Science China Physics, Mechanics & Astronomy最新文献

{"title":"The DESI DR1/DR2 evidence for dynamical dark energy is biased by low-redshift supernovae","authors":"Lu Huang,&nbsp;Rong-Gen Cai,&nbsp;Shao-Jiang Wang","doi":"10.1007/s11433-025-2754-5","DOIUrl":"10.1007/s11433-025-2754-5","url":null,"abstract":"<div><p>Recently, a 3<i>σ</i>-4<i>σ</i> preference for dynamical dark energy has been reported by the Dark Energy Spectroscopic Instrument (DESI) collaboration, which has inspired hot debates on new physics or systematics. In this paper, we reveal that this preference is significantly biased by an external low-redshift supernova (low-<i>z</i> SN) sample, which was combined with the Dark Energy Survey SN program (DES-SN) in their Year-Five data release (DESY5). Using the intercept in the SN magnitude-distance relation as a diagnostic for systematics, we find not only large dispersions but also a large discrepancy in the low-<i>z</i> SN sample when compared with the high-<i>z</i> DES-SN sample within the single DESY5 compilation, in contrast to the uniform behavior found in the PantheonPlus data. Correcting for this low-<i>z</i> systematics with or without including the cosmic microwave background data can largely reduce the preference for dynamical DE to be less than 2<i>σ</i>. Therefore, the DESI preference for dynamical DE is biased by some unknown systematics in the low-<i>z</i> SN sample.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"68 10","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144843194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Selection algorithm for observation points in environmental data assimilation based on the quantum squeezing effect","authors":"Hanyu Yang,&nbsp;Runqing Zhang,&nbsp;Zhihong Zhang,&nbsp;Nengfei Gong,&nbsp;Yancheng Jiang,&nbsp;Yuxuan Jia,&nbsp;Tiejun Wang","doi":"10.1007/s11433-025-2703-7","DOIUrl":"10.1007/s11433-025-2703-7","url":null,"abstract":"<div><p>In this paper, a quantum-enhanced framework is proposed to optimize observation point selection in environmental data assimilation. The method transforms the task into a QUBO problem, balancing uncertainty reduction and spatial diversity. By leveraging a quantum-inspired optical Ising machine, it avoids the exponential complexity of classical optimization. Tests on the Lorenz-1996 model demonstrate its superiority over traditional methods, enhancing computational efficiency without loss of accuracy. The findings underscore the potential of quantum-inspired optimization for scalable, real-time assimilation in high-resolution weather prediction, reducing dimensionality and computational cost.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"68 10","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144832132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dissipation suppression for an Unruh-DeWitt battery with a reflecting boundary","authors":"Xiaobao Liu,&nbsp;Zehua Tian,&nbsp;Jiliang Jing","doi":"10.1007/s11433-025-2723-7","DOIUrl":"10.1007/s11433-025-2723-7","url":null,"abstract":"<div><p>In the framework of open quantum systems, we study the dynamics of an accelerated quantum battery (QB), modeled as an Unruh-DeWitt detector interacting with a real massless scalar quantum field. The QB is driven by an external classical force acting as a charger. A major challenge in this setup is the environment-induced decoherence, which leads to energy dissipation of the QB. Accelerated motion exacerbates this dissipation, manifesting effects analogous to those experienced by a static QB in a thermal bath in free space, consistent with the Unruh effect. To overcome these challenges, we introduce a reflecting boundary in a space, which modifies the vacuum fluctuations of the field and leads to a position-dependent suppression of dissipation for the Unruh-DeWitt QB. Our analysis reveals that as the QB approaches the boundary, the relevant dissipation is significantly reduced. In particular, when the QB is placed extremely close to the boundary, the dissipation is nearly eliminated, as if the QB were a closed system. Furthermore, we identify a characteristic length scale associated with the acceleration of QB. When the distance between the QB and the boundary is much smaller than this scale, the boundary effectively suppresses dissipation, and this suppression effect becomes identical for both an accelerated QB and a static QB in a thermal bath. Conversely, when the distance is beyond this scale, the suppression effect weakens and manifests a significant difference between these two cases. Our findings demonstrate the potential of boundary-induced modifications in vacuum fluctuations to effectively suppress dissipation, offering valuable insights for optimizing QB performance. This work paves the way for the development of high-efficiency quantum energy storage systems in the relativistic framework.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"68 10","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144843260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phosphating-enhanced Fe-based amorphous soft magnetic composites with ultra-low power loss for efficient electrical energy conversion","authors":"Yanzhou Fan,&nbsp;Zhijun Guo,&nbsp;Min Wang,&nbsp;Changlong Jin,&nbsp;Jifeng Zhou,&nbsp;Yaqiang Dong,&nbsp;Qikui Man,&nbsp;Baolong Shen","doi":"10.1007/s11433-025-2711-2","DOIUrl":"10.1007/s11433-025-2711-2","url":null,"abstract":"<div><p>Soft magnetic composites (SMCs) play an indispensable role in electromagnetic conversion, transmission, and storage. However, achieving high-frequency, low-loss soft magnetic materials compatible with third-generation wide bandgap semiconductor devices remains a significant challenge. In this study, we report a novel strategy to fabricate Fe-based amorphous SMCs through a precisely controlled phosphating process. As the phosphoric acid content increases, the thickness of the insulating layer increases, resulting in higher resistivity. At the same time, the contribution of spin rotation to magnetization increases gradually and dominates throughout the magnetization. Compared with the untreated SMCs, the core loss (<i>P</i>_cv) of the SMCs treated with 1.0 wt.