物理最新文献

{"title":"Structural and electronic properties of CaTiO3 polymorphs and 2D-derived systems: a theoretical investigation","authors":"Marta Loletti,&nbsp;Costanza Borghesi,&nbsp;Riccardo Rurali,&nbsp;Giacomo Giorgi","doi":"10.1140/epjb/s10051-025-00918-1","DOIUrl":"10.1140/epjb/s10051-025-00918-1","url":null,"abstract":"<p>Oxide perovskite materials exhibit intriguing optical and electrical properties that are widely exploited in ceramics and optoelectronic devices. With particular emphasis on its application for photocatalysis, this study aims to theoretically characterize the structural and electronic features of CaTiO₃, both as a stand-alone material and as a possible component in heterostructures. By means of a campaign of <i>ab-initio</i> calculations, we have revised the polymorphic nature of the material through an extensive analysis of its structural and electronic properties. Although standard DFT clearly confirms its intrinsic underestimation in predicting the excited state properties, by applying the recently introduced DFT<span>(-frac{1}{2})</span> method to the bandgap and dispersion calculations, we find very good agreement with experimental reported data. Finally, we include the investigation of dimensionally reduced CaTiO₃-based surfaces and nanosheets, opening the way to interesting possibilities for additional novel supports and photocatalysts with unique features.</p>","PeriodicalId":787,"journal":{"name":"The European Physical Journal B","volume":"98 4","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjb/s10051-025-00918-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143877716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Dynamical stability of bootstrapped Newtonian stars","authors":"Octavian Micu","doi":"10.1140/epjp/s13360-025-06272-6","DOIUrl":"10.1140/epjp/s13360-025-06272-6","url":null,"abstract":"<div><p>We investigate the dynamical stability of bootstrapped Newtonian stars following homologous adiabatic perturbations, focussing on objects of low or intermediate compactness. The results show that for stars with homogeneous densities these perturbations induce some oscillatory behaviour regardless of their compactness, density and adiabatic index, which makes them dynamically stable. In the case or polytropes with density profiles approximated by Gaussian distributions, both stable and unstable behaviours are possible. It was also shown that in the limit in which the profile of the Gaussian density distribution flattens out, the parameter space for which the perturbations result in an oscillatory behaviour increases, which is similar with the case of stars with homogeneous densities.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 4","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjp/s13360-025-06272-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143877721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Microsphere probe for in-situ high-resolution thickness measurement","authors":"Shuai Xing,&nbsp;Xinyu Zhang,&nbsp;Tianci Shen,&nbsp;Lin Dou,&nbsp;Jiaxin Yu,&nbsp;Fuxing Gu","doi":"10.1007/s00340-025-08468-1","DOIUrl":"10.1007/s00340-025-08468-1","url":null,"abstract":"<div><p>Precise thickness measurement of nanometer-scale dielectrics is crucial for the manufacturing and packaging of high-performance integrated optoelectronic devices. Traditional methods, such as atomic force microscopy, ellipsometry, and evanescent wave sensing techniques, are renowned for their precision but face challenges, such as the need for reference surfaces, precise knowledge of the material’s optical properties, and difficulties with large-area, non-uniform measurements. Here, we propose a high-resolution, full-field thickness measurement technique utilizing the evanescent fields of high-order cavity modes in microsphere resonators. By exploiting the discrepancy in sensitivity among different modes, this method directly achieves consistent thickness measurements across extensive lateral dimensions without requiring reference surfaces. Compared to other optical methods, it offers a simple design and efficient readout, while maintaining a precision of about 0.10 nm per nanometer of spectral shift. When combined with optical manipulation and machine learning algorithms, this technique could provide an alternative solution for real-time monitoring of dielectric layers in semiconductor manufacturing.