Science China Physics, Mechanics & Astronomy最新文献

{"title":"Spin polarization and quantum entanglement of baryon-antibaryon pairs produced in electron-positron annihilation","authors":"Cheng Chen,&nbsp;Ju-Jun Xie","doi":"10.1007/s11433-026-3063-4","DOIUrl":"10.1007/s11433-026-3063-4","url":null,"abstract":"<div><p>In this work, we systematically investigate the evolution of spin polarization and quantum entanglement in cascade decays of baryon-antibaryon pairs, which are produced in electron-positron annihilation. We derive a fully analytical spin density matrix explicitly expressed in terms of spin polarization observables, extend this formalism to multi-step cascade decay scenarios, and establish compact recursive relations to facilitate density matrix calculations for such processes. It is found that when maximal parity violation occurs during a decay, the resulting final-state particles are fully polarized and disentangled. Furthermore, we demonstrate that quantum entanglement amplification is a generic characteristic of charge-conjugate decays under <i>CP</i> conservation when the initially produced baryon-antibaryon pair is polarized.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"69 11","pages":""},"PeriodicalIF":7.2,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149132814","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":"Learning parton fragmentation with QCD built in","authors":"Kai Zhou","doi":"10.1007/s11433-026-3094-3","DOIUrl":"10.1007/s11433-026-3094-3","url":null,"abstract":"","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"69 11","pages":""},"PeriodicalIF":7.2,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149132815","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":"Thermodynamic scaling laws and ionization kinetics of laser-produced tin plasmas at various pressures and irradiating laser energies","authors":"Zihao Song,&nbsp;Qi Xu,&nbsp;Chao Sun,&nbsp;Xing Chao","doi":"10.1007/s11433-026-3073-9","DOIUrl":"10.1007/s11433-026-3073-9","url":null,"abstract":"<div><p>Laser-produced tin plasmas are fundamental to extreme ultraviolet (EUV) lithography, yet optimizing their emission efficiency requires precise empirical boundary conditions for high-fidelity radiation-hydrodynamics simulations. In this study, the ionization kinetics and thermodynamic scaling laws of solid-Sn laser-produced plasmas were systematically investigated using quantitative optical emission spectroscopy (OES), by extracting the electron temperature (<i>T</i>_e) and electron density (<i>N</i>_e) under varying incident laser energies and ambient pressures. Results reveal that in a controlled low-pressure environment of 50 mbar, the plasma efficiently couples with the laser, exhibiting a robust power-law scaling of <i>T</i>_e ∝ <i>E</i>^0.43, close to the theoretical 4/9 limit of the classical self-regulating regime. In contrast, atmospheric confinement severely suppresses this scaling to <i>E</i>^0.27 due to prominent plasma shielding and plasma-gas interactions. Furthermore, the electron density evolution demonstrates a distinct two-stage ionization mechanism, transitioning to dominant electron avalanche ionization above a 110 mJ threshold. Statistical analysis confirms that low-pressure conditions effectively suppress macroscopic hydrodynamic instabilities, minimizing single-shot <i>T</i>_e fluctuations to below 0.05 eV. These results establish a reproducible spectroscopic dataset and quantitative scaling framework for benchmarking radiation-hydrodynamics models of solid-Sn laser-produced plasmas relevant to EUV source development.