检索结果-南通市图书馆

Exploring hidden-charm and hidden-strange hexaquark states from lattice QCD

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2024年第1期67卷 30-37页

作者： Hang Liu Jinchen He Liuming Liu Peng Sun Wei Wang Yi-Bo Yang Qi-An Zhang INPAC Key Laboratory for Particle Astrophysics and Cosmology(MOE)Shanghai Key Laboratory for Particle Physics and CosmologySchool of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Maryland Center for Fundamental physics Department of PhysicsUniversity of MarylandCollege ParkMaryland 20742USA institute of Modern physics Chinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China Department of physics and institute of theoretical physics Nanjing Normal UniversityNanjing 210023China Southern Center for Nuclear-Science Theory(SCNT) Institute of Modern PhysicsChinese Academy of SciencesHuizhou 516000China CAS Key Laboratory of theoretical physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Fundamental physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China International Centre for theoretical physics Asia-Pacific Beijing 100049/Hangzhou 310024China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China School of physics Beihang UniversityBeijing 102206China

Based on five different ensembles of newly generated(2+1)-flavor configurations with pion mass of approximately mπ■(140-310)MeV,we present a lattice analysis of hidden-charm and hidden-strange hexaquarks with the quark content■.The correlation matrices of two types of operators with JPC=0++,0-+,1++and 1--are simulated to extract the masses of the hexaquark candidates,which are subsequently extrapolated to the physical pion mass and continuum limit.The results indicate that ground state masses are below the■threshold and provide a characteristic signal for the experimental discovery of hexaquark candidates,which may enrich the versatile structure of multiquarks;moreover,it is an indispensable step to decipher the nonperturbative nature of the fundamental interactions of quarks and gluons.

关键词： quantum chromodynamics lattice QCD multiquark states

Is Yang-Mills theory unitary in fractional spacetime dimensions?

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2024年第7期67卷 59-64页

作者： Qingjun Jin Ke Ren Gang Yang Rui Yu Graduate School of China Academy of Engineering physics Beijing 100193China School of physics and Astronomy Sun Yat-Sen UniversityZhuhai 519082China CAS Key Laboratory of theoretical physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Fundamental physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China International Centre for theoretical physics Asia-Pacific Hangzhou 310024China School of Physical Science and Technology Inner Mongolia UniversityHohhot 010021China Beijing Computational Science Research Center Beijing 100193China

We present concrete evidence that Yang-Mills theory exhibits non-unitarity in non-integer spacetime dimensions.This violation of unitarity stems from evanescent operators that,while vanishing in four dimensions,are non-zero in general d dimensions.We demonstrate that these evanescent operators lead to the emergence of both negative-norm states and complex anomalous dimensions.

关键词： gauge field theories field theories in dimensions other than four renormalization

Electrodynamics with violations of Lorentz and U(1)gauge symmetries and their Hamiltonian structures

在线全文

学校读者我要写书评

暂无评论

Chinese physics C 2024年第6期48卷 45-57页

作者：杨秀鹏李瀑飞朱涛 institute for theoretical physics and Cosmology Zhejiang University of TechnologyHangzhou 310032China United Center for Gravitational Wave physics(UCGWP) Zhejiang University of TechnologyHangzhou 310032China

This study aims to investigate Lorentz/U(1)gauge symmetry-breaking electrodynamics in the framework of the standard-model extension and analyze the Hamiltonian structure for the theory with a specific dimension of Lorentz breaking operators.For this purpose,we consider a general quadratic action of the modified electrodynamics with Lorentz/gauge-breaking operators and calculate the number of independent components of the operators at different dimensions in gauge invariance and breaking.With this general action,we then analyze how Lorentz/gauge symmetry-breaking can change the Hamiltonian structure of the theories by considering Lorentz/gauge-breaking operators with dimension as examples.We show that the Lorentz-breaking operators with gauge invariance do not change the classes of the theory constrains and the number of physical degrees of freedom of the standard Maxwell electrodynamics.When U(1)gauge symmetry-breaking operators are present,the theories generally lack a first-class constraint and have one additional physical degree of freedom compared to the standard Maxwell electrodynamics.

关键词： standard model extension electrodynamics Lorentz violations

Combining thermal scanning probe lithography and dry etching for grayscale nanopattern amplification