</p></div>","PeriodicalId":474,"journal":{"name":"Applied Physics B","volume":"131 5","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143875292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Background characterization of the CONUS+ experimental location","authors":"E. Sánchez García,&nbsp;N. Ackermann,&nbsp;S. Armbruster,&nbsp;H. Bonet,&nbsp;C. Buck,&nbsp;K. Fülber,&nbsp;J. Hakenmüller,&nbsp;J. Hempfling,&nbsp;G. Heusser,&nbsp;E. Hohmann,&nbsp;M. Lindner,&nbsp;W. Maneschg,&nbsp;K. Ni,&nbsp;M. Rank,&nbsp;T. Rink,&nbsp;I. Stalder,&nbsp;H. Strecker,&nbsp;R. Wink,&nbsp;J. Woenckhaus","doi":"10.1140/epjc/s10052-025-14160-7","DOIUrl":"10.1140/epjc/s10052-025-14160-7","url":null,"abstract":"<div><p>CONUS<span>+</span> is an experiment aiming at detecting coherent elastic neutrino-nucleus scattering (CE<span>(nu )</span>NS) of reactor antineutrinos on germanium nuclei in the fully coherent regime, continuing the CONUS physics program conducted at the Brokdorf nuclear power plant (KBR), Germany. The CONUS<span>+</span> experiment is installed in the Leibstadt nuclear power plant (KKL), Switzerland, at a distance of 20.7 m from the 3.6 GW reactor core, where the antineutrino flux is <span>(1.5cdot 10^{13})</span> s<span>(^{-1})</span> cm<span>(^{-2})</span>. The CE<span>(nu )</span>NS signature will be measured with four point-contact high-purity low energy threshold germanium (HPGe) detectors. A good understanding of the background is crucial, especially events correlated with the reactor thermal power are troublesome, as they can mimic the predicted CE<span>(nu )</span>NS interactions. A large background characterization campaign was conducted during reactor on and off times to find the best location for the CONUS<span>+</span> setup. On-site measurements revealed a correlated, highly thermalized neutron field with a maximum fluence rate of <span>((2.3pm 0.1)cdot 10^{4})</span> neutrons d<span>(^{-1})</span> cm<span>(^{-2})</span> during reactor operation. The <span>(gamma )</span>-ray background was studied with a HPGe detector without shield, paying special attention to the thermal power correlated <span>(^{16})</span>N decay and other neutron capture <span>(gamma )</span>-lines. The muon flux was examined using a liquid scintillator detector measuring (107 ± 3) muons s<span>(^{-1})</span>m<span>(^{-2})</span>, which corresponds to an average overburden of 7.4 m of water equivalent. The new background conditions in CONUS<span>+</span> are compared to the previous CONUS ones, showing a 30 times higher flux of neutrons, but a 26 times lower component of reactor thermal power correlated <span>(gamma )</span>-rays over 2.7 MeV. The lower CONUS<span>+</span> overburden increases the number of muon-induced neutrons by 2.3 times and the flux of cosmogenic neutrons. Finally, all the measured rates are discussed in the context of the CONUS<span>+</span> background, together with the CONUS<span>+</span> modifications performed to reduce the impact of the new background conditions at KKL.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 4","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14160-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143875404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Perturbative quantum Monte Carlo calculation with high-fidelity nuclear forces","authors":"Jun Liu,&nbsp;Teng Wang,&nbsp;Bing-Nan Lu","doi":"10.1140/epja/s10050-025-01568-8","DOIUrl":"10.1140/epja/s10050-025-01568-8","url":null,"abstract":"<div><p>Quantum Monte Carlo (QMC) is a family of powerful tools for addressing quantum many-body problems. However, its applications are often plagued by the fermionic sign problem. A promising strategy is to simulate an interaction without sign problem as the zeroth order and treat the other pieces as perturbations. According to this scheme, we construct precision nuclear chiral forces on the lattice and make perturbative calculations around a sign-problem-free interaction respecting the Wigner-SU4 symmetry. We employ the recently developed perturbative QMC (ptQMC) method to calculate the perturbative energies up to the second order. This work presents the first ptQMC calculations for two-body next-to-next-to-next-to leading order (<span>(hbox {N}^3)</span>LO) chiral forces and elucidates how the hierarchical nature of the chiral interactions helps organize and simplify the ptQMC calculations. We benchmark the algorithm for the deuteron, where exact solutions serve as rigorous reference points. We also reproduce the famous Tjon line by correlating the perturbative <span>(^{4})</span>He binding energies with the non-perturbative <span>(^{3})</span>H binding energies. These comprehensive demonstrations underscore the efficacy of ptQMC in resolving high-fidelity nuclear interactions, establishing its potential as a robust tool for <i>ab initio</i> nuclear structure studies.