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"69 11","pages":""},"PeriodicalIF":7.2,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149132816","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":"MUltiplexed Survey Telescope (MUST) science white paper I: Overview of large-scale structure cosmology in the era of Stage-V spectroscopic surveys","authors":"Cheng Zhao,&nbsp;Song Huang,&nbsp;Mengfan He,&nbsp;Paulo Montero-Camacho,&nbsp;Yu Liu,&nbsp;Pablo Renard,&nbsp;Yunyi Tang,&nbsp;Aurélien Verdier,&nbsp;Wenshuo Xu,&nbsp;Xiaorui Yang,&nbsp;Jiaxi Yu,&nbsp;Yao Zhang,&nbsp;Siyi Zhao,&nbsp;Xingchen Zhou,&nbsp;Sheng-Yu He,&nbsp;Jean-Paul Kneib,&nbsp;Jiayi Li,&nbsp;Zhuoyang Li,&nbsp;Wen-Ting Wang,&nbsp;Zhong-Zhi Xianyu,&nbsp;Yidian Zhang,&nbsp;Rafaela Gsponer,&nbsp;Xiao-Dong Li,&nbsp;Antoine Rocher,&nbsp;Siwei Zou,&nbsp;Ting Tan,&nbsp;Zhiqi Huang,&nbsp;Zhuoxiao Wang,&nbsp;Pei Li,&nbsp;Maxime Rombach,&nbsp;Chenxing Dong,&nbsp;Daniel Forero-Sánchez,&nbsp;Yuanhang Ning,&nbsp;Huanyuan Shan,&nbsp;Tao Wang,&nbsp;Yin Li,&nbsp;Zhongxu Zhai,&nbsp;Yuting Wang,&nbsp;Gong-Bo Zhao,&nbsp;Yong Shi,&nbsp;Shude Mao,&nbsp;Lei Huang,&nbsp;Liquan Guo,&nbsp;Zheng Cai","doi":"10.1007/s11433-026-2998-9","DOIUrl":"10.1007/s11433-026-2998-9","url":null,"abstract":"<div><p>The MUltiplexed Survey Telescope (MUST) is a 6.5-m telescope under development. Dedicated to highly-multiplexed, wide-field spectroscopic surveys, MUST observes over 20000 targets simultaneously using 6.2-mm pitch positioning robots within a ∼5 deg² field of view. MUST aims to conduct the first Stage-V spectroscopic survey in the 2030s, mapping the 3D Universe with over 100 million galaxies and quasars, spanning from the nearby Universe to a redshift of <i>z</i> ∼ 5.5, corresponding to approximately 1 billion years after the Big Bang. To cover this extensive redshift range, we present an initial conceptual target-selection algorithm for different types of galaxies, including local bright galaxies, luminous red galaxies, emission-line galaxies, and high-redshift (2 &lt; <i>z</i> &lt; 5.5) Lyman-break galaxies. Using Fisher forecasts, we demonstrate that MUST can address fundamental questions in cosmology, including the nature of dark energy, tests of gravity theories, and investigations into primordial physics. This is the first paper in a series of science white papers for MUST, with subsequent papers focusing on additional scientific cases, including galaxy and quasar evolution, Milky Way physics, and dynamic phenomena in the time-domain Universe.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"69 11","pages":""},"PeriodicalIF":7.2,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11433-026-2998-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149132813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Constraints on axion-like particles with the silicon detector at a nuclear reactor","authors":"Yuanlin Gong,&nbsp;Jun Guo,&nbsp;Ning Liu,&nbsp;Liangliang Su,&nbsp;Wen-Na Yang","doi":"10.1007/s11433-026-3066-5","DOIUrl":"10.1007/s11433-026-3066-5","url":null,"abstract":"<div><p>Axion and axion-like particles (ALPs), predicted in various extensions of the Standard Model, can be abundantly produced in nuclear reactors via the Primakoff process. In this work, we explore the detection of ALPs in silicon detectors through plas-mon excitations. Owing to their relativistic nature, reactor-produced ALPs can efficiently excite plasmon resonances, while the accompanying energetic photon typically escapes from the thin detector without depositing an appreciable amount of energy. Utilizing the data from the Connie and Atucha-II experiments, we set the 90% confidence level upper limits on the ALP-photon coupling <i>g</i>_<i>aγγ</i> over the axion mass range 0.1–100 keV. We further show that, for an exposure of 30 kg yr, the projected sensitivity of vIOLETA exceeds the current NEON limit by a factor of three in the same mass range. This improvement would expand the explored region of the QCD axion and ALP parameter space.