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中国科学:物理学 力学 天文学（英文版）
中国科学:物理学 力学 天文学（英文版）

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中国科学:物理学 力学 天文学（英文版）/Journal Science China(Physics, Mechanics&Astronomy)CSCDCSTPCDEISCI
查看更多>>《中国科学》是中国科学院主办、中国科学杂志社出版的自然科学专业性学术刊物。《中国科学》任务是反映中国自然科学各学科中的最新科研成果，以促进国内外的学术交流。《中国科学》以论文形式报道中国基础研究和应用研究方面具有创造性的、高水平的和有重要意义的科研成果。在国际学术界，《中国科学》作为代表中国最高水平的学术刊物也受到高度重视。国际上最具有权威的检索刊物SCI，多年来一直收录《中国科学》的论文。1999年《中国科学》夺得国家期刊奖的第一名。
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    Suppressing noisy features with quantum filters for efficient encoded images with high signal to noise ratios

    Gui-Lu Long
    1页
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    Quantum advantages for image filtering on images with efficient encoding and lower-bounded signal-to-noise ratio

    Zidong CuiShan JinAkira SoneXiaoting Wang...
    2-12页
    查看更多>>摘要：Quantum image processing has long been a fascinating field,but establishing the existence of quantum speedup for all images remains challenging.In this study,we aim to identify a subset of images for which a quantum algorithm can be developed with a guaranteed advantage.Specifically,we present a quantum image filtering algorithm that exhibits an exponential speedup for efficiently encoded images with a lower-bounded signal-to-noise ratio.Our approach relies on a fixed-point Grover's search to emulate the effect of Hadamard multiplication with the filtering function.To demonstrate its effectiveness,we apply our method to three typical filtering problems.Additionally,we emphasize the significance of the efficient-encoding assumption by illus-trating that the quantum speedup may diminish for images lacking efficient encoding.Our work underscores the importance of exploring image types and features to realize potential quantum advantages in image processing.
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    Advancements in quantum image filtering:Exponential speedup on a subset of images

    Lvzhou Li
    13页
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    Advances in laser-plasma interactions using intense vortex laser beams

    Yin ShiXiaomei ZhangAlexey ArefievBaifei Shen...
    14-42页
    查看更多>>摘要：Low-intensity light beams carrying orbital angular momentum(OAM),commonly known as vortex beams,have garnered sig-nificant attention due to promising applications in areas ranging from optical trapping to communication.In recent years,there has been a surge in global research exploring the potential of high-intensity vortex laser beams and specifically their interac-tions with plasmas.This paper provides a comprehensive review of recent advances in this area.Compared with conventional laser beams,intense vortex beams exhibit unique properties such as twisted phase fronts,OAM delivery,hollow intensity dis-tribution,and spatially isolated longitudinal fields.These distinct characteristics give rise to a multitude of rich phenomena,profoundly influencing laser-plasma interactions and offering diverse applications.The paper also discusses future prospects and identifies promising general research areas involving vortex beams.These areas include low-divergence particle acceleration,instability suppression,high-energy photon delivery with OAM,and the generation of strong magnetic fields.With growing scientific interest and application potential,the study of intense vortex lasers is poised for rapid development in the coming years.
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    Signifying quantum uncertainty relations by optimal observable sets and the tightest uncertainty constants

    Xiao-Bin LiangBo LiShao-Ming Fei
    43-50页
    查看更多>>摘要：Quantum uncertainty relations constrain the precision of measurements across multiple non-commuting quantum mechanical ob-servables.Here,we introduce the concept of optimal observable sets and define the tightest uncertainty constants to accurately describe these measurement uncertainties.For any quantum state,we establish optimal sets of three observables for both prod-uct and summation forms of uncertainty relations,and analytically derive the corresponding tightest uncertainty constants.We demonstrate that the optimality of these sets remains consistent regardless of the uncertainty relation form.Furthermore,the existence of the tightest constants excludes the validity of standard real quantum mechanics,underscoring the essential role of complex numbers in this field.Additionally,our findings resolve the conjecture posed in[Phys.Rev.Lett.118,180402(2017)],offering novel insights and potential applications in understanding preparation uncertainties.
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    Quantum control for time-dependent noise by inverse geometric optimization

    Xiaodong YangYingcheng LiRan LiuXinfang Nie...
    51-57页
    查看更多>>摘要：Quantum systems are exceedingly difficult to engineer because they are sensitive to various types of noises.In particular,time-dependent noises are frequently encountered in experiments but how to overcome them remains a challenging problem.In this work,we propose a flexible robust control technique to resist time-dependent noises based on inverse geometric optimization working in the filter-function formalism.The basic idea is to parameterize the control filter function geometrically and minimize its overlap with the noise spectral density.This then effectively reduces the noise susceptibility of the controlled system evolu-tion.We show that the proposed method can produce high-quality robust pulses for realizing desired quantum evolutions under realistic noise models.Also,we demonstrate this method in examples including dynamical decoupling and quantum sensing protocols to enhance their performances.
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    Primordial black holes and curvature perturbations from false vacuum islands