在线全文

学校读者我要写书评

暂无评论

Microsystems & Nanoengineering 2024年第1期10卷 335-344页

作者： Berke Erbas Ana Conde-Rubio Xia Liu Joffrey Pernollet Zhenyu Wang Arnaud Bertsch Marcos Penedo Georg Fantner Mitali Banerjee Andras Kis Giovanni Boero Juergen Brugger Microsystems Laboratory École Polytechnique Fédérale de Lausanne(EPFL)Lausanne 1015Switzerland Center of MicroNanoTechnology(CMi) EPFLLausanne 1015Switzerland Laboratory of Nanoscale Electronics and Structures École Polytechnique Fédérale de Lausanne(EPFL)Lausanne 1015Switzerland Laboratory for Bio-and Nano-Instrumentation École Polytechnique Fédérale de Lausanne(EPFL)Lausanne 1015Switzerland Laboratory of Quantum physics Topology and CorrelationsÉcole Polytechnique Fédérale de Lausanne(EPFL)Lausanne 1015Switzerland present address:institute of Materials Science of Barcelona ICMAB-CSIC Campus UABBellaterra 08193Spain present address:School of Integrated Circuits and Electronics MIIT Key Laboratory for Low-Dimensional Quantum Structure and DevicesBeijing Institute of TechnologyBeijing 100081China

Grayscale structured surfaces with nanometer-scale features are used in a growing number of applications in optics and fluidics.Thermal scanning probe lithography achieves a lateral resolution below 10 nm and a vertical resolution below 1 nm,but its maximum depth in polymers is limited.Here,we present an innovative combination of nanowriting in thermal resist and plasma dry etching with substrate cooling,which achieves up to 10-fold amplification of polymer nanopatterns into SiO_(2) without proportionally increasing surface roughness.Sinusoidal nanopatterns in SiO_(2) with 400 nm pitch and 150 nm depth are fabricated free of shape distortion after dry etching.To exemplify the possible applications of the proposed method,grayscale dielectric nanostructures are used for scalable manufacturing through nanoimprint lithography and for strain nanoengineering of 2D materials.Such a method for aspect ratio amplification and smooth grayscale nanopatterning has the potential to find application in the fabrication of photonic and nanoelectronic devices.

关键词： lithography thermal pattern

Regulating the dopant clustering in LiZnAs-based diluted magnetic semiconductor

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese physics B 2024年第5期33卷 617-623页

作者：贾子航周波姜振益张小东 institute of Modern physics Northwest UniversityXi'an 710069China Shaanxi Key Laboratory for theoretical physics Frontiers Northwest UniversityXi'an 710069China Department of physics Chinese University of Hong KongHong Kong SARChina Beijing Computational Science Research Center Beijing 100193China

Tuning of the magnetic interaction plays the vital role in reducing the clustering of magnetic dopant in diluted magnetic semiconductors(DMS).Due to the not well understood magnetic mechanism and the interplay between different magnetic mechanisms,no efficient and universal tuning strategy is proposed at present.Here,the magnetic interactions and formation energies of isovalent-doped(Mn) and aliovalent(Cr)-doped LiZnAs are studied based on density functional theory(DFT).It is found that the dopant–dopant distance-dependent magnetic interaction is highly sensitive to the carrier concentration and carrier type and can only be explained by the interplay between two magnetic mechanisms,i.e.,superexchange and Zener’s p–d exchange model.Thus,the magnetic behavior and clustering of magnetic dopant can be tuned by the interplay between two magnetic mechanisms.The insensitivity of the tuning effect to U parameter suggests that our strategy could be universal to other DMS.

关键词： diluted magnetic semiconductor dopant distribution first-principles calculations

A versatile model with three-dimensional triangular lattice for unconventional transport and various topological effects

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第1期11卷 204-214页

作者： Jing-Yang You Gang Su Yuan Ping Feng Department of physics National University of Singapore Kavli institute for theoretical Sciences and CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences Centre for Advanced 2D Materials National University of Singapore

The finite Berry curvature in topological materials can induce many subtle phenomena, such as the anomalous Hall effect(AHE), spin Hall effect(SHE), anomalous Nernst effect(ANE), non-linear Hall effect(NLHE) and bulk photovoltaic effects. To explore these novel physics as well as their connection and coupling, a precise and effective model should be developed. Here, we propose such a versatile model—a 3D triangular lattice with alternating hopping parameters, which can yield various topological phases,including kagome bands, triply degenerate fermions, double Weyl semimetals and so on. We reveal that this special lattice can present unconventional transport due to its unique topological surface states and the aforementioned topological phenomena, such as AHE, ANE, NLHE and the topological photocurrent effect. In addition, we also provide a number of material candidates that have been synthesized experimentally with this lattice, and discuss two materials, including a non-magnetic triangular system for SHE, NLHE and the shift current, and a ferromagnetic triangular lattice for AHE and ANE. Our work provides an excellent platform, including both the model and materials, for the study of Berry-curvature-related physics.