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 4","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143875406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Lattice calculation of the (eta _ceta _c) and (J/psi J/psi ) s-wave scattering length","authors":"Yu Meng,&nbsp;Chuan Liu,&nbsp;Xin-Yu Tuo,&nbsp;Haobo Yan,&nbsp;Zhaolong Zhang","doi":"10.1140/epjc/s10052-025-14192-z","DOIUrl":"10.1140/epjc/s10052-025-14192-z","url":null,"abstract":"<div><p>We calculate the s-wave scattering length in the <span>(0^+)</span> sector of <span>(eta _ceta _c)</span> and the <span>(2^+)</span> sector of <span>(J/psi J/psi )</span> using three <span>(N_f=2)</span> twisted mass gauge ensembles with the pion mass <span>(300{-}365)</span> MeV and lattice spacing <span>(a=0.0667,0.085,0.098)</span> fm, respectively. The scattering lengths are extracted using the conventional Lüscher finite size method. We observe sizable discretization effects and the results after a continuum extrapolation are <span>(a^{0^+}_{eta _ceta _c}=-0.104(09))</span> fm and <span>(a^{2^+}_{J/psi J/psi }=-0.165(16))</span> fm. The slight difference of light quark mass is ignored in this study. Our results indicate that the interaction between the two respective charmonia are repulsive in nature in both cases.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 4","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14192-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Confined but chirally and chiral spin symmetric hot matter","authors":"L. Ya. Glozman,&nbsp;A. V. Nefediev,&nbsp;R. F. Wagenbrunn","doi":"10.1140/epjc/s10052-025-14164-3","DOIUrl":"10.1140/epjc/s10052-025-14164-3","url":null,"abstract":"<div><p>We investigate properties of the quark–antiquark mesons at zero and finite temperature in the framework of a solvable chirally symmetric quark model. The interquark linearly rising interaction is reminiscent of that derived in Coulomb gauge QCD, with the string tension being the only model parameter. We demonstrate that while the confining interaction induces spontaneous breaking of chiral symmetry at <span>(T=0)</span>, it gets restored at a temperature <span>(T_textrm{ch}simeq 90)</span> MeV for the string tension fixed to provide the phenomenological value of the quark condensate. This temperature is similar to <span>(T_textrm{ch}simeq 130)</span> MeV observed on the lattice in the chiral limit for <span>(N_c=3)</span>. The physical mechanism responsible for chiral symmetry restoration in the confining regime is Pauli blocking of the quark levels, required for the existence of a nonvanishing quark condensate, by thermal excitations of the quarks and antiquarks. Thus, above the chiral restoration temperature, meson-like states are chirally symmetric and approximately chiral spin symmetric. A crucial property of the confined meson-like light-light states above <span>(T_textrm{ch})</span> is their size that exceeds drastically that in the chirally broken phase below <span>(T_textrm{ch})</span>. Heavy-heavy mesons nearly preserve their size irrespective of the temperature. Furthermore, the root-mean-square radius of the states with <span>(J=0,1)</span> diverges in the chiral limit. This unexpected property must be a key to understanding unusual features of the hot QCD matter as observed at RHIC and LHC. Consequently, the confining but chirally symmetric matter above <span>(T_textrm{ch})</span> can be considered as a dense system of very large and strongly overlapping meson-like states (“strings”).\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 4","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14164-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143875335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Exploring decoupling process and energy exchange in compact stars induced by dark matter spike density profile within complexity free domain","authors":"S. K. Maurya,&nbsp;Sweeti Kiroriwal,&nbsp;Jitendra Kumar,&nbsp;Abdul Aziz","doi":"10.1140/epjc/s10052-025-14151-8","DOIUrl":"10.1140/epjc/s10052-025-14151-8","url":null,"abstract":"<div><p>This study focuses on the characteristics of compact stars composed of dark matter induced by gravitational decoupling in the context of the general theory of relativity. We are proposing an anisotropic model holding an Einasto spike dark matter density profile. The vanishing complexity factor along with a complete geometric deformation approach has been used to solve the decoupled field equations for the spherically symmetric celestial objects. In the current decoupled solution, the decoupling parameter <span>(beta )</span> determines the quantity of dark matter content inside the object. Additionally, we determine the model’s physical quantities such as pressure, density, anisotropy, causality criteria, energy exchange between the fluid distributions, and variation of mass with central density mass within the stellar model PSR J0952-0607 for different values of <span>(beta )</span> which shows the impact of dark matter content on these physical quantities. Furthermore, we have also shown the influence of <span>(beta )</span> on the radii of the astrophysical binary pulsars GW190814, PSR J0952-0607, and PSR J1614-2230. In the framework of the decoupling approach, our graphical findings show that binary pulsars have mass lower than <span>(M_{max})</span> but higher radii for a specific <span>(M{-}R)</span> curve for well-defined values of given parameters.