovskites,it successfully reduces the decomposition and phase transition of perovskite and effectively suppresses ion migration.Meanwhile,the existence of a high hydrophobic spacer can block water molecules,thus making 2D perovskite obtain excellent stability.All of these advantages have attracted much attention in the field of X-ray detection.This review introduces the classification of 2D halide perovskites,summarizes the synthesis technology and performance characteristics of 2D perovskite X-ray direct detector,and briefly discusses the application of 2D perovskite in scintillators.Finally,this review also emphasizes the key challenges faced by 2D perovskite X-ray detectors in practical application and presents our views on its future development.展开更多
Although seemingly disparate,high-energy nuclear physics(HENP)and machine learning(ML)have begun to merge in the last few years,yielding interesting results.It is worthy to raise the profile of utilizing this novel mi...Although seemingly disparate,high-energy nuclear physics(HENP)and machine learning(ML)have begun to merge in the last few years,yielding interesting results.It is worthy to raise the profile of utilizing this novel mindset from ML in HENP,to help interested readers see the breadth of activities around this intersection.The aim of this mini-review is to inform the community of the current status and present an overview of the application of ML to HENP.From different aspects and using examples,we examine how scientific questions involving HENP can be answered using ML.展开更多
Considering the R&D for upgrading the K^(0)_(L) andμdetectors in the Belle II experiment using a scintillator and silicon pho-tomultiplier(SiPM),we designed a compact high-speed and low-noise preamplifier.The pre...Considering the R&D for upgrading the K^(0)_(L) andμdetectors in the Belle II experiment using a scintillator and silicon pho-tomultiplier(SiPM),we designed a compact high-speed and low-noise preamplifier.The preamplifier demonstrated a good gain stability,bandwidth of 426 MHz,baseline noise level ofσ≈0.6 mV,dynamic range of up to170 mV of the input signal amplitude,good time resolution of 20 ps,and it can be comprehensively applied to SiPMs.Adopting pole-zero-cancelation in the preamplifier reduces both the rise and fall times of the SiPM signal,which can significantly improve the time resolution and reduce the pile-up when using a large SiPM or an array of SiPMs.Various combinations of the preamplifier and several types of SiPMs demonstrated time resolutions better than 50 ps for most cases;when the number of detected photons was larger than 60,a time resolution of approximately 25 ps was achieved.展开更多
Kinetically constrained spin systems are toy models of supercooled liquids and amorphous solids. In this perspective,we revisit the prototypical Fredrickson–Andersen(FA) kinetically constrained model from the viewpoi...Kinetically constrained spin systems are toy models of supercooled liquids and amorphous solids. In this perspective,we revisit the prototypical Fredrickson–Andersen(FA) kinetically constrained model from the viewpoint of K-core combinatorial optimization. Each kinetic cluster of the FA system, containing all the mutually visitable microscopic occupation configurations, is exactly the solution space of a specific instance of the K-core attack problem. The whole set of different jammed occupation patterns of the FA system is the configuration space of an equilibrium K-core problem. Based on recent theoretical results achieved on the K-core attack and equilibrium K-core problems, we discuss the thermodynamic spin glass phase transitions and the maximum occupation density of the fully unfrozen FA kinetic cluster, and the minimum occupation density and extreme vulnerability of the partially frozen(jammed) kinetic clusters. The equivalence between K-core attack and the fully unfrozen FA kinetic cluster also implies a new way of sampling K-core attack solutions.展开更多
We theoretically investigate the Ruderman–Kittel–Kasuya–Yosida(RKKY) interaction in helical higher-order topological insulators(HOTIs), revealing distinct behaviors mediated by hinge and Dirac-type bulk carriers. O...We theoretically investigate the Ruderman–Kittel–Kasuya–Yosida(RKKY) interaction in helical higher-order topological insulators(HOTIs), revealing distinct behaviors mediated by hinge and Dirac-type bulk carriers. Our findings show that hinge-mediated interactions consist of Heisenberg, Ising, and Dzyaloshinskii–Moriya(DM) terms, exhibiting a decay with impurity spacing z and oscillations with Fermi energy εF. These interactions demonstrate ferromagnetic behaviors for the Heisenberg and Ising terms and alternating behavior for the DM term. In contrast, bulk-mediated interactions include Heisenberg, twisted Ising, and DM terms, with a conventional cubic oscillating decay. This study highlights the nuanced interplay between hinge and bulk RKKY interactions in HOTIs, offering insights into designs of next-generation quantum devices based on HOTIs.展开更多
