The European Physical Journal Plus最新文献

{"title":"Thermodynamics and emergent thermomechanical response of a quantum ring with nonminimal spin–orbit coupling","authors":"João A. A. S. Reis,&nbsp;L. Lisboa-Santos,&nbsp;Edilberto O. Silva","doi":"10.1140/epjp/s13360-026-08212-4","DOIUrl":"10.1140/epjp/s13360-026-08212-4","url":null,"abstract":"<div><p>We investigate the thermodynamic and emergent thermomechanical properties of fermions confined to a one-dimensional quantum ring with effective spin–orbit interactions induced by nonminimal couplings to antisymmetric tensor fields. Using the exact spectrum obtained in the companion work, we develop canonical and grand-canonical descriptions and show that the coupling parameter <span>(xi )</span> deforms the angular-momentum branches, reorganizing the low-energy spectrum and leaving clear signatures in the internal energy, entropy, heat capacity, and spin–orbit response functions. We also formulate an effective thermomechanical description by treating the ring circumference as a quasi-static thermodynamic variable. This leads to a pressure-like quantity and associated response coefficients, directly linked to the microscopic spectrum. In the grand-canonical ensemble, Fermi statistics strongly enhance the response, producing coupling-dependent instabilities and sign changes reminiscent of mesoscopic de Haas–van Alphen oscillations. Finally, we introduce a phenomenological interacting extension based on an exponential resummation of the free energy, showing that collective effects can sharpen the thermomechanical response and induce anomalous thermal contraction. Our results connect spectral deformation, finite-size thermodynamics, and emergent mechanical behavior in spin–orbit-active quantum rings.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjp/s13360-026-08212-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148859836","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":"Coexistence of phonon-mediated superconductivity and nontrivial band topology in rock-salt Scandium pnictides ScX (X = As, Sb, Bi)","authors":"A. Elbahri,&nbsp;M. Ragragui,&nbsp;L. B. Drissi,&nbsp;E. H. Saidi","doi":"10.1140/epjp/s13360-026-08169-4","DOIUrl":"10.1140/epjp/s13360-026-08169-4","url":null,"abstract":"<div><p>Quantum materials with coexisting superconducting and topological properties are highly promising for future technological applications. In this work, we investigate the Scandium pnictides ScX <span>((X = As, Sb, Bi))</span> in the rock-salt structure, using density functional theory calculations combined with Wannier-based tight-binding models. The optimized structures exhibit robust dynamical stability, as confirmed by their phonon dispersion curves. Electron–phonon coupling calculations combined with isotropic Eliashberg theory predict conventional phonon-mediated superconductivity in all three compounds. Electronic structure calculations (GGA, <span>(GGA+SOC)</span>, HSE) indicate semimetallic behavior with partial band gaps that evolve under spin–orbit coupling. Notably, SOC drives ScSb and ScBi toward a topologically nontrivial electronic phase, where gap reduction leads to Dirac-like surface states and nonzero <span>(mathbb {Z}_2)</span> invariants. Surface projections on the (100), (101), and (111) planes highlight distinct topological features across the ScX compounds. Our results demonstrate the coexistence of conventional phonon-mediated superconductivity and a topologically nontrivial normal state in ScSb and ScBi, thereby identifying these compounds as promising platforms for future investigations of the interplay between superconductivity and nontrivial electronic topology.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 8","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148838389","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":"High-z galaxies with the JWST and the ELT: toward ever-finer detail","authors":"Eros Vanzella","doi":"10.1140/epjp/s13360-026-08201-7","DOIUrl":"10.1140/epjp/s13360-026-08201-7","url":null,"abstract":"<div><p>The exploration of the early Universe is being transformed by the <i>James Webb Space Telescope</i> (<i>JWST</i>), which delivers unprecedented angular resolution at infrared wavelengths and opens a unique window redward of the <i>K</i> band (2 µm). Thanks to <i>NIRCam</i>, <i>NIRISS</i>, <i>NIRSpec</i>, and <i>MIRI</i> instruments, which provide both imaging and spectroscopy with exquisite efficiency, new classes of sources have emerged within the first years of operations. The first half-Gyr of cosmic time is now routinely probed, revealing massive blue/red galaxies and a population of Active Galactic Nuclei (AGN) appearing as “little red dots” together with a rest-frame near-infrared/optical view of sources across the