物理最新文献

{"title":"Electrical conductivity and transport mechanisms in Bi-, Cu-, and W-doped BFN ceramic: a theoretical approach","authors":"Manel Amara,&nbsp;Fahad N. Almutairi,&nbsp;Nadi Mlihan Alresheedi,&nbsp;J. Dhahri","doi":"10.1140/epjp/s13360-025-06212-4","DOIUrl":"10.1140/epjp/s13360-025-06212-4","url":null,"abstract":"<div><p>The perovskite complex 0.985(BaFe_0.5Nb_0.5O₃)-0.015(BiCu_0.75W_0.25O₃) (0.985BFN-0.015BCW) was successfully prepared using the solid-state reaction technique. The X-ray diffraction patterns reveal that the prepared sample crystallizes in cubic symmetry. Our paper provides an insight into the electrical transport behavior of our compound. Indeed, different conduction models are applied to interpret the electrical conductivity response. It was observed that the transport properties are influenced by hopping mechanisms across different temperature ranges, which explains both the changes in DC conductivity and the movement of charge carriers with temperature variations. This confirms that the charge carriers undergo thermal activation. The variation of the exponent s as a function of temperature indicates the presence of Quantum Mechanical Tunneling (QMT), Correlated Barrier Hopping (CBH), Non-overlapping Small Polaron Tunneling (NSPT), and Overlapping Large Polaron Tunneling (OLPT) in the transport properties. At the temperature range [160–540 K], the AC conductivity is found to obey “double Jonscher power law.” Besides, the frequency dependence of the conductivity obeys “single Jonscher power law” at higher temperatures. Additionally, the conductivity spectrum shows a high-frequency plateau, which suggests percolation behavior.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"140 4","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761766","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":"Correction: NiO nanosheet-assembled chemiresistive sensor for NO2 detection","authors":"Ravishankar R. Ambi,&nbsp;Rahul A. Mali,&nbsp;Aniket B. Pawar,&nbsp;Moshim G. Mulla,&nbsp;Raj K. Pittala","doi":"10.1007/s00339-025-08466-2","DOIUrl":"10.1007/s00339-025-08466-2","url":null,"abstract":"","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 5","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Notable peak voltage and sensitivity as well as optical-communication of the inclined Bi2Sr2CuOy thin film with different wavelength lasers","authors":"Xianwu Tang,&nbsp;Yanchao Zhang,&nbsp;Ming Liu,&nbsp;Yuxuan Jiang,&nbsp;Xueyao Lu,&nbsp;Gangyi Zhu,&nbsp;Yongjin Wang,&nbsp;Xuebin Zhu","doi":"10.1007/s00339-025-08484-0","DOIUrl":"10.1007/s00339-025-08484-0","url":null,"abstract":"<div><p>In this work, the laser-induced thermoelectric voltage (LITV) of the solution-deposited inclined Bi₂Sr₂CuO_y (BSCO) thin films with different wavelength semiconductor lasers was investigated. Microstructure results indicate the BSCO thin film inclined growth along the substrate with the same angle. Obvious LITV keeps a linear increase with the increased power density for each wavelength laser. The peak voltage is over 40 mV at the power density of 40 mW/cm². It is slightly different with the laser wavelength, caused by the difference in optical absorption and light penetration depth. The sensitivity is higher than 0.8 and increases to 1.15 V·cm²/W with the laser changes from green to ultraviolet. Furthermore, based on the LITV effect of the BSCO thin film, the carry information can be transmitted and decoded correctly via the optical communications system composed of the light diode laser. All these results demonstrate the potential application and favorable properties of the inclined BSCO thin films in broad-spectrum response of photodetection.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 5","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gravitational Faraday holonomy","authors":"Blake A. Parvin,&nbsp;Mark T. Lusk","doi":"10.1140/epjc/s10052-025-14086-0","DOIUrl":"10.1140/epjc/s10052-025-14086-0","url":null,"abstract":"<div><p>Closed optical trajectories in Kerr spacetime are engineered to exhibit a marked lack of symmetry. The eccentricity manifests as a holonomy in gravitational Faraday rotation that can be made arbitrarily large by radial translation of the common location of source and receiver. All trajectories are non-equatorial and include a passage through the equatorial plane at the radial turning point, where the trajectory and pseudo-magnetic field are well-aligned. This, combined with path asymmetry, results in a large gravitational Faraday holonomy that lends itself to experimental measurement. Trajectories that start further away from the singularity pass more closely to the ergosphere, thus transiting a more distorted region of spacetime with concomitant amplification of gravitational Coriolis force.