We study the above-threshold ionization(ATI)process of atoms exposed to fundamental and high-frequency lasers with arbitrary ellipticity by applying the frequency-domain theory.It is found that the angular-resolved AT...We study the above-threshold ionization(ATI)process of atoms exposed to fundamental and high-frequency lasers with arbitrary ellipticity by applying the frequency-domain theory.It is found that the angular-resolved ATI spectrum is sensitive to ellipticities of two lasers and emitted angles of the photoelectron.Particularly for the photon energy of the highfrequency laser more than atomic ionization potential,the width of plateau tends to a constant with increasing ellipticity of fundamental field,the dip structure disappears with increasing ellipticity of the high-frequency field.With the help of the quantum channel analysis,it is shown that the angular distribution depends mainly on the ellipticity of high-frequency field in the case that its frequency is high.Moreover,one can see that the maximal and minimal energies in quantum numerical results are in good agreement with the classical prediction.Our investigation may provide theoretical support for experimental research on polarization control of ionization in elliptically polarized two-color laser fields.展开更多
Jet quenching parameter q is essential for characterizing the interaction strength between jet partons and nuclear matter.Based on the quark-meson model,we develop a new framework for calculating q at finite chemical ...Jet quenching parameter q is essential for characterizing the interaction strength between jet partons and nuclear matter.Based on the quark-meson model,we develop a new framework for calculating q at finite chemical potentials,in which q is related to the spectral function of the chiral order parameter.展开更多
We investigate the nature of the strong coupling constant and related physics.Through the analysis of accumulated experimental data around the world,we employ the ability of machine learning to unravel its physical la...We investigate the nature of the strong coupling constant and related physics.Through the analysis of accumulated experimental data around the world,we employ the ability of machine learning to unravel its physical laws.The result of our efforts is a formula that captures the expansive panorama of the distribution of the strong coupling constant across the entire energy range.展开更多
Ultra-peripheral heavy-ion collisions(UPCs)offer unique opportunities to study processes under strong electromagnetic fields.In these collisions,highly charged fast-moving ions carry strong electromagnetic fields that...Ultra-peripheral heavy-ion collisions(UPCs)offer unique opportunities to study processes under strong electromagnetic fields.In these collisions,highly charged fast-moving ions carry strong electromagnetic fields that can be effectively treated as photon fluxes.The exchange of photons can induce photonuclear and two-photon interactions and excite ions.This excitation of the ions results in Coulomb dissociation with the emission of photons,neutrons,and other particles.Additionally,the electromagnetic fields generated by the ions can be sufficiently strong to enforce mutual interactions between the two colliding ions.Consequently,the two colliding ions experience an electromagnetic force that pushes them in opposite directions,causing a back-to-back correlation in the emitted neutrons.Using a Monte Carlo simulation,we qualitatively demonstrate that the above electromagnetic effect is large enough to be observed in UPCs,which would provide a clear means to study strong electromagnetic fields and their effects.展开更多
The recently discovered,extremely proton-rich nuclide 18 Mg exhibits ground-state decay via two sequential two-proton(2p)emissions through the intermediate nucleus,16Ne.This study investigates the structure and the in...The recently discovered,extremely proton-rich nuclide 18 Mg exhibits ground-state decay via two sequential two-proton(2p)emissions through the intermediate nucleus,16Ne.This study investigates the structure and the initial 2p decay mechanism of^(18)Mgby examining the density and correlations of the valence protons using a three-body Gamow coupled-channel method.The results show that the ground state of^(18)Mgis significantly influenced by the continuum,resulting in a significant s-wave component.However,based on the current framework,this does not lead to a significant deviation in mirror symmetry in either the structure or spectroscopy of the 18Mg-18C pair.Additionally,the time evolution analysis of the^(18)Mgground state suggests a simultaneous 2p emission during the first step of decay.The observed nucleon-nucleon correlations align with those of the light-mass 2p emitters,indicating a consistent decay behavior within this nuclear region.展开更多
