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Entropy of deterministic trajectory via trajectories ensemble

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Chinese physics B 2024年第6期33卷 347-354页

作者：彭勇刚冉翠平郑雨军 school of physics Shandong UniversityJinan 250100China

We present a formulation of the single-trajectory entropy using the trajectories ensemble. The single-trajectory entropy is affected by its surrounding trajectories via the distribution function. The single-trajectory entropies are studied in two typical potentials, i.e., harmonic potential and double-well potential, and in viscous environment by interacting trajectory method. The results of the trajectory methods are in agreement well with the numerical methods(Monte Carlo simulation and difference equation). The single-trajectory entropies increasing(decreasing) could be caused by absorption(emission) heat from(to) the thermal environment. Also, some interesting trajectories, which correspond to the rare evens in the processes, are demonstrated.

关键词： trajectory entropy trajectories ensemble

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

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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

Scaling laws governing the elastic properties of 3D graphenes

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Science China Technological Sciences 2024年第6期67卷 1748-1756页

作者： LI Ming LU Guo YU HaoDong LI MengLei ZHENG FaWei Centre for Quantum physics Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement(MOE)School of PhysicsBeijing Institute of Technology Beijing Key Lab of Nanophotonics & Ultrafine Optoelectronic Systems School of PhysicsBeijing Institute of Technology Laboratory of Computational physics Institute of Applied Physics and Computational Mathematics Department of physics Capital Normal University

In this study, we comprehensively investigated the scaling law for elastic properties of three-dimensional honeycomb-like graphenes（3D graphenes） using hybrid neural network potential-based molecular dynamics simulations and theoretical analyses. The elastic constants were obtained as functions of honeycomb hole size, denoted by the graphene wall length L. All five independent elastic constants in the large-L limit are proportional to L-1. The associated coefficients are combinations of elastic constants of two-dimensional graphene. High-order terms including L-2and L-3emerge for finite L values. They have three origins, the distorted areas close to the joint lines of 3D graphenes, the variation in solid angles between graphene plates, and the bending distortion of graphene plates. Significantly, the chirality becomes essential with decreasing L because the joint line structures are different between the armchair and zigzag-type 3D graphenes. Our findings provide insights into the elastic properties of graphene-based superstructures and can be used for further studies on graphene-based materials.

关键词： scaling law neural network elastic properties 3D graphene

Progenitor-age dependence of type Ia supernova luminosity and its cosmological implication

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Science China(physics,Mechanics & astronomy) 2024年第1期67卷 180-181页

作者： Yanhong Yao Yang Wang Haitao Miao school of physics and astronomy Sun Yat-sen UniversityZhuhai 519082China Peng Cheng Laboratory Shenzhen 518000China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China

Empirically standardised peak luminosity of Type Ia supernovae(SNe Ia)as a standard candle has become one of the most powerful probes of the expansion history of the late universe.Although the existence of such a consistent peak luminosity could be interpreted as a consequence of the fixed critical Chandrasekhar mass at which a carbon-oxygen white dwarf explodes,there is growing evidence for a more complex environmental dependence to the SN Ia luminosity beyond the current understanding of the SN Ia physics.

关键词： luminosity supernova consequence

An improved bound on accelerated light dark matter

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Science China(physics,Mechanics & astronomy) 2024年第2期67卷 105-118页

作者： Liangliang Su Lei Wu Bin Zhu Department of physics and Institute of Theoretical physics Nanjing Normal UniversityNanjing 210023China school of physics Yantai UniversityYantai 264005China

Light(sub-GeV)dark matter has gained increasing interest in terms of direct detection.Accelerated dark matter is a promising candidate that can generate detectable nuclear recoil energy within the sub-GeV range.Because of the large kinetic energy,its interactions with the nucleus are predominantly governed by inelastic scattering,including quasi-elastic and deep inelastic scattering.In this work,we calculated the inelastic effects in dark matter-Earth scattering mediated by a vector particle.Our analysis revealed that the impact of inelastic scattering relies on the mediator mass and the kinetic energy spectrum of dark matter.The results exhibited considerable disparity:the upper bounds of the exclusion limit for the spin-independent cross-section between accelerated dark matter and nuclei via a heavy mediator differ by several tens of times when inelastic scattering is considered.

关键词： accelerated dark matter inelastic scattering direct detection experiment

Tuning structural,electrical,dielectric and magnetic properties of Mg-Cu-Co ferrites via dysprosium(Dy^(3+))doping

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Journal of Rare Earths 2024年第1期42卷 137-146,I0005页

作者： Maria Akhtar M.S.Hasan Nasir Amin N.A.Morley Muhammad Imran Arshad Department of physics Government College UniversityFaisalabad38000Pakistan Department of physics The University of Lahore53700Pakistan Department of Materials Science and Engineering The University of SheffieldS13JDUK Department of physics&astronomy University College LondonUK