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 4","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14086-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749158","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":"Detect anomalous quartic gauge couplings at muon colliders with quantum kernel k-means","authors":"Shuai Zhang,&nbsp;Ke-Xin Chen,&nbsp;Ji-Chong Yang","doi":"10.1140/epjc/s10052-025-14069-1","DOIUrl":"10.1140/epjc/s10052-025-14069-1","url":null,"abstract":"<div><p>In recent years, with the increasing luminosities of colliders, handling the growing amount of data has become a major challenge for future New Physics (NP) phenomenological research. In order to improve efficiency, machine learning algorithms have been introduced into the field of high-energy physics. As a machine learning algorithm, kernel k-means has been demonstrated to be useful for searching NP signals. It is well known that the kernel k-means algorithm can be carried out with the help of quantum computing, which suggests that quantum kernel k-means (QKKM) is also a potential tool for NP phenomenological studies in the future. This paper investigates how to search for NP signals using QKKM. Taking the <span>(mu ^+mu ^-rightarrow nu {bar{nu }}gamma gamma )</span> process at a muon collider as an example, the dimension-8 operators contributing to anomalous quartic gauge couplings (aQGCs) are studied. The expected coefficient constraints obtained using the QKKM of three different forms of quantum kernels, as well as the constraints obtained by the classical k-means algorithm are presented, and it can be shown that QKKM can help to find the signal of aQGCs. Comparing the classical k-means anomaly detection algorithm with QKKM, it is indicated that the QKKM is able to archive a better cut efficiency.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 4","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14069-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761813","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":"Laboratory constraint on the electric charge of the neutron and the neutrino","authors":"Savely G. Karshenboim","doi":"10.1140/epjd/s10053-025-00964-5","DOIUrl":"10.1140/epjd/s10053-025-00964-5","url":null,"abstract":"<p>We revisit constraints on the value of the electric charge of the neutron and the neutrinos as well as on the electric-charge proton–electron difference <span>(e_p+e_e)</span>. We consider phenomenological constraints based on laboratory study of the electrical neutrality of would-be neutral subatomic, atomic, and molecular species under assumption of the conservation of the electric charge in the <span>(beta )</span> decay that relates the values of <span>(e_p+e_e, e_n, e_nu )</span>. Some of constraints published previously utilized an additional assumption <span>(e_nu =0)</span>, which we do not. We dismiss a cosmological constraint at the level of <span>(10^{-35},e)</span> utilized by Particle Data Group (PDG) in their <i>Review of particle properties</i> Workman et al. (Particle Data Group) (Prog Theor Exp Phys 2022:083C01, 2022) as a controversial one which makes the laboratory constraints on <span>(e_nu )</span> dominant. The phenomenological constraints from the available data of laboratory experiments are obtained as <span>(e_p+e_e=(0.2pm 2.6)times 10^{-21},e)</span>, <span>(e_n=(-0.4pm 1.1)times 10^{-21},e)</span>, and <span>(e_nu =(0.6pm 3.2)times 10^{-21},e)</span>. The ones on <span>(e_p+e_e)</span> and <span>(e_n)</span> are at the same level as the related constraints of PDG but somewhat different because of releasing the value of <span>(e_nu )</span>. Our <span>(e_nu )</span> constraint is several orders of magnitude weaker than the controversial cosmological result dominated in the PDG constraint, but several orders of magnitude stronger than the other individual <span>(e_nu )</span> constraints considered by PDG. We also consider consistency of the phenomenological constraints and the Standard Model (SM). The SM ignores the