Deeply subwavelength lasers(or nanolasers)are highly demanded for compact on-chip bioimaging and sensing at the nanoscale.One of the main obstacles for the development of single-particle nanolasers with all three dime...Deeply subwavelength lasers(or nanolasers)are highly demanded for compact on-chip bioimaging and sensing at the nanoscale.One of the main obstacles for the development of single-particle nanolasers with all three dimensions shorter than the emitting wavelength in the visible range is the high lasing thresholds and the resulting overheating.Here we ex-ploit exciton-polariton condensation and mirror-image Mie modes in a cuboid CsPbBr3 nanoparticle to achieve coherent emission at the visible wavelength of around 0.53μm from its ultra-small(≈0.007μm3 or≈λ3/20)semiconductor nanocav-ity.The polaritonic nature of the emission from the nanocavity localized in all three dimensions is proven by direct com-parison with corresponding one-dimensional and two-dimensional waveguiding systems with similar material parameters.Such a deeply subwavelength nanolaser is enabled not only by the high values for exciton binding energy(≈35 meV),re-fractive index(>2.5 at low temperature),and luminescence quantum yield of CsPbBr3,but also by the optimization of po-laritons condensation on the Mie resonances with quality factors improved by the metallic substrate.Moreover,the key parameters for optimal lasing conditions are intermode free spectral range and phonons spectrum in CsPbBr3,which govern polaritons condensation path.Such chemically synthesized colloidal CsPbBr3 nanolasers can be potentially de-posited on arbitrary surfaces,which makes them a versatile tool for integration with various on-chip systems.展开更多
We discuss the Casimir force of Maxwell-Chern-Simons A belian gauge tield in different limits between twoparallel ideal conducting wires by using the Feynman path integral method.
Antiferromagnetic materials are exciting quantum materials with rich physics and great potential for applications.On the other hand, an accurate and efficient theoretical method is highly demanded for determining crit...Antiferromagnetic materials are exciting quantum materials with rich physics and great potential for applications.On the other hand, an accurate and efficient theoretical method is highly demanded for determining critical transition temperatures, Néel temperatures, of antiferromagnetic materials. The powerful graph neural networks(GNNs) that succeed in predicting material properties lose their advantage in predicting magnetic properties due to the small dataset of magnetic materials, while conventional machine learning models heavily depend on the quality of material descriptors. We propose a new strategy to extract high-level material representations by utilizing self-supervised training of GNNs on large-scale unlabeled datasets. According to the dimensional reduction analysis, we find that the learned knowledge about elements and magnetism transfers to the generated atomic vector representations. Compared with popular manually constructed descriptors and crystal graph convolutional neural networks, self-supervised material representations can help us to obtain a more accurate and efficient model for Néel temperatures, and the trained model can successfully predict high Néel temperature antiferromagnetic materials. Our self-supervised GNN may serve as a universal pre-training framework for various material properties.展开更多
Using the asymptotic iteration method, we obtain the S-wave solution for a short-range three-parameter central potential with 1/r singularity and with a non-orbital barrier. To the best of our knowledge, this is the f...Using the asymptotic iteration method, we obtain the S-wave solution for a short-range three-parameter central potential with 1/r singularity and with a non-orbital barrier. To the best of our knowledge, this is the first attempt at calculating the energy spectrum for this potential, which was introduced by H. Bahlouli and A. D. Alhaidari and for which they obtained the “potential parameter spectrum”. Our results are also independently verified using a direct method of diagonalizing the Hamiltonian matrix in the J-matrix basis.展开更多
The interaction kernel in the Bethe-Salpeter (B-S) equation for quark-antiquark bound states is derivedfrom B-S equations satisfied by the quark-antiquark four-point Green's function. The latter equations are esta...The interaction kernel in the Bethe-Salpeter (B-S) equation for quark-antiquark bound states is derivedfrom B-S equations satisfied by the quark-antiquark four-point Green's function. The latter equations are establishedbased on the equations of motion obeyed by the quark and antiquark propagators, the four-point Green's function andsome other kinds of Green's functions, which follow directly from the QCD generating functional. The derived B-Skernel is given by a closed and explicit expression which contains only a few types of Green's functions. This expressionis not only convenient for perturbative calculations, but also applicable for nonperturbative investigations. Since thekernel contains all the interactions taking place in the quark-antiquark bound states, it actually appears to be the mostsuitable starting point of studying the QCD nonperturbative effect and quark confinement.展开更多