reionization and post-reionization epochs. Angular resolution will remain pivotal in the 2030–2040s, when extreme adaptive optics (AO) facilities will be deployed on both (8–10) m (e.g., the VLT Multi-Conjugate Adaptive Optics (MCAO)-Assisted Visible Imager and Spectrograph, <i>MAVIS</i>) and on extremely large telescopes, like the 39 m ELT (e.g., Multi-conjugate adaptive Optics Relay For ELT Observation, <i>MORFEO</i>). Operating at the diffraction limit, these facilities will improve JWST s resolution, with ELT achieving a factor of <span>(simeq 6)</span> smaller Point-Spread-Function (PSF). An ELT diffraction-limited PSF (with a Full Width Half Maximum, FWHM <span>(approx)</span> 8–12 mas) in the near infrared will resolve spatial scales <span>(&lt;100)</span> pc at any redshift (z <span>(lesssim 18)</span>), revealing abundant star-forming clumps with sufficient sensitivity. Leveraging gravitational lensing as a cosmic telescope, even with moderate magnification factors (µ<span>(sim)</span>4–8), diffraction-limited 8 m and 39 m telescopes will probe physical scales <span>(lesssim 25)</span> pc, enabling systematic studies of star formation down to star cluster scale at cosmological distances. Such observations are poised to become routine in the 2030–2040s.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 8","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjp/s13360-026-08201-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148838230","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":"Robust topological edge states in flexible valley-Hall photonic crystals","authors":"Qi Kang,&nbsp;Lili Dai,&nbsp;Li Wei,&nbsp;Weiwen Li","doi":"10.1140/epjp/s13360-026-08220-4","DOIUrl":"10.1140/epjp/s13360-026-08220-4","url":null,"abstract":"<div><p>A novel design for valley-Hall photonic crystals (VHPCs) is achieved by interfacing two distinct photonic crystal structures with similar band structures. Topologically protected edge states are demonstrated at the interface between triangular star and triangular petal photonic crystals, exhibiting strong confinement to the <i>K</i> and <i>K</i>^′ valley with negligible intervalley scattering. The robust edge transport confirms the topological nature of the designed VHPCs. This approach provides enhanced flexibility in structural design while maintaining topological protection, making it suitable for photonic applications such as waveguides and sensors.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 8","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148838390","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":"Performance of CaF2:Tm and CaSO4:Dy dosimeters for entrance surface dose and mean glandular dose in mammography: a phantom study","authors":"Engin Aşlar,&nbsp;Vural Emir Kafadar","doi":"10.1140/epjp/s13360-026-08216-0","DOIUrl":"10.1140/epjp/s13360-026-08216-0","url":null,"abstract":"<div><p>In this study, the dosimetric performance of CaF₂:Tm (TLD-300) and CaSO₄:Dy (TLD-900) dosimeters was evaluated in mammography using breast phantoms with various breast thicknesses (2–6 cm) and glandularity fractions (30–70%). The dosimeters exhibited good repeatability and linear dose–response characteristics within the air kerma range of 3.3–16.1 mGy. Entrance surface dose (ESD) and mean glandular dose (MGD) were determined across all phantom configurations as a function of phantom thickness and tissue composition. Accordingly, ESD and MGD varied 1.07–22.93 mGy and 0.46–3.19 mGy, respectively. The MGD values rose by up to 60% across glandular fractions (30–70%), while increasing phantom thickness from 2 to 6 cm resulted in an approximately three to fivefold increase, with all values remaining below internationally recommended reference levels. Overall, the close agreement (within experimental uncertainties) between the results obtained with TLD-300 and TLD-900 demonstrates that both dosimeters are suitable and comparable alternatives for ESD and MGD estimation in mammography dosimetry.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 8","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148838215","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":"Thermodynamics and orbital structure of anti-de Sitter black holes in Palatini-inspired nonlinear electrodynamics","authors":"Edilberto O. Silva,&nbsp;João A. A. S. Reis,&nbsp;Faizuddin Ahmed","doi":"10.1140/epjp/s13360-026-08172-9","DOIUrl":"10.1140/epjp/s13360-026-08172-9","url":null,"abstract":"<div><p>We construct a consistent anti-de Sitter completion of the static and spherically symmetric black-hole solution sourced by the Palatini-inspired nonlinear electrodynamics <span>(Y^n)</span> model. Here, “Palatini-inspired” denotes exclusively a first-order formulation of the electromagnetic sector, in which the gauge