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"69 11","pages":""},"PeriodicalIF":7.2,"publicationDate":"2026-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149132806","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":"Discovery of massive three-dimensional periodic orbits for the general three-body problem","authors":"Xiaoming Li,&nbsp;Shijun Liao","doi":"10.1007/s11433-026-3056-8","DOIUrl":"10.1007/s11433-026-3056-8","url":null,"abstract":"<div><p>Periodic orbits form the organizing skeleton of phase space in the three-body problem. While planar periodic solutions have been extensively studied, three-dimensional configurations remain comparatively scarce due to their increased complexity. Here we report the discovery of 10,059 three-dimensional periodic orbits of the three-body problem with two or three equal masses. The solutions span a diverse array of families, including spatial Lagrange, Sitnikov-like, Broucke-Hadjidemetriou-Hénon (BHH), and figure-8, as well as many sequences with more intricate topologies. Notably, approximately 20% (1,996) of these orbits are linearly stable, suggesting that they could arise in dense stellar systems. We further highlight two novel classes: 21 choreographic orbits for the three-equal-mass case, where all three bodies share a single closed 3D trajectory; and 273 “piano-trio” orbits, where the two equal masses share one closed loop while the third body follows a distinct path. We also demonstrate that these periodic orbits can be numerically continued to systems in which all three masses are distinct. These results provide a broad 3D atlas of periodic solutions and advance the global characterization of three-body dynamics.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"69 11","pages":""},"PeriodicalIF":7.2,"publicationDate":"2026-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11433-026-3056-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149132807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient terahertz emission from a single-layer ferromagnet via co-existing spin and charge conversion","authors":"Cheng Li,&nbsp;Xiaotong Han,&nbsp;Rongxin Li,&nbsp;Hongsong Qiu,&nbsp;Bo Wei,&nbsp;Ye Zhang","doi":"10.1007/s11433-026-3064-8","DOIUrl":"10.1007/s11433-026-3064-8","url":null,"abstract":"<div><p>Optically pumped spintronic terahertz (THz) emitters based on ferromagnetic/nonmagnetic (FM/NM) heterostructures present a promising scheme for broadband, low-cost THz generation. However, their efficiency is fundamentally limited by interfacial spin transmission losses, and their dependence on external magnetic fields complicates device integration and miniaturization. Here, we report a paradigm shift in emitter design by demonstrating an efficient, field-free, broadband THz emitter based on a single-layer ferromagnetic alloy. By utilizing chemically disordered, face-centered cubic Fe_<i>x</i>Pt_1−<i>x</i>, we integrate spin current generation and conversion within a single material layer, thereby circumventing the interfacial spin memory loss inherent to traditional bilayer structures. Crucially, the asymmetry at the film’s interfaces enables a net longitudinal current, which is then converted into a transverse THz current by the bulk anomalous Hall effect (AHE) and inverse spin Hall effect (ISHE). The optimized A1-phase Fe₅₀Pt₅₀ composition exhibits a THz emission peak amplitude 1.52 times greater than that of a standard 1-mm-thick ZnTe crystal. This work establishes a simplified, robust, and efficient platform for ultrabroadband THz generation, paving the way for practical applications in spectroscopy, imaging, and nonlinear optics.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"69 11","pages":""},"PeriodicalIF":7.2,"publicationDate":"2026-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149132808","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":"Beam-based approach to verify nuclear hyperfine mixing effect","authors":"Wu Wang,&nbsp;Tao Li,&nbsp;Xu Wang","doi":"10.1007/s11433-026-3050-2","DOIUrl":"10.1007/s11433-026-3050-2","url":null,"abstract":"<div><p>Electromagnetic coupling between a nucleus and its bound electron(s) can induce mixing of nuclear levels—a phenomenon known as nuclear hyperfine mixing (NHM). This effect can greatly enhance light-nucleus interactions and is expected to play a key role in laser-based nuclear control. Although predicted in 1966, NHM has not yet been experimentally confirmed. Here we propose a beam-based scheme to test the NHM effect via collisions between hydrogenlike ²²⁹Th ions (²²⁹Th⁸⁹⁺) and a thin-layer target. This approach avoids the need for resonance tuning and enables detection of prompt ultraviolet photons as a clear experimental signature of NHM. To evaluate the excitation probability of the nuclear isomeric state, we develop, for the first time, nuclear excitation theories that incorporate NHM in both electron- and nucleus-induced processes.