物理最新文献

{"title":"Optimal control fields for efficient quantum memory in cold atoms via EIT","authors":"Poonam Yadav,&nbsp;Arnab Ghosh,&nbsp;Inderpreet Kaur,&nbsp;Suranita Kanjilal,&nbsp;Bodhaditya Santra","doi":"10.1140/epjd/s10053-025-01056-0","DOIUrl":"10.1140/epjd/s10053-025-01056-0","url":null,"abstract":"<p>Quantum memory is an indispensable component for enabling reliable long-distance quantum communication through quantum repeaters. In this work, we present a theoretical study of quantum memory based on electromagnetically induced transparency in a cold ensemble of Cesium atoms. We analyze the quantum memory performance by examining its dependence on the control field Rabi frequency (<span>(varOmega _c)</span>) and the atomic optical depth (D). Our results show that high storage efficiency can be achieved at larger values of both <span>(varOmega _c)</span> and D. Furthermore, we calculate the group velocity of slow light and investigate the decoherence rate in the hyperfine ground states used as storage levels. Notably, the decoherence rate decreases as <span>(varOmega _c)</span> increases and eventually saturates. These findings offer useful insights into optimizing EIT-based quantum memory and advancing practical implementations of quantum communication networks.</p>","PeriodicalId":789,"journal":{"name":"The European Physical Journal D","volume":"79 9","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144998417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Fluctuations of local plastic strain in granular media","authors":"I. Awada,&nbsp;M. Bornert,&nbsp;V. Langlois,&nbsp;J. Léopoldès","doi":"10.1140/epje/s10189-025-00515-1","DOIUrl":"10.1140/epje/s10189-025-00515-1","url":null,"abstract":"<div><p>We experimentally study the heterogeneity of strain in a granular medium subjected to oscillatory shear in a rotating drum. Two complementary methods are used. The first method relies on optical imaging and grain tracking, allowing us to compute some components of the strain tensor and their variance. The second method, diffuse acoustic wave spectroscopy (DAWS), provides the quadratic strain within the bulk. Our results show that strain is spatially heterogeneous, with fluctuations about ten times larger than the mean, primarily dominated by variability at the grain scale. We then analyze in detail the strain fluctuations occurring during the forward and backward branches of the shear stress cycles, along with the intracycle plastic strain resulting from each cycle. Both methods reveal that each shear cycle consists of two consecutive diffusive-like branches, and that the resulting plastic strain fluctuations scale with the mean plastic shear strain. We propose that plastic strain fluctuations result from irreversible strain heterogeneity that increases with applied shear—reflected in forward–backward strain anticorrelations—but is constrained by load-controlled induced memory.</p></div>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"48 8-9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144998546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"In vivo mimicking multiphase model towards impact of host on avascular tumour growth","authors":"Abdush Salam Pramanik,&nbsp;Bibaswan Dey,&nbsp;G. P. Raja Sekhar","doi":"10.1140/epje/s10189-025-00517-z","DOIUrl":"10.1140/epje/s10189-025-00517-z","url":null,"abstract":"<p>Tumour growth involves dynamic interactions among tumour cells, extracellular materials, and host tissue. The tumour exerts mechanical stresses on the host tissue and simultaneously experiences compression across the tumour–host interface. This article presents a mathematical model that mimics an in vivo set-up, where an avascular tumour is surrounded by healthy/normal tissue, utilizing conservation principles for the constituents in each region. Tumour and host tissues are separately treated as biphasic mixtures comprising cells and extracellular materials. This study incorporates the diffusion-dominated transport and metabolism of cell-nourishing agents (<i>CNA</i>), such as oxygen, nutrients, and growth factors. The mechanical impact of normal host tissue on tumour growth dynamics while maintaining stress continuity at the tumour–host interface is analysed through numerical simulations. The key findings are that when <i>CNA</i> levels decline below a specific threshold, the tumour cell volume fraction decreases from the periphery to the centre, resulting in necrotic cell death alongside apoptosis. This study indicates that host tissue reduces <i>CNA</i> tension, accelerating tumour necrosis. The increased viscosity of normal host cells indicates stronger intercellular bonds, causing the cells to adhere more tightly and stiffen the host. With increasing viscosity-induced resistance, the host tissue more effectively impedes tumour expansion, thereby slowing tumour growth due to rising compressive stress. Analytical results for a solvable scenario are also provided to explore the comparative behaviour with numerical simulations of the complete model. Furthermore, analytical results indicate that an increased viscosity of normal host tissue may delay the initiation of necrotic cell death.