potential and an auxiliary antisymmetric tensor are varied independently; the gravitational sector is the standard metric Einstein–Hilbert theory with the Levi-Civita connection. Starting from the Einstein–Hilbert action with a negative cosmological constant and the first-order PINLED sector, we derive the full set of field equations and show that the nonlinear electromagnetic solution preserves its original parametric structure, while the lapse function acquires the standard AdS contribution. We then analyze the horizon structure, Hawking temperature, extended phase-space thermodynamics, and the associated equation of state. In addition, we investigate null and timelike geodesics, with emphasis on the effective potentials, photon sphere, critical-curve (shadow boundary) radius for a static observer at finite distance, and innermost stable circular orbit. The resulting framework furnishes the exact AdS extension of the asymptotically flat PINLED black hole and provides a coherent basis for numerical and phenomenological studies of its thermodynamic, optical, and orbital properties.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 8","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjp/s13360-026-08172-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148838216","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":"A new two-dimensional chaotic signal over GF(p)","authors":"Jiawei Yu,&nbsp;Sanshuai Cui","doi":"10.1140/epjp/s13360-026-08160-z","DOIUrl":"10.1140/epjp/s13360-026-08160-z","url":null,"abstract":"<div><p>To resist the degradation of chaotic systems, this paper explores a new two-dimensional chaotic signal based on the known chaotic system over GF(<i>p</i>). First, we select a chaotic system within the range of integers. Then, we adopt nonlinear coupling with the variables of the system to generate new chaotic signals. Finally, we test the obtained chaotic signals using indicators such as bifurcation diagrams, phase diagrams, Lyapunov exponents, entropy, and NIST. Through experiments, it is known that our method has good chaotic characteristics and randomness. Compared with traditional methods, our approach does not require mathematical formula derivation, is simple and easy to implement, and offers a new idea for generating chaotic signals within the integer domain.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 8","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148838346","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":"Neutral-current neutrino–nucleus scattering off 127I and 133Cs: Coherent and incoherent contributions with electroweak refinements for odd-A nuclei","authors":"Muhammad Farooq,&nbsp;Shakeel Mahmood,&nbsp;Muhammad Faisal Khan","doi":"10.1140/epjp/s13360-026-08156-9","DOIUrl":"10.1140/epjp/s13360-026-08156-9","url":null,"abstract":"<div><p>Calculations of neutral-current neutrino–nucleus scattering cross sections are essential for interpreting low-to-intermediate energy data, yet terrestrial measurements remain limited. The COHERENT Collaboration’s 2017 observation of coherent elastic neutrino–nucleus scattering (CEνNS) on CsI[Na] at the Spallation Neutron Source reported 134 ± 22 (stat) ± 30 (syst) events, corresponding to ~ 77% of the Standard Model central prediction (173 ± 48), consistent within uncertainties but leaving room for improved theoretical modeling. Motivated by this, we compute neutral-current cross sections for ¹²⁷I and ¹³³Cs within a unified and self-consistent analytical framework that includes coherent elastic, incoherent excitation, and spin-dependent axial contributions for these odd-A nuclei, with a consistent distinction between nuclear and nucleon form factors. The incoherent component is treated following standard structure–function-based approaches, ensuring a physically motivated decomposition of the total cross section. Electroweak effects are incorporated through momentum-transfer-dependent <span>({text{sin}}^{2}{theta}_{W})</span> (MS scheme) and flavor-dependent neutrino charge radius corrections, consistently implemented in the vector couplings. Cross sections are presented as functions of neutrino energy and for decay-at-rest spectra, within the low-to-intermediate energy regime where elastic and quasi-elastic processes dominate. Inclusion of incoherent and axial terms enhances the total cross section by factors of <span>(sim 2)</span> at <span>({E}_{nu }approx 10 text{M}text{e}text{V})</span> (<span>(sigma approx 2 times {10}^{-42}{text{cm}}^{2})</span> versus pure CEνNS <span>(sim {10}^{-42}{text{cm}}^{2})</span>) and leads to incoherent dominance at <span>({E}_{nu } approx 50 MeV)</span> (<span>(sigma approx {10}^{-40}{text{cm}}^{2})</span>). Expected interaction rates for DAR neutrinos reach <span>(sim 0.1 text{e}text{v}text{e}text{n}text{t}text{s}/text{k}text{g}/text{y}text{r})</span> near a <span>(40 text{k}text{e}text{V})</span> recoil threshold. The results are benchmarked against CEνNS expectations and show qualitative consistency with COHERENT observations, while providing a systematic assessment of subleading contributions relevant for CsI-based detectors and astrophysical applications.