关键词： three-dimensional triangular lattice different topological phases various topological effects Berry curvature

Acoustic Bilayer Gradient Metasurfaces for Perfect and Asymmetric Beam Splitting

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese physics Letters 2024年第1期41卷 39-50页

作者：权家琪孙宝印伏洋洋高雷徐亚东 institute of theoretical and Applied physics School of Physical Science and TechnologySoochow UniversitySuzhou 215006China College of physics Nanjing University of Aeronautics and Astronautics&Key Laboratory of Aerospace Information Materials and Physics(NUAA)MIITNanjing 211106China School of Optical and Electronic Information Suzhou City UniversitySuzhou 215104China

We experimentally and theoretically present a paradigm for the accurate bilayer design of gradient metasurfaces for wave beam manipulation,producing an extremely asymmetric splitting effect by simply tailoring the interlayer size.This concept arises from anomalous diffraction in phase gradient metasurfaces and the precise combination of the phase gradient in bilayer metasurfaces.Ensured by different diffraction routes in momentum space for incident beams from opposite directions,extremely asymmetric acoustic beam splitting can be generated in a robust way,as demonstrated in experiments through a designed bilayer system.Our work provides a novel approach and feasible platform for designing tunable devices to control wave propagation.

关键词： surfaces splitting asymmetric

High-order time-reversal symmetry breaking normal state

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2024年第3期67卷 136-148页

作者： Meng Zeng Lun-Hui Hu Hong-Ye Hu Yi-Zhuang You Congjun Wu Department of physics University of CaliforniaSan DiegoCalifornia 92093USA Department of physics Zhejiang UniversityHangzhou 310058China New Cornerstone Science Laboratory Department of PhysicsSchoolof ScienceWestlake UniversityHangzhou 30024China institute for theoretical Sciences Westlake UniversityHangzhou 310024China Key Laboratory for Quantum Materials of Zhejiang Province School of ScienceWestlake UniversityHangzhou 310024China institute of Natural Sciences Westlake Institute for Advanced StudyHangzhou 310024China

Spontaneous time-reversal symmetry breaking plays an important role in studying strongly correlated unconventional superconductors.When two superconducting gap functions with different symmetries compete,the relative phase channel(θ_(-)≡θ_(1)-θ_(2))exhibits an Ising-type Z_(2) symmetry due to the second order Josephson coupling,where θ_(1,2) are the phases of two gap functions.In contrast,the U(1) symmetry in the channel of θ_(+)≡(θ_(1)+θ_(2))/2 is intact.The phase locking,i.e.,ordering of θ_(-),can take place in the phase fluctuation regime before the onset of superconductivity,i.e.,when θ_(+) is disordered.If θ_(-) is pinned at ±π/2,then timereversal symmetry is broken in the normal state,otherwise,if θ_(-)=0,or,π,rotational symmetry is broken,leading to a nematic normal state.In both cases,the order parameters possess a 4-fermion structure beyond the scope of mean-field theory,which can be viewed as a high order symmetry breaking.We employ an effective two-component XY-model assisted by a renormalization group analysis to address this problem.As a natural by-product,we also find the other interesting intermediate phase corresponds to ordering of θ_+ but with θ_(-)disordered.This is the quartetting,or,charge-4e,superconductivity,which occurs above the low temperature Z_(2)-breaking charge-2e superconducting phase.Our results provide useful guidance for studying novel symmetry breaking phases in strongly correlated superconductors.

关键词： superconductivity strong correlation time-reversal breaking charge-4e

Gas microchannel plate-pixel detector for X-ray polarimetry

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第5期35卷 60-73页

作者： Huan-Bo Feng Hong-Bang Liu Dong Wang Zi-Li Li Shu-Lin Liu Qian Liu Hang-Zhou Li Bin-Long Wang Yan-Jun Xie Zong-Wang Fan Hui Wang Ran Chen Di-Fan Yi Rui-Ting Ma Fei Xie Bo Peng Xiang-Ming Sun Jin Li En-Wei Liang present address:Guangxi Key Laboratory for Relativistic Astrophysics School of Physical Science and TechnologyGuangxi UniversityNanning 530004China PLAC Key Laboratory of Quark and Lepton Physics(MOE)Central China Normal UniversityWuhan 430079China School of Science Huzhou UniversityHuzhou 313000China institute of High Energy physics Chinese Academy of SciencesBeijing 100049China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China School of Physical Science University of Chinese Academy of SciencesBeijing 100049China The 13th Research institute of China Electronics Technology Group Corporation Shijiazhuang 050057China

POLAR-2 is a gamma-ray burst(GRB)polarimeter that is designed to study the polarization in GRB radiation emissions,aiming to improve our knowledge of related mechanisms.POLAR-2 is expected to utilize an on-board polarimeter that is sensitive to soft X-rays(2-10 keV),called low-energy polarization detector.We have developed a new soft X-ray polari-zation detector prototype based on gas microchannel plates(GMCPs)and pixel chips(Topmetal).The GMCPs have bulk resistance,which prevents charging-up effects and ensures gain stability during operation.The detector is composed of low outgassing materials and is gas-sealed using a laser welding technique,ensuring long-term stability.A modulation factor of 41.28%±0.64% is obtained for a 4.5 keV polarized X-ray beam.A residual modulation of 1.96%±0.58% at 5.9 keV is observed for the entire sensitive area.

关键词： X-ray polarimetry Gas microchannel plate-pixel detector Gamma-ray bursts