mass term of the neutrinos and cannot describe the neutrino oscillations which makes it not a complete theory but a part of it. We demonstrate that the condition of the cancellation of the triangle anomalies within the complete theory does not disagree with the phenomenological constraints since different extensions of the SM may produce different additional contributions to the anomalies. A choice of the extension fixes the way how those contributions are organized. In particular, we consider a minimal extension of the SM, where leptons (<span>(nu ,e)</span>) are treated the same ways as quarks, which sets <span>(e_p+e_e=0)</span> and allows for numerical strengthening the constraint on <span>(e_n)</span> and <span>(e_nu )</span>, which is <span>(e_n=-e_nu =(-0.4pm 1.0)times 10^{-21},e)</span>.</p><p>Phenomenological constraint on the value of the electric charge of the neutrino</p>","PeriodicalId":789,"journal":{"name":"The European Physical Journal D","volume":"79 4","pages":""},"PeriodicalIF":1.5,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjd/s10053-025-00964-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749061","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":"Some simple theories of gravity with propagating nonmetricity","authors":"Yusuke Mikura,&nbsp;Roberto Percacci","doi":"10.1140/epjc/s10052-025-14036-w","DOIUrl":"10.1140/epjc/s10052-025-14036-w","url":null,"abstract":"<div><p>We investigate symmetric metric-affine theories of gravity with a Lagrangian containing all operators of dimension up to four that are relevant to free propagation in flat space. Complementing recent work in the antisymmetric case, we derive the conditions for the existence of a single massive particle with good properties, in addition to the graviton.\u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 4","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14036-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761721","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":"Controlled co-precipitation synthesis of Gd and Mn doped zinc tungstate: insights into structural, optical, magnetic behavior, and dielectric properties","authors":"Sadegh Azadmehr,&nbsp;Sanaz Alamdari,&nbsp;Majid Jafar Tafreshi,&nbsp;Zaighum Tanveer,&nbsp;Omid Mirzaee,&nbsp;Aliasghar Najafzadehkhoee,&nbsp;Jose J. Velázquez","doi":"10.1007/s00339-025-08399-w","DOIUrl":"10.1007/s00339-025-08399-w","url":null,"abstract":"<div><p>Gadolinium and manganese-doped zinc tungstate (ZnWO₄: Gd &amp; ZnWO₄: Mn (1 at%)) nanocrystals were successfully prepared using a simple co-precipitation method. The structural, morphological, and chemical properties of the materials were thoroughly investigated using X-ray diffraction (XRD), scanning/transmission electron microscopy (SEM/TEM), and energy dispersive X-ray (EDX) analysis. The crystallite sizes of the Gd-doped and Mn-doped samples were 46 nm and 59 nm, respectively. XRD analysis confirmed that both samples exhibited a single monoclinic phase crystal structure. The Gd-doping resulted in a more uniform particle size distribution and smoother surface morphology, which could enhance the optical and magnetic properties of the material. In contrast, Mn-doping led to the formation of more agglomerated particles with a rougher texture, potentially affecting the specific surface area and its interaction with external fields. SEM/TEM images also revealed an increase in average particle size with the Mn dopant. Optical properties, as measured by diffuse reflectance spectroscopy (DRS), showed a band gap of 3.79 eV for ZnWO₄: Gd and 3.40 eV for ZnWO₄: Mn. Magnetic measurements indicated enhanced magnetic properties for ZnWO₄: Mn compared to both pure ZnWO₄ and ZnWO₄: Gd. The dielectric properties, including the dielectric constant (εr), dielectric loss (tan δ), and AC conductivity, were studied over a frequency range from 100 Hz to 3 MHz at room temperature. The reduced coercivity observed in the Mn-doped sample suggests improved performance for potential applications in transformers, windings, and magnetic storage devices, where reduced core loss and enhanced efficiency are key requirements.This study not only enhances the understanding of the influence of Gd and Mn doping on ZnWO₄ properties but also opens up new possibilities for the development of multifunctional materials for advanced technological applications.