The interaction kernel in the Bethe-Salpeter equation for quark-antiquark bound states is derived newly from QCD in the case where the quark and the antiquark are of different flavors. The technique of the derivation ...The interaction kernel in the Bethe-Salpeter equation for quark-antiquark bound states is derived newly from QCD in the case where the quark and the antiquark are of different flavors. The technique of the derivation is the usage of the irreducible decomposition of the Green's functions involved in the Bethe-Salpeter equation satisfied by the quark-antiquark four-point Green's function. The interaction kernel derived is given a closed and explicit expression which shows a specific structure of the kernel since the kernel is represented in terms of the quark, antiquark and gluon propagators and some kinds of quark, antiquark and/or gluon three, four, five and six-point vertices. Therefore,the expression of the kernel is not only convenient for perturbative calculations, but also suitable for nonperturbative investigations.展开更多
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.lzujbky-2021-62)the Shanghai Municipal Science and Technology Major Project(Grant No.2018SHZDZX01)Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence(LCNBI)and ZJLab,and the National Natural Science Foundation of China(Grant No.12247101).
文摘The Hodgkin–Huxley model assumes independent ion channel activation,although mutual interactions are common in biological systems.This raises the problem why neurons would favor independent over cooperative channel activation.In this study,we evaluate how cooperative activation of sodium channels affects the neuron’s information processing and energy consumption.Simulations of the stochastic Hodgkin–Huxley model with cooperative activation of sodium channels show that,while cooperative activation enhances neuronal information processing capacity,it greatly increases the neuron’s energy consumption.As a result,cooperative activation of sodium channel degrades the energy efficiency for neuronal information processing.This discovery improves our understanding of the design principles for neural systems,and may provide insights into future designs of the neuromorphic computing devices as well as systematic understanding of pathological mechanisms for neural diseases.
基金Project supported by the Hefei National Research Center for Physical Sciences at the Microscale (Grant No.KF2021002)the Natural Science Foundation of Shanxi Province,China (Grant Nos.202303021221029 and 202103021224051)+2 种基金the National Natural Science Foundation of China (Grant Nos.11975024,12047503,and 12275263)the Anhui Provincial Supporting Program for Excellent Young Talents in Colleges and Universities (Grant No.gxyq ZD2019023)the National Key Research and Development Program of China (Grant No.2018YFA0306501)。
文摘The two-component cold atom systems with anisotropic hopping amplitudes can be phenomenologically described by a two-dimensional Ising-XY coupled model with spatial anisotropy.At low temperatures,theoretical predictions[Phys.Rev.A 72053604(2005)]and[arXiv:0706.1609]indicate the existence of a topological ordered phase characterized by Ising and XY disorder but with 2XY ordering.However,due to ergodic difficulties faced by Monte Carlo methods at low temperatures,this topological phase has not been numerically explored.We propose a linear cluster updating Monte Carlo method,which flips spins without rejection in the anisotropy limit but does not change the energy.Using this scheme and conventional Monte Carlo methods,we succeed in revealing the nature of topological phases with half-vortices and domain walls.In the constructed global phase diagram,Ising and XY-type transitions are very close to each other and differ significantly from the schematic phase diagram reported earlier.We also propose and explore a wide range of quantities,including magnetism,superfluidity,specific heat,susceptibility,and even percolation susceptibility,and obtain consistent and reliable results.Furthermore,we observed first-order transitions characterized by common intersection points in magnetizations for different system sizes,as opposed to the conventional phase transition where Binder cumulants of various sizes share common intersections.The critical exponents of different types of phase transitions are reasonably fitted.The results are useful to help cold atom experiments explore the half-vortex topological phase.