In current research work,Dy3+substituted Mg0.5Cu0.25Co0.25Fe2-xDyxO4(0.0≤x≤0.04 with the step interval of 0.01)soft ferrites were synthesized by the sol-gel auto combustion method.The prepared samples were characterized by the techniques using X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive X-ray spectroscopy(EDS),Fourier transform infrared(FTIR)spectroscopy,curre nt-voltage(Ⅰ-Ⅴ)measurement,LCR meter,vibrating sample magnetometer(VSM)and Raman.XRD data reveal that the average crystallite size is 49.71 nm and the lattice constant is 0.83703 nm for sample x=0.03.The non-uniform grain growth was demonstrated by micrographs and impurity-free elemental composition was observed from EDX analysis.The DC resistivity has an increasing and decreasing trend in ferromagnetic and paramagnetic regions with an increase in temperature.Moreover,the high resistivity is observed with the order of 1010Ω·cm,and the activation energy is 0.944 eV for samples x=0.03.The dielectric parameters including dielectric constant,dielectric losses,and impedance gradually decrease with the increase in frequency from 8 Hz to 8 MHz.The minimum dielectric loss at high frequency is found for sample x=0.03.The coercivity(Hc)and saturation magnetization(Ms)are found in the ranges of 520.82-544.02 Oe and 20.5841-21.1473 emu/g,respectively.These observations confirm that dysprosium(x=0.03)doped MCC-soft ferrites may be applicable in transformer cores,microwave absorbance,and telecommunication devices.

关键词： Soft ferrites DC resistivity Dielectric loss Impedance Coercivity Rare earths

Morphology Study for GeV Emission of Nearby Supernova Remnant G332.5-5.6

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Research in astronomy and Astrophysics 2024年第4期24卷 134-140页

作者： Ming-Hong Luo Qing-Wen Tang Xiu-Rong Mo Department of physics School of Physics and Materials ScienceNanchang UniversityNanchang 330031China

A spatial template is important to study nearby supernova remnants(SNRs).For SNR G332.5-5.6,we report a Gaussian disk with a radius of about 1°.06 to be a potential good spatial model in the γ-ray band.Employing this new Gaussian disk,its GeV lightcurve shows a significant variability of about seven sigma.The γ-ray observations of this SNR could be explained well either by a leptonic model or a hadronic model,in which a flat spectrum for the ejected electrons/protons is required.

关键词： ISM:supernova remnants gamma rays:ISM

Development of a monochromatic crystal backlight imager for the recent double-cone ignition experiments

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Chinese physics B 2024年第2期33卷 40-45页

作者：张成龙张翌航远晓辉张喆徐妙华戴羽董玉峰谷昊琛刘正东赵旭李玉同李英骏朱健强张杰 State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyBeijing 100083China Beijing National Laboratory for Condensed Matter physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China Key Laboratory for Laser Plasmas(MoE)and school of physics and astronomy Shanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center of IFSA(CICIFSA) Shanghai Jiao Tong UniversityShanghai 200240China Songshan Lake Materials Laboratory Dongguan 523808China school of Science China University of Mining and Technology(Beijing)Beijing 100089China school of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Department of astronomy Beijing Normal UniversityBeijing 100875China Institute for Frontiers in astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China Key Laboratory of High Power Laser and physics Chinese Academy of SciencesShanghai 201800China

We developed a monochromatic crystal backlight imaging system for the double-cone ignition(DCI) scheme, employing a spherically bent quartz crystal. This system was used to measure the spatial distribution and temporal evolution of the head-on colliding plasma from the two compressing cones in the DCI experiments. The influence of laser parameters on the x-ray backlighter intensity and spatial resolution of the imaging system was investigated. The imaging system had a spatial resolution of 10 μm when employing a CCD detector. Experiments demonstrated that the system can obtain time-resolved radiographic images with high quality, enabling the precise measurement of the shape, size, and density distribution of the plasma.

关键词： double-cone ignition(DCI) spatial resolution x-ray radiography

Dynamical control of nanoscale light-matter interactions in low-dimensional quantum materials

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Light(Science & Applications) 2024年第2期13卷 236-253页

作者： Yeonjeong Koo Taeyoung Moon Mingu Kang Huitae Joo Changjoo Lee Hyeongwoo Lee Vasily Kravtsov Kyoung-Duck Park Department of physics Pohang University of Science and Technology(POSTECH)Pohang37673Republic of Korea school of physics and Engineering ITMO UniversitySaint Petersburg197101Russia

Tip-enhanced nano-spectroscopy and-imaging have significantly advanced our understanding of low-dimensional quantum materials and their interactions with light,providing a rich insight into the underlying physics at their natural length scale.Recently,various functionalities of the plasmonic tip expand the capabilities of the nanoscopy,enabling dynamic manipulation of light-matter interactions at the nanoscale.In this review,we focus on a new paradigm of the nanoscopy,shifting from the conventional role of imaging and spectroscopy to the dynamical control approach of the tip-induced light-matter interactions.We present three different approaches of tip-induced control of light-matter interactions,such as cavity-gap control,pressure control,and near-field polarization control.Specifically,we discuss the nanoscale modifications of radiative emissions for various emitters from weak to strong coupling regime,achieved by the precise engineering of the cavity-gap.Furthermore,we introduce recent works on light-matter interactions controlled by tip-pressure and near-field polarization,especially tunability of the bandgap,crystal structure,photoluminescence quantum yield,exciton density,and energy transfer in a wide range of quantum materials.We envision that this comprehensive review not only contributes to a deeper understanding of the physics of nanoscale light-matter interactions but also offers a valuable resource to nanophotonics,plasmonics,and materials science for future technological advancements.

关键词： quantum precise shifting