</p><p>Higher host cell viscosity lowers the growth rate of an in vivo tumour</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"48 8-9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Fabrication and tuning of the morphological, structural, and dielectric features of PVA/SnO2-SiC ternary nanocomposites for multifunctional nanoelectronics applications","authors":"Ali Hussein Kareem,&nbsp;Majeed Ali Habeeb","doi":"10.1140/epjp/s13360-025-06790-3","DOIUrl":"10.1140/epjp/s13360-025-06790-3","url":null,"abstract":"<div><p>The objective of this study is to improve the dielectric characteristics of polyvinyl alcohol (PVA), tin dioxide (SnO₂), as well as silicon carbide (SiC) in order to facilitate the functionality of electronics nanodevices and flexible pressure sensors. The nanocomposites PVA/SnO₂-SiC were prepared by casting with varied concentrations of (SnO₂-SiC) nanoparticles (0, 2, 4, 6, and 8) wt.%. The structure and dielectric characteristics of PVA/SnO₂-SiC nanostructures were explored. The optical microscopy images showed that network paths that act as charge carriers are formed inside the polymeric matrix with increasing concentrations of nanoparticles. The outcomes of the SEM measurement indicated that the surface morphology was uniform and well-distributed. X-ray analysis shows that the (SnO₂-SiC) nanoparticles increase in the polymeric specimens, and the semi-crystalline ratio rises. The electrical properties of PVA/SnO₂-SiC films revealed that the dielectric (constant and loss) increases with increasing nanoparticle concentrations and decreases when the frequency of the applied electric field increases. In contrast, the A.C electrical conductivity increases by increasing the frequency and concentrations of (SnO₂-SiC). Finally, the structural and dielectric properties show that the PVA/SnO₂-SiC nanocomposite films can be employed in various flexible nanoelectronics applications with low cost, high-energy storage and low loss. The pressure sensor results of PVA/SnO₂-SiC nanostructures showed that their electrical capacitance (Cp) grows as applied pressure rises. As a result, pressure sensors have a higher sensitivity. Based on these findings, it is believed that PVA/SnO₂-SiC nanocomposites may provide new insight into their potential application in energy storage systems.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144998392","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":"Quantifying the mixing behavior of direct injected hydrogen in high-pressure environments by Rayleigh scattering","authors":"Max Peters,&nbsp;Noud Maes,&nbsp;Nico Dam,&nbsp;Jeroen van Oijen","doi":"10.1007/s00340-025-08549-1","DOIUrl":"10.1007/s00340-025-08549-1","url":null,"abstract":"<div><p>In the framework of the Argon Power Cycle, millisecond-pulsed hydrogen gas injections into a high-pressure, room temperature nitrogen or argon ambient are investigated. Instantaneous Rayleigh scattering is used to quantify the hydrogen mole fraction in the ensuing jets. A readily available HDEV injector with a straight 0.55-mm orifice and an inward-moving needle controls the mass flow into the constant-volume setup in accordance with (compressible) choked flow theory. The linear dependence of the Rayleigh signal on the number density is experimentally validated and the validity for the assumed constant number density throughout the mixing jet is presented. The evolution of mole fraction is presented for both nitrogen and argon ambient gases, and pressure ratios of 2.5 and 10. Quasi-steady behavior is shown in both axial and radial direction, while self-similar behavior is already observed 3 mm from the nozzle (<span>(x/d_textrm{e} = 5.5)</span>).</p></div>","PeriodicalId":474,"journal":{"name":"Applied Physics B","volume":"131 10","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00340-025-08549-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144998564","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":"Thorough DFT design of 2D single and multilayers and 1D zigzag (n,0) single-walled nanotube platinum disulfide (PtS2)","authors":"T. Larbi,&nbsp;K. Doll,&nbsp;M. Amlouk","doi":"10.1140/epjp/s13360-025-06784-1","DOIUrl":"10.1140/epjp/s13360-025-06784-1","url":null,"abstract":"<div><p>In this contribution, we focus on the simulation of stable low dimensional (1D, 2D) platinum disulfide (PtS₂). Its structural and dynamic properties are obtained by employing density functional theory (DFT) at the B3LYP level of theory, with dispersion taken into account with an empirical correction (D3). Geometry optimizations combined with the calculation of the elastic tensor elements reveal that the 2D monolayer, multi-layers and the 1D rolled up (<i>n</i>,0) zigzag single-walled nanotube family of PtS₂ are mechanically stable. Then, IR and Raman spectra were simulated by using the coupled perturbed Hartree–Fock/Kohn–Sham CPHF/KS approach which confirms dynamic stability of all considered PtS₂ modifications. Quantum confinement from the 3D bulk to 2D single and multi-layers breaks the symmetry and affects the lattice dynamics. Two groups of phonon modes are present in the IR and Raman spectra of the (<i>n</i>,0) zigzag nanotube family. In the frequency range from 200 to 400 cm⁻¹, by increasing the tube diameter the active modes of the (<i>n</i>,0) PtS₂ nanotubes tend to those of the 1 T single layer. Our simulation offers a pathway for the design of dynamic stable low dimensional transition metal dichalcogenides, and paves the way to a broader investigation on such 2D and 1D nanomaterials.