基金This work was funded by the National Natural Science Foundation of China(22279049 and 12247101)the Fundamental Research Funds for the Central Universities(lzujbky-2021-it31,lzujbky-2021-ct15 and lzujbky-2021-sp69)+1 种基金the calculation work was supported by Supercomputing Center of Lanzhou Universitythe Gansu Province Outstanding Doctoral Student Program(22JR5RA435).
文摘Metal halide perovskites have recently emerged as promising candidates for the next generation of X-ray detectors due to their excellent optoelectronic properties.Especially,two-dimensional(2D)perovskites afford many distinct properties,including remarkable structural diversity,high generation energy,and balanced large exciton binding energy.With the advantages of 2D materials and perovskites,it successfully reduces the decomposition and phase transition of perovskite and effectively suppresses ion migration.Meanwhile,the existence of a high hydrophobic spacer can block water molecules,thus making 2D perovskite obtain excellent stability.All of these advantages have attracted much attention in the field of X-ray detection.This review introduces the classification of 2D halide perovskites,summarizes the synthesis technology and performance characteristics of 2D perovskite X-ray direct detector,and briefly discusses the application of 2D perovskite in scintillators.Finally,this review also emphasizes the key challenges faced by 2D perovskite X-ray detectors in practical application and presents our views on its future development.
基金supported in part by the National Natural Science Foundation of China under contract Nos.11890714,12147101(Ma),12075098(Pang),12247107,12075007(Song)the Germany BMBF under the ErUM-Data project(Zhou)the Guangdong Major Project of Basic and Applied Basic Research No.2020B0301030008(Ma).
文摘Although seemingly disparate,high-energy nuclear physics(HENP)and machine learning(ML)have begun to merge in the last few years,yielding interesting results.It is worthy to raise the profile of utilizing this novel mindset from ML in HENP,to help interested readers see the breadth of activities around this intersection.The aim of this mini-review is to inform the community of the current status and present an overview of the application of ML to HENP.From different aspects and using examples,we examine how scientific questions involving HENP can be answered using ML.
基金This work was partially supported by the National Key R&D Program of China(No.2022YFA1601903)the National Natural Science Foundation of China(Nos.11925502,11961141003,and 12175041)the Strategic Priority Research Program of the CAS(No.XDB34030000).
文摘Considering the R&D for upgrading the K^(0)_(L) andμdetectors in the Belle II experiment using a scintillator and silicon pho-tomultiplier(SiPM),we designed a compact high-speed and low-noise preamplifier.The preamplifier demonstrated a good gain stability,bandwidth of 426 MHz,baseline noise level ofσ≈0.6 mV,dynamic range of up to170 mV of the input signal amplitude,good time resolution of 20 ps,and it can be comprehensively applied to SiPMs.Adopting pole-zero-cancelation in the preamplifier reduces both the rise and fall times of the SiPM signal,which can significantly improve the time resolution and reduce the pile-up when using a large SiPM or an array of SiPMs.Various combinations of the preamplifier and several types of SiPMs demonstrated time resolutions better than 50 ps for most cases;when the number of detected photons was larger than 60,a time resolution of approximately 25 ps was achieved.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 12247104 and 12047503)。
文摘Kinetically constrained spin systems are toy models of supercooled liquids and amorphous solids. In this perspective,we revisit the prototypical Fredrickson–Andersen(FA) kinetically constrained model from the viewpoint of K-core combinatorial optimization. Each kinetic cluster of the FA system, containing all the mutually visitable microscopic occupation configurations, is exactly the solution space of a specific instance of the K-core attack problem. The whole set of different jammed occupation patterns of the FA system is the configuration space of an equilibrium K-core problem. Based on recent theoretical results achieved on the K-core attack and equilibrium K-core problems, we discuss the thermodynamic spin glass phase transitions and the maximum occupation density of the fully unfrozen FA kinetic cluster, and the minimum occupation density and extreme vulnerability of the partially frozen(jammed) kinetic clusters. The equivalence between K-core attack and the fully unfrozen FA kinetic cluster also implies a new way of sampling K-core attack solutions.