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"131 5","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nonmetricity-based hybrid self-gravitating compact stars with embedded class-one symmetry","authors":"Naveed Iqbal,&nbsp;S. Khan,&nbsp;Mohammad Alshammari,&nbsp;Wael W. Mohammed,&nbsp;M. Ilyas","doi":"10.1140/epjc/s10052-025-14102-3","DOIUrl":"10.1140/epjc/s10052-025-14102-3","url":null,"abstract":"<div><p>This work aims to explore the novel characteristics of a static hybrid transitional star with a spherical distribution of relativistic matter under the embedded class one metric framework. This theoretical stellar model is derived using the nonmetricity-inspired <span>(f(mathbb {Q}))</span> gravity, featuring a core-crust structure: a strange matter core embedded in a normal matter crust. Our model incorporates pressure anisotropy as an intrinsic characteristic of highly compact strange stars, a feature expected to arise in the super-dense regime. The equation of state, in its basic form, using the MIT bag model is employed to represent correlation between pressure and density in quark matter inside the star’s core. The development of this model involves selecting the temporal gravitational potential based on the Tolman–Kuchowicz ansatz, while the radial gravitational potential is determined using the Class One embedding formalism. We employed both analytical and graphical methods to assess the robustness and equilibrium of the presented stellar solution. We provide an in-depth description of the astrophysical features of the model and show that they fulfill regularity requirements. A key finding of this investigation is the absence of a core singularity within the anisotropic stellar formation. The solution matches the properties of the observed self-gravitating pulsar objects: SAX J1804.4-3658 (SS1), EXO1745-248, 4U1820-30, 4U1608-52, PSR J0740+6620, PSR J0030+0451, Cen X-4, and SAX J1804.4-3658 (SS2). \u0000</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 4","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14102-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749130","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":"Reconciling fractional entropy and black hole entropy compositions","authors":"Manosh T. Manoharan,&nbsp;N. Shaji","doi":"10.1140/epjc/s10052-025-14107-y","DOIUrl":"10.1140/epjc/s10052-025-14107-y","url":null,"abstract":"<div><p>This study investigates the implications of adopting fractional entropy in the area law framework and demonstrates its natural alignment with an isothermal description of black hole composition. We discuss the Zeroth law compatibility of the fractional entropy and define an empirical temperature for the horizon. We highlight the distinction between the empirical and conventional Hawking temperatures associated with the black holes. Unlike the Hawking temperature, this empirical temperature appears universal, and its proximity to the Planck temperature suggests a possible quantum gravity origin. We also establish the connection between these temperatures. Furthermore, extending the conventional fractional parameter <i>q</i>, constrained between 0 and 1, we establish that any positive real number can bound <i>q</i> under the concavity condition, provided the log of micro-state dimensionality exceeds <span>(q-1)</span>. Specifically, for black holes, <span>(q = 2)</span>, necessitating micro-state dimensionality greater than <i>e</i>, thereby excluding the construction of black hole horizon states with two level bits or qubits. We also identify the connection between the validity of the second law and information fluctuation complexity. The second law requires that the variance of information content remain smaller than the area of the black hole horizon. This constraint naturally gives rise to a Boltzmann–Gibbs-like entropy for the black hole, which, in contrast to the canonical formulation, is associated with its mass rather than its area. Equilibrium distribution analysis uncovers multiple configurations, in which the one satisfying the prerequisites of probability distribution exhibits an exponent stretched form, revealing apparent deviation from the Boltzmann distribution.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"85 4","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-025-14107-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749132","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}