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"69 11","pages":""},"PeriodicalIF":7.2,"publicationDate":"2026-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149132809","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":"High-pressure tuning of electrical transport in freestanding iridates across dimensions","authors":"Jingxin Chen,&nbsp;Xiang Huang,&nbsp;Zhihan Qiao,&nbsp;Yuqiang Liu,&nbsp;Jiao Li,&nbsp;Yuxiang Gao,&nbsp;Jiahao Xu,&nbsp;Haiyang Zhang,&nbsp;Deyang Li,&nbsp;Enyang Men,&nbsp;Hangtian Wang,&nbsp;Han Zhang,&nbsp;Jianyu Xie,&nbsp;Guolin Zheng,&nbsp;Yizhou Liu,&nbsp;Ning Hao,&nbsp;Xiaoping Yang,&nbsp;Mingliang Tian,&nbsp;Qun Niu,&nbsp;Lin Hao","doi":"10.1007/s11433-026-3115-4","DOIUrl":"10.1007/s11433-026-3115-4","url":null,"abstract":"<div><p>Flexible control of crystalline dimensionality and pressure is highly desirable for discovering emergent phenomena but has rarely been achieved within a single oxide. Here we develop a high-pressure strategy that enables pressure to be applied to most freestanding oxide thin films. Using this approach, we uncover a pressure-driven semimetal-insulator-metal transition in three-dimensional iridates and a pressure-robust insulating state in the two-dimensional limit. First-principles calculations reveal that the contrasting pressure responses arise from fundamentally different pressure evolutions of the effective electron correlation. While the correlation strength decreases systematically with pressure in two dimensions, it evolves nonmonotonically in three dimensions, first increasing and then decreasing under compression. Our work opens new opportunities to explore dimensionality effects in the pressure response of quantum materials.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"69 12","pages":""},"PeriodicalIF":7.2,"publicationDate":"2026-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149034784","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":"Initialization-free ultralow-power programmable spin-orbit torque logic devices enabled by chirally asymmetric switching","authors":"Qianbiao Liu,&nbsp;Lijun Zhu","doi":"10.1007/s11433-026-3060-7","DOIUrl":"10.1007/s11433-026-3060-7","url":null,"abstract":"<div><p>Spin logic is of great interest for the development of high-performance, non-Von Neumann artificial intelligence chips. Of particular advantage is the programmable spin-orbit torque logic that can achieve the complete set of the 16 Boolean logic operations within a single device in an initialization-free, low-power, and scalable manner, which is, however, a challenge despite the remarkable efforts over more than two decades. Here, utilizing chirally asymmetric switching, we demonstrate an initialization-free, low-power, programmable spin-orbit torque logic device that is capable of the complete set of 16 Boolean logic operations within a single device with only three inputs and the potential of ultralow power of &lt; 1 fJ/bit (as extrapolated from the current pulse width dependent measurements). We also propose the first initialization-free, all-electrical spin-based cascading computing devices, including a half adder, a three-level full adder, a two-level full adder, and a Transfer/NOT selector. These compact and scalable computing devices are enabled by the chirally asymmetric spin-orbit torque switching of a Ta/FeCoB bilayer with a significant perpendicular Dzyaloshinskii-Moriya interaction field. These results pave an intriguing way for the development of next-generation high-performance large-scale in-memory computing chips based on chirally asymmetric spin-orbit torque switching.</p></div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"69 11","pages":""},"PeriodicalIF":7.2,"publicationDate":"2026-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149132860","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}