% phosphoric acid at 0.1 T/1 MHz was reduced by 11.6%, primarily due to the reduction of excess losses resulting from the different magnetization mechanisms. The optimized SMCs demonstrate outstanding overall magnetic performance, including ultra-low <i>P</i>_cv of 14.35 W/cm³ at 0.1 T/1 MHz, excellent DC-bias stability (69.4% at 100 Oe), relatively high saturation magnetic flux density (<i>B</i>_s = 0.84 T), and ultra-stable permeability (<i>μ</i>_e = 32.7) up to 20 MHz. These findings offer a promising pathway for designing high-performance SMCs tailored for high-frequency and high-power electronic applications.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"68 10","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144843258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal fractal characteristics of activation events during relaxation in disordered materials","authors":"Senkuan Meng,&nbsp;Yijun Ding,&nbsp;Wei Chu,&nbsp;Feilong Shi,&nbsp;Ruiqi Yu,&nbsp;Lina Hu,&nbsp;Zheng Wang","doi":"10.1007/s11433-025-2706-4","DOIUrl":"10.1007/s11433-025-2706-4","url":null,"abstract":"<div><p>The investigation of physical processes across various temporal scales is essential for comprehending and forecasting the behavior of intricate systems over extended periods. Relaxation processes, which span 16 orders of magnitude, are a prime example of multiscale physical processes. However, the description of the relaxation process across multiple time spans is not yet clear. This study employs advanced flash differential scanning calorimetry to probe multiscale relaxation dynamics across various glass systems. We discovered that the relaxation behavior exhibits self-similar scaling across multiple time scales, arising from the accumulation of temporally fractal activation events. Due to the heterogeneous distribution of energy in the system, not every activation event contributes to global energy reduction. Microscopic mechanisms underlying the temporal fractal of activation events are proposed based on both experimental and simulation results. The temporal fractal serves as a critical link connecting microscopic activation events with macroscopic relaxation processes in disordered materials. This fractal framework provides a powerful approach for probing multiscale dynamics in complex systems.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"68 10","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144843259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Continuous variable quantum communication with 40 pairs of entangled sideband modes","authors":"Xuan Liu,&nbsp;Shaoping Shi,&nbsp;Yimiao Wu,&nbsp;Xuan Wang,&nbsp;Long Tian,&nbsp;Wei Li,&nbsp;Yajun Wang,&nbsp;Yaohui Zheng","doi":"10.1007/s11433-025-2746-x","DOIUrl":"10.1007/s11433-025-2746-x","url":null,"abstract":"<div><p>Constructing large-scale quantum resources is an important foundation for further improving the efficiency and scalability of quantum communication. Here, we present an efficient extraction and stable control scheme of 40 pairs of entangled sideband modes from the squeezed light by specially designing an optical parametric oscillator. Utilizing the low-loss optical frequency comb control technology and the local cross-correlation algorithm, we model and manage the efficient separation process of the entangled sideband modes facilitated by the optical filtering cavities, and a maximum entanglement level of 6.5 dB is achieved. The feasibility of large-capacity quantum dense coding based on these entangled sideband modes is proved experimentally, which is of great significance for optimizing the utilization of quantum resources, thereby contributing to the advancement of large- capacity quantum communication networks and enabling the realization of more secure and efficient quantum communication systems.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"68 12","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144832128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Jiutian simulations for the CSST extra-galactic surveys","authors":"Jiaxin Han,&nbsp;Ming Li,&nbsp;Wenkang Jiang,&nbsp;Zhao Chen,&nbsp;Huiyuan Wang,&nbsp;Chengliang Wei,&nbsp;Feihong He,&nbsp;Jianhua He,&nbsp;Jiajun Zhang,&nbsp;Yu Liu,&nbsp;Weiguang Cui,&nbsp;Yizhou Gu,&nbsp;Qi Guo,&nbsp;Yipeng Jing,&nbsp;Xi Kang,&nbsp;Guoliang Li,&nbsp;Xiong Luo,&nbsp;Yu Luo,&nbsp;Wenxiang Pei,&nbsp;Yisheng Qiu,&nbsp;Zhenlin Tan,&nbsp;Lizhi Xie,&nbsp;Xiaohu Yang,&nbsp;Haoran Yu,&nbsp;Yu Yu,&nbsp;Jiale Zhou","doi":"10.1007/s11433-025-2712-1","DOIUrl":"10.1007/s11433-025-2712-1","url":null,"abstract":"<div><p>We provide an overview of the Jiutian simulations, a hybrid simulation suite for the China space survey telescope (CSST) extra-galactic surveys. It consists of four complementary modules: the primary runs with high resolutions with the fiducial concordance cosmology, the emulator runs exploring the parameter uncertainties around the fiducial cosmology, the reconstruction runs intended for recovering the observed