基金supported by the research foundation of Institute for Advanced Sciences of CQUPT(Grant No.E011A2022328)。
文摘We theoretically investigate the Ruderman–Kittel–Kasuya–Yosida(RKKY) interaction in helical higher-order topological insulators(HOTIs), revealing distinct behaviors mediated by hinge and Dirac-type bulk carriers. Our findings show that hinge-mediated interactions consist of Heisenberg, Ising, and Dzyaloshinskii–Moriya(DM) terms, exhibiting a decay with impurity spacing z and oscillations with Fermi energy εF. These interactions demonstrate ferromagnetic behaviors for the Heisenberg and Ising terms and alternating behavior for the DM term. In contrast, bulk-mediated interactions include Heisenberg, twisted Ising, and DM terms, with a conventional cubic oscillating decay. This study highlights the nuanced interplay between hinge and bulk RKKY interactions in HOTIs, offering insights into designs of next-generation quantum devices based on HOTIs.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.12104285,12074240,12204135,12374260,12264013,12204136,92250303,and 12074418)the Guangdong Basicand Applied Basic Research Foundation (Grant No.2022A1515011742)+5 种基金the Special Scientific Research Program supported by the Shaanxi Education Department (Grant No.22JK0423)the Natural Science Basic Research Program of Shaanxi Province of China (Grant Nos.2023-JC-QN-0085 and 2023-JC-QN-0267)the Hainan Provincial Natural Science Foundation of China (Grant Nos.122CXTD504,123MS002,123QN179,123QN180,and 122QN217)the Sino-German Mobility Programme (Grant No.M-0031)the Xi’an Aeronautical Institute 2023 Innovation and Entrepreneurship Training Program for college students (Grant No.S202311736036)the Course Ideological and Political Education Program (Grant No.23ZLGC5030)。
文摘We study the above-threshold ionization(ATI)process of atoms exposed to fundamental and high-frequency lasers with arbitrary ellipticity by applying the frequency-domain theory.It is found that the angular-resolved ATI spectrum is sensitive to ellipticities of two lasers and emitted angles of the photoelectron.Particularly for the photon energy of the highfrequency laser more than atomic ionization potential,the width of plateau tends to a constant with increasing ellipticity of fundamental field,the dip structure disappears with increasing ellipticity of the high-frequency field.With the help of the quantum channel analysis,it is shown that the angular distribution depends mainly on the ellipticity of high-frequency field in the case that its frequency is high.Moreover,one can see that the maximal and minimal energies in quantum numerical results are in good agreement with the classical prediction.Our investigation may provide theoretical support for experimental research on polarization control of ionization in elliptically polarized two-color laser fields.
基金supported by the National Natural Science Foundation of China(Grant Nos.12105129,12175122,2021867,and 12247101)。
文摘Jet quenching parameter q is essential for characterizing the interaction strength between jet partons and nuclear matter.Based on the quark-meson model,we develop a new framework for calculating q at finite chemical potentials,in which q is related to the spectral function of the chiral order parameter.