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005497","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":"Critical scaling for spectral functions","authors":"Konrad Kockler,&nbsp;Jan M. Pawlowski,&nbsp;Jonas Wessely","doi":"10.1140/epjc/s10052-025-14679-9","DOIUrl":"10.1140/epjc/s10052-025-14679-9","url":null,"abstract":"<div><p>We study real-time scalar <span>(phi ^4)</span>-theory in 2+1 dimensions near criticality. Specifically, we compute the single-particle spectral function and that of the <i>s</i>-channel four-point function in and outside the scaling regime. The computation is done with the spectral functional Callan–Symanzik equation, which exhibits manifest Lorentz invariance and preserves causality. We extract the scaling exponent <span>(eta )</span> from the spectral function and compare our result with that from a Euclidean fixed point analysis.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 9","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14679-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005536","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":"Feedback-driven model of dynamic information spreading in online social networks","authors":"Fuzhong Nian,&nbsp;Jingru Niu,&nbsp;Zhen Wang","doi":"10.1007/s12043-025-02999-0","DOIUrl":"10.1007/s12043-025-02999-0","url":null,"abstract":"<div><p>This paper constructs a spreading model driven by positive and negative feedback interactions to study the impact of inter-individual feedback interaction on message spreading in online social networks. By analysing the network topology and the social attributes of the propagators, we introduce feedback interaction rules. In addition, the individual’s spreading motivation comes from the direct feedback interactions of multilevel neighbours and the group-level pressure of the social environment. Therefore, we established a feedback efficiency function. Experimental results show that the model is effective in promoting the positive spread of messages. Meanwhile, it is found that the increased social distance between individuals weakens the feedback strength, the group feedback rate enhances the expected spreading ability of the upline nodes and the group feedback has a more significant incentive effect than the neighbour feedback. Finally, the reasonableness of the model is verified by comparing with real cases.</p></div>","PeriodicalId":743,"journal":{"name":"Pramana","volume":"99 4","pages":""},"PeriodicalIF":2.1,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Scrambling in charged hairy black holes and the Kasner interior","authors":"Hadyan Luthfan Prihadi,&nbsp;Donny Dwiputra,&nbsp;Fitria Khairunnisa,&nbsp;Freddy Permana Zen","doi":"10.1140/epjc/s10052-025-14625-9","DOIUrl":"10.1140/epjc/s10052-025-14625-9","url":null,"abstract":"<div><p>We analyze how the axion parameter, the Einstein–Maxwell-Scalar (EMS) coupling constant, and the charge density affect the chaotic properties of a charged hairy black hole, as characterized by the quantum Lyapunov exponent. We inject charged shock waves from the asymptotic boundary and compute the out-of-time-ordered correlators (OTOCs). Due to the relevant deformation in the boundary theory induced by a bulk scalar field, the bulk solution flows to a more general Kasner spacetime near the black hole singularity. We examine the behavior of chaotic parameters, including the Lyapunov exponent, butterfly velocity, and scrambling time delay, under this deformation. We find that as the deformation parameter increases, the ratio of the quantum Lyapunov exponent to the surface gravity decreases. For sufficiently large deformation, the Lyapunov exponent in the deformed geometry can exceed that of the axion Reissner–Nordström case. We observe that boundary deformation generally reduces the scrambling time delay, with the EMS coupling having a significant effect on the delay. These results provide further insight into the role of boundary deformations in modifying chaotic properties in charged hairy black holes.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 9","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14625-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144990462","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":"Charmonium spectrum and its decay properties","authors":"Zaki Ahmad,&nbsp;Ishrat Asghar,&nbsp;Bilal Masud,&nbsp;M. Atif Sultan","doi":"10.1140/epja/s10050-025-01671-w","DOIUrl":"10.1140/epja/s10050-025-01671-w","url":null,"abstract":"<div><p>In this work, we have calculated the mass spectrum, radiative decays, and strong decays of charmonium (<span>(coverline{c})</span>) by using the non-relativistic quark potential (NRQP) model. The wave functions are calculated by solving the radial Schrödinger equation numerically, which are further used to compute the radiative decay widths of (<span>(coverline{c})</span>) states. The <span>(^3P_0)</span> model is used to calculate the strong decay widths by using the simple harmonic (SHO) wave functions. The SHO parameter <span>(beta )</span> values for different <span>(coverline{c})</span> states are calculated by fitting it to the numerical wave functions. We also compare our results with experimental data and other theoretically predicted results. We assign to the charmonium states X(3940), X(3872), X(3862), X(4350) likely quantum numbers of <span>(eta _c(3S))</span>, <span>(chi _1(2P))</span>, <span>(chi _0(2P))</span> and <span>(chi _2(3P))</span> states.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 9","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144990536","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}