    Rong-Gen CaiYu-Shi HaoShao-Jiang Wang
    58-72页
    查看更多>>摘要：Recently,much attention has been focused on the false vacuum islands that are flooded by an expanding ocean of true-vacuum bubbles slightly later than most of the other parts of the world.These delayed decay regions will accumulate locally larger vacuum energy density by staying in the false vacuum longer than those already transited into the true vacuum.A false vacuum island with thus acquired density contrast of a super-horizon size will evolve locally from radiation dominance to vacuum dom-inance,creating a local baby Universe that can be regarded effectively as a local closed Universe.If such density contrasts of super-horizon sizes can ever grow large enough to exceed the threshold of gravitational collapse,primordial black holes will form similar to those collapsing curvature perturbations on super-horizon scales induced by small-scale enhancements during inflation.If not,such density contrasts can still induce curvature perturbations potentially observable today.In this paper,we revisit and elaborate on the generations of primordial black holes and curvature perturbations from delayed-decayed false vacuum islands during asynchronous first-order phase transitions with fitting formulas convenient for future model-independent studies.
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    Energy flux and waveform of gravitational wave generated by coalescing slow-spinning binary system in effective one-body theory

    Weike DengSheng LongJiliang Jing
    73-83页
    查看更多>>摘要：We extend our research on the energy flux and waveform characteristics of gravitational waves generated by merging nonspinning binary black holes through self-consistent effective one-body theory to include binary systems with slowly spinning black holes.Initially,we decompose the equation for the null tetrad component of the gravitationally perturbed Weyl tensor ψB4 into radial and angular parts,leveraging the second-order approximation of the rotation parameter a.Subsequently,we derive an analytical solution for the radial equation and observe that our results are contingent upon the parameters a2,a3,and a,which represent the second-and third-order correction parameters,respectively.Ultimately,we calculate the energy flux,the radiation-reaction force and the waveform for the"plus"and"cross"modes of the gravitational waves generated by merging slowly spinning binary black holes.
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    Precise determination of the pole position of the exotic Zc(3900)

    Yun-Hua ChenMeng-Lin DuFeng-Kun Guo
    84-90页
    查看更多>>摘要：We perform a unified description of the experimental data of the π+π-and J/ψπ±invariant mass spectra for e+e-→ J/ψπ+π-and the D0D*-mass spectrum for e+e-→D0D*-+at e+e-center-of-mass energies 4.23 and 4.26 GeV.The analysis takes into account open-charm meson loops that contain triangle singularities,the J/ψπ-D(D)* coupled-channel interaction respecting unitarity,and the strong ππ-K(K)final state interaction using dispersion relations.The analysis leads to a precise determination of the Zc(3900)pole with the pole mass and width(3880.7±1.7stat±22.4syst)MeV and(35.9±1.4stat±15.3syst)MeV,respectively,and hints at that the DD*molecular and non-molecular components are of similar importance in the Zc(3900)formation.
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    Harpoon-shaped topological photonic crystal for on-chip beam splitter

    Zhiwei GuanRuixue DouChuangxin XieTianyimei Zuo...
    91-98页
    查看更多>>摘要：The advancement of integrated optical communication networks necessitates the deployment of on-chip beam splitters for efficient signal interconnections at network nodes.However,the pursuit of micron-scale beam splitting with large comers and reducing the device footprint to boost connection flexibility often results in phase mismatches.These mismatches,which stem from radiation modes and backward scattering,pose significant obstacles in creating highly integrated and interference-resistant connections.To address this,we introduce a solution based on the topological valley-contrasting state generated by photonic crystals with opposing valley Chem numbers,manifested in a harpoon-shaped structure designed to steer the splitting channels.This approach enables adiabatic mode field evolution over large comers,capitalizing on the robust phase modulation capabilities and topological protection provided by the subwavelength-scale valley-contrasting state.Our demonstration reveals that beam splitters with large corners of 60°,90°,and 120° exhibit insertion loss fluctuations below 2.7 dB while maintaining a minimal footprint of 8.8 μm × 8.8 μm.As a practical demonstration,these devices facilitate three-channel signal connections,success-fully transmitting quadrature phase shift keying signals at 3.66 Tbit/s with bit error rates below the forward error correction threshold,demonstrating performance comparable to that in defects scenarios.By harnessing the unidirectional excitation feature,we anticipate significant enhancements in the capabilities of signal distribution and connection networks through a daisy chain configuration.
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