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 8","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148838191","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":"Spherically symmetric quintessential black holes in antisymmetric tensor gravity","authors":"Ahmad Al-Badawi,&nbsp;Faizuddin Ahmed,&nbsp;İzzet Sakallı","doi":"10.1140/epjp/s13360-026-08189-0","DOIUrl":"10.1140/epjp/s13360-026-08189-0","url":null,"abstract":"<div><p>We present a theoretical investigation of black hole solutions in Kalb–Ramond gravity embedded with quintessence-like field. Our study examines how combined effects of Lorentz violation through the Kalb–Ramond field parameter and exotic matter contributions via quintessence parameters systematically modify spacetime geometry, particle dynamics, and observational signatures compared to standard Schwarzschild black holes. The analysis encompasses geodesic motion for both photons and massive particles, revealing modifications to effective potentials and photon-sphere characteristics, and showing that stable circular orbits form a finite ring that exists only below a threshold quintessential intensity. We derive the shadow angular radius for a static observer at finite distance, with the distant-observer limit available only for <span>(w=-1/3)</span>, and show that all three quintessence states studied admit real, well-defined shadows once the physical photon-sphere branch is selected. Our perturbation analysis of scalar and electromagnetic fields shows how Lorentz violation and quintessence effects alter wave propagation and stability properties. Using the Gauss–Bonnet theorem in its finite-distance formulation, we evaluate the gravitational deflection angle exactly for source and receiver inside the static patch. The thermodynamic investigation is built on the Wald entropy, which acquires a constant Lorentz-violating factor, and yields an exact first law together with corrected free energy and heat capacity on the event-horizon branch. Across all sectors examined, the two deformation parameters act in opposite directions on the effective potentials, orbit radii, shadow size, and thermal quantities, and the corrected expressions delimit the parameter domain on which these statements hold.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 8","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148838218","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":"Phase transition for a black hole with matter fields and the relation with the Lyapunov exponent","authors":"Pakhlavon Yovkochev,&nbsp;Bobomurat J. Ahmedov,&nbsp;Bum-Hoon Lee,&nbsp;Hocheol Lee,&nbsp;Wonwoo Lee","doi":"10.1140/epjp/s13360-026-08210-6","DOIUrl":"10.1140/epjp/s13360-026-08210-6","url":null,"abstract":"<div><p>We construct static black hole solutions coexisting with anisotropic matter in asymptotically (anti-)de Sitter spacetime and investigate how the matter field modifies their thermodynamic and dynamical properties. The anisotropic matter generates an exponentially decaying charge-like contribution to the metric, causing the geometry to interpolate between the Schwarzschild black hole in anti-de Sitter spacetime and the Reissner–Nordström black hole in anti-de Sitter spacetime. In anti-de Sitter black hole spacetime, we derive the complete thermodynamic description, including the Hawking temperature, heat capacity, Smarr relation, generalized first law, and Helmholtz free energy. The system exhibits a van der Waals-type small/large black hole phase transition with a critical point determined by the matter field parameters. Local thermodynamic stability is characterized by the heat capacity, whereas global stability is determined through the free energy. We further investigate unstable homoclinic orbits by evaluating the Lyapunov exponent associated with null geodesics. Our analysis reveals that different thermodynamic branches possess distinct dynamical instabilities, and that the thermodynamically preferred phase is accompanied by a smaller Lyapunov exponent. These results demonstrate that thermodynamic stability and geodesic instability are correlated because both originate from the same underlying spacetime geometry.</p></div>","PeriodicalId":792,"journal":{"name":"The European Physical Journal Plus","volume":"141 8","pages":""},"PeriodicalIF":2.9,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148838179","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}