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 4","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14151-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Topological insights into black hole thermodynamics: non-extensive entropy in CFT framework","authors":"Mohammad Ali S. Afshar,&nbsp;Mohammad Reza Alipour,&nbsp;Saeed Noori Gashti,&nbsp;Jafar Sadeghi","doi":"10.1140/epjc/s10052-025-14173-2","DOIUrl":"10.1140/epjc/s10052-025-14173-2","url":null,"abstract":"<div><p>In this paper, we conducted an in-depth investigation into the thermodynamic topology of Einstein-Gauss-Bonnet black holes within the framework of Conformal Field Theory (CFT), considering the implications of non-extensive entropy formulations. Our study reveals that the parameter <span>(lambda )</span> (Rényi entropy) plays a crucial role in the phase behavior of black holes. Specifically, when <span>(lambda )</span> is below the critical value (C), it has a negligible impact on the phase behavior. However, when <span>(lambda )</span> exceeds the critical value, it significantly alters the phase transition outcomes. Determining the most physically representative values of <span>(lambda )</span> will require experimental validation, but this parameter flexibility allows researchers to better explain black hole phase transitions under varying physical conditions. Furthermore, the parameters <span>(alpha )</span> and <span>(beta )</span> affect the phase structure and topological charge for the Sharma–Mittal entropy. Only in the case of <span>(C&gt;C_c)</span> and in the condition of <span>(alpha approx beta )</span> will we have a first-order phase transition with topological charge + 1. Additionally, for the loop quantum gravity (LQG) non-extensive entropy as the parameter <i>q</i> approaches 1, the classification of topological charges changes. We observe configurations with one and three topological charges with respect to critical value <i>C</i>, resulting in a total topological charge <span>(W = +1)</span>, and configurations with two topological charges <span>((omega = +1, -1))</span>, leading to a total topological charge <span>(W = 0)</span>. These findings provide new insights into the complex phase behavior and topological characteristics of black holes in the context of CFT and non-extensive entropy formulations.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 4","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14173-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Macroscopic entanglement generation and transfer in a coupled cavity–magnon system via optical parametric amplifier","authors":"Yuan Shun,&nbsp;Zhang Yunpeng,&nbsp;Chang Guohao,&nbsp;Hunduzi Halimjan,&nbsp;Ahmad Abliz","doi":"10.1140/epjp/s13360-025-06274-4","DOIUrl":"10.1140/epjp/s13360-025-06274-4","url":null,"abstract":"<div><p>Generation and transfer of quantum entanglement at macroscopic scales are key for advancing quantum information processing and communication. This paper presents a theoretical framework for achieving and transferring bipartite and tripartite entanglement in a coupled cavity–magnon system integrated with an optical parametric amplifier (OPA). The findings indicate that in the four-mode system under study, the nonlinear gain introduced by the OPA facilitates the creation of bipartite entanglement. This bipartite entanglement, produced by two coupled microwave cavities, is driven concurrently by the squeezing effects of the OPA and transferred to two magnons through cavity–magnon coupling. The transfer rate of this entanglement increases with the strength of the linear cavity–magnon coupling and approaches unity. The magnon–magnon entanglement produced can be tuned using parameters such as the cavity–cavity coupling strength, the cavity dissipation rate, and the nonlinear gain coefficient of the OPA. Additionally, this entanglement shows robustness to temperature. Under steady-state conditions, the system achieves tripartite entanglement in both cavity–magnon–cavity and magnon–cavity–magnon configurations, and the OPA nonlinear effects improve the system's resilience to temperature fluctuations.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 4","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}