基金supported by the National Natural Science Foundation of China(Grant Nos.12065014,12047501,12247101,and 12335001)the Natural Science Foundation of Gansu Province(Grant No.22JR5RA266)+5 种基金the West Light Foundation of Chinese Academy of Sciences(Grant No.21JR7RA201)supported by the China National Funds for Distinguished Young Scientists(Grant No.11825503)the National Key Research and Development Program of China(Grant No.2020YFA0406400)the 111 Project(Grant No.B20063)the fundamental Research Funds for the Central Universitiesthe Project for Top-Notch Innovative Talents of Gansu province。
文摘We investigate the nature of the strong coupling constant and related physics.Through the analysis of accumulated experimental data around the world,we employ the ability of machine learning to unravel its physical laws.The result of our efforts is a formula that captures the expansive panorama of the distribution of the strong coupling constant across the entire energy range.
基金This work is supported in part by the National Key Research and Development Program of China(Nos.2022YFA1604900)the Guangdong Major Project of Basic and Applied Basic Research(No.2020B0301030008)+3 种基金the National Natural Science Foundation of China(Nos.12275053,12025501,11890710,11890714,12147101,12075061,and 12225502)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB34030000)Shanghai National Science Foundation(No.20ZR1404100)STCSM(No.23590780100).
文摘Ultra-peripheral heavy-ion collisions(UPCs)offer unique opportunities to study processes under strong electromagnetic fields.In these collisions,highly charged fast-moving ions carry strong electromagnetic fields that can be effectively treated as photon fluxes.The exchange of photons can induce photonuclear and two-photon interactions and excite ions.This excitation of the ions results in Coulomb dissociation with the emission of photons,neutrons,and other particles.Additionally,the electromagnetic fields generated by the ions can be sufficiently strong to enforce mutual interactions between the two colliding ions.Consequently,the two colliding ions experience an electromagnetic force that pushes them in opposite directions,causing a back-to-back correlation in the emitted neutrons.Using a Monte Carlo simulation,we qualitatively demonstrate that the above electromagnetic effect is large enough to be observed in UPCs,which would provide a clear means to study strong electromagnetic fields and their effects.
基金the National Key Research and Development Program(MOST 2022YFA1602303 and MOST 2023YFA1606404)the National Natural Science Foundation of China(Nos.12347106,2147101,11925502,11935001 and 11961141003)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB34030000).
文摘The recently discovered,extremely proton-rich nuclide 18 Mg exhibits ground-state decay via two sequential two-proton(2p)emissions through the intermediate nucleus,16Ne.This study investigates the structure and the initial 2p decay mechanism of^(18)Mgby examining the density and correlations of the valence protons using a three-body Gamow coupled-channel method.The results show that the ground state of^(18)Mgis significantly influenced by the continuum,resulting in a significant s-wave component.However,based on the current framework,this does not lead to a significant deviation in mirror symmetry in either the structure or spectroscopy of the 18Mg-18C pair.Additionally,the time evolution analysis of the^(18)Mgground state suggests a simultaneous 2p emission during the first step of decay.The observed nucleon-nucleon correlations align with those of the light-mass 2p emitters,indicating a consistent decay behavior within this nuclear region.
基金supported by the Federal Program'Priority 2030'and NSFC(Project 62350610272)A.K.Samusev acknowledges Deutsche Forschungsgemeinschaft-project No.529710370。
文摘Deeply subwavelength lasers(or nanolasers)are highly demanded for compact on-chip bioimaging and sensing at the nanoscale.One of the main obstacles for the development of single-particle nanolasers with all three dimensions shorter than the emitting wavelength in the visible range is the high lasing thresholds and the resulting overheating.Here we ex-ploit exciton-polariton condensation and mirror-image Mie modes in a cuboid CsPbBr3 nanoparticle to achieve coherent emission at the visible wavelength of around 0.53μm from its ultra-small(≈0.007μm3 or≈λ3/20)semiconductor nanocav-ity.The polaritonic nature of the emission from the nanocavity localized in all three dimensions is proven by direct com-parison with corresponding one-dimensional and two-dimensional waveguiding systems with similar material parameters.Such a deeply subwavelength nanolaser is enabled not only by the high values for exciton binding energy(≈35 meV),re-fractive index(>2.5 at low temperature),and luminescence quantum yield of CsPbBr3,but also by the optimization of po-laritons condensation on the Mie resonances with quality factors improved by the metallic substrate.Moreover,the key parameters for optimal lasing conditions are intermode free spectral range and phonons spectrum in CsPbBr3,which govern polaritons condensation path.Such chemically synthesized colloidal CsPbBr3 nanolasers can be potentially de-posited on arbitrary surfaces,which makes them a versatile tool for integration with various on-chip systems.