Universe position by position, and the extension runs employing extended cosmologies beyond the standard model. For the primary runs, two independent pipelines are adopted to construct subhaloes and merger trees. On top of them, four sets of mock galaxy light-cone catalogs are produced from semi-analytical models and subhalo abundance matching, providing a variety of observational properties including galaxy spectral energy distribution (SED), emission lines, lensing distortions, and mock images. The 129 emulator runs are used to train the CSST emulator, achieving one percent accuracy in predicting the matter power spectrum over <i>k</i> ⩽ 10 <i>h</i>Mpc⁻¹ and <i>z</i> ⩽ 2. The reconstruction runs employ a number of subgrid baryonic models to predict the evolution and galaxy population resembling certain regions in the real Universe with constrained initial conditions, enabling controlled investigation of galaxy formation on top of structure formation. The extension runs cover models with warm dark matter, <i>f</i>(<i>R</i>) gravity, interacting dark energy, and nonzero neutrino masses, revealing differences in the cosmic structure under alternative cosmological models. We introduce the specifications for each run, the data products derived from them, the corresponding pipeline developments, and present some main tests. Using the primary runs, we also show that the subhalo peak mass functions of different levels are approximately universal. These simulations form a comprehensive and open simulation library for CSST surveys and beyond.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"68 10","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145162753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Scaling law for three-body collisions near a narrow s-wave Feshbach resonance","authors":"Jiaming Li,&nbsp;Shuai Peng,&nbsp;Yirou Xu,&nbsp;Shiyin Kuang,&nbsp;Le Luo","doi":"10.1007/s11433-025-2734-6","DOIUrl":"10.1007/s11433-025-2734-6","url":null,"abstract":"<div><p>Ultracold atomic gases provide a controllable system to investigate the universal scaling laws of three-body physics, that is how the three-body recombination depends on the two-body scattering length. Although these scaling laws have been carefully examined in the bosonic systems, their manifestation in fermionic systems remain elusive. In this study, we investigate the three-body atomic loss rate <i>L</i>₃ in a two-component ⁶Li Fermi gas with a negative scattering length <i>a</i> &lt; 0. Our experimental results indicate that the scaling law exists near the narrow <i>s</i>-wave Feshbach resonance, characterized by <i>L</i>₃ ∝ ∣<i>a</i>∣^2.60. This scaling is observed to be valid only within a certain range of a, breaking down at both extremes. On one end, in the unitary regime where ∣<i>a</i>∣ approaches infinity, the collisional rate becomes independent of <i>a</i>. On the other end, as <i>a</i> approaches zero, a change in the length scale occurs, resulting in <i>L</i>₃ ∝ <i>r</i><span>\u0000 ^2.30_vdw\u0000 \u0000 </span>, where the van der Waals length <i>r</i>_vdw becomes the dominate scaling length. This study resolves the puzzle of the scaling law on the Bardeen-Cooper-Schrieffer (BCS) side of a two-component Fermi gas, shedding light on the universal physics in few-body systems.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"68 12","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145162322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new type of fine spectral structure in the solar radio emission","authors":"Alexey Kuznetsov","doi":"10.1007/s11433-025-2733-3","DOIUrl":"10.1007/s11433-025-2733-3","url":null,"abstract":"","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"68 10","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145161869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"(Toverline{T}) deformation: Introduction and some recent advances","authors":"Song He,&nbsp;Yi Li,&nbsp;Hao Ouyang,&nbsp;Yuan Sun","doi":"10.1007/s11433-025-2708-2","DOIUrl":"10.1007/s11433-025-2708-2","url":null,"abstract":"<div><p>This review explores recent advances in the theory of <span>(Toverline{T})</span> deformation, an irrelevant yet solvable deformation of quantum field theories defined via the quadratic form of the energy-momentum tensor. It addresses classical and quantum aspects, highlighting significant developments across various fields, including field theory, holography, and string theory. Classically, <span>(Toverline{T})</span> deformation manifests through multiple geometric interpretations, notably random geometry, Jackiw-Teitelboim-like gravity, and uniform light-cone gauge frameworks. For quantum aspects, the deformation introduces notable features such as non-locality, UV-IR mixing, solvable renormalization structures, and intriguing modifications to correlation functions and entanglement properties. Furthermore, the paper examines the profound relationship between <span>(Toverline{T})</span> deformation and holography, particularly within the mixed boundary conditions/cutoff AdS holography proposal and holographic entanglement entropy. Connections to string theory through single-trace deformations and their holographic duals further reveal the deformed structure of the worldsheet. This review synthesizes recent developments and outlines potential directions for future research in the study of <span>(Toverline{T})</span>-like deformation.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"68 10","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145161868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}