基金supported by the National Key Research and Development Program of China(Grant No.2016YFA0600704)the National Natural Science Foundation of China(Grant No.41375104)
文摘We discuss the Casimir force of Maxwell-Chern-Simons A belian gauge tield in different limits between twoparallel ideal conducting wires by using the Feynman path integral method.
基金supported by the Scientific Research Program from Science and Technology Bureau of Chongqing City (Grant No. cstc2020jcyj-msxm X0684)the Science and Technology Research Program of Chongqing Municipal Education Commission (Grant No. KJQN202000639)in part by the National Natural Science Foundation of China (Grant No. 12147102)
文摘Antiferromagnetic materials are exciting quantum materials with rich physics and great potential for applications.On the other hand, an accurate and efficient theoretical method is highly demanded for determining critical transition temperatures, Néel temperatures, of antiferromagnetic materials. The powerful graph neural networks(GNNs) that succeed in predicting material properties lose their advantage in predicting magnetic properties due to the small dataset of magnetic materials, while conventional machine learning models heavily depend on the quality of material descriptors. We propose a new strategy to extract high-level material representations by utilizing self-supervised training of GNNs on large-scale unlabeled datasets. According to the dimensional reduction analysis, we find that the learned knowledge about elements and magnetism transfers to the generated atomic vector representations. Compared with popular manually constructed descriptors and crystal graph convolutional neural networks, self-supervised material representations can help us to obtain a more accurate and efficient model for Néel temperatures, and the trained model can successfully predict high Néel temperature antiferromagnetic materials. Our self-supervised GNN may serve as a universal pre-training framework for various material properties.
文摘Using the asymptotic iteration method, we obtain the S-wave solution for a short-range three-parameter central potential with 1/r singularity and with a non-orbital barrier. To the best of our knowledge, this is the first attempt at calculating the energy spectrum for this potential, which was introduced by H. Bahlouli and A. D. Alhaidari and for which they obtained the “potential parameter spectrum”. Our results are also independently verified using a direct method of diagonalizing the Hamiltonian matrix in the J-matrix basis.
基金国家自然科学基金,the Research Fund for the Doctoral Program of Higher Education of China
文摘The interaction kernel in the Bethe-Salpeter (B-S) equation for quark-antiquark bound states is derivedfrom B-S equations satisfied by the quark-antiquark four-point Green's function. The latter equations are establishedbased on the equations of motion obeyed by the quark and antiquark propagators, the four-point Green's function andsome other kinds of Green's functions, which follow directly from the QCD generating functional. The derived B-Skernel is given by a closed and explicit expression which contains only a few types of Green's functions. This expressionis not only convenient for perturbative calculations, but also applicable for nonperturbative investigations. Since thekernel contains all the interactions taking place in the quark-antiquark bound states, it actually appears to be the mostsuitable starting point of studying the QCD nonperturbative effect and quark confinement.
文摘The interaction kernel in the Bethe-Salpeter equation for quark-antiquark bound states is derived newly from QCD in the case where the quark and the antiquark are of different flavors. The technique of the derivation is the usage of the irreducible decomposition of the Green's functions involved in the Bethe-Salpeter equation satisfied by the quark-antiquark four-point Green's function. The interaction kernel derived is given a closed and explicit expression which shows a specific structure of the kernel since the kernel is represented in terms of the quark, antiquark and gluon propagators and some kinds of quark, antiquark and/or gluon three, four, five and six-point vertices. Therefore,the expression of the kernel is not only convenient for perturbative calculations, but also suitable for nonperturbative investigations.