物理最新文献

The interaction of energetic ions with semiconductor heterojunctions can significantly influence interfacial states and charge transport, thereby impacting device performance and long-term reliability. In this study, ZnO/p-Si heterojunctions were irradiated with 120 MeV Ag⁸⁺ ions at fluences ranging from 1 × 10¹¹ to 5 × 10¹² ions·cm⁻², and their current-voltage characteristics were systematically examined. Swift heavy-ion irradiation generated lattice disorder, point defects, and interface traps, which reduced the barrier height from 0.82 eV for the pristine diode to 0.68 eV at 5 × 10¹² ions·cm⁻² and increased the reverse leakage current. At low fluence, transient thermal-spike effects slightly improved junction quality, whereas higher fluences produced defect-dominated transport. Under UV illumination, the irradiated heterostructure showed enhanced photocurrent, but its sensitivity decreased due to the irradiation-induced increase in dark current. These results provide important insights into radiation-driven modifications in oxide/semiconductor heterojunctions and emphasize the need to account for such effects while developing devices for radiation environments.

The dependence of (textrm{f}_{0})(980) production on the final-state charged-particle multiplicity is reported for proton–proton (pp) collisions at the centre-of-mass energy, (sqrt{s}=) 13 TeV. The production of (textrm{f}_{0})(980) is measured with the ALICE detector via the (textrm{f}_0 (980) rightarrow pi ^{+}pi ^{-}) decay channel in a midrapidity region of (|y|<) 0.5. The evolution of the integrated yields and mean transverse momentum of f(_{0})(980) as a function of charged-particle multiplicity measured in pp at (sqrt{s}=) 13 TeV follows the trends observed in pp at (sqrt{s}=) 5.02 TeV and in proton–lead (p–Pb) collisions at (sqrt{s_{textrm{NN}}}=) 5.02 TeV. Particle yield ratios of (textrm{f}_{0})(980) to (pi ^{pm }) and (textrm{K}^{*})(892)(^{0}) are found to decrease with increasing charged-particle multiplicity. These particle ratios are compared with calculations from the canonical statistical thermal model as a function of charged-particle multiplicity. The thermal model calculations provide a better description of the decreasing trend of particle ratios when no strange or antistrange quark composition for f(_{0})(980) is assumed, which suggests that the data do not support significant hidden strangeness in the (textrm{f}_{0} (980)).

This study presents the green synthesis and comprehensive characterization of gold nanoparticles (AuNPs) using aqueous extracts derived from Sorbus aucuparia L. (Rowan berries) harvested in Trabzon province, Türkiye. Initially, 100 g of the dried fruit material were thoroughly washed with deionized water to eliminate dust and surface contaminants and subsequently dried under appropriate conditions. The dried fruits were boiled in 500 mL of deionized water for 60 min to obtain the bioactive extract, which was then filtered using Whatman filter paper. Chloroauric acid trihydrate (HAuCl₄·3H₂O, 99.9%) was used as the gold precursor at three different concentrations: 0.1 mM, 0.2 mM, and 0.3 mM. To each concentration, 0.3 mL or 0.5 mL of the fruit extract was added. The reaction mixtures were prepared by combining the extract and 70 mL of the HAuCl₄ solution and stirred gently to ensure uniform dispersion. Microwave-assisted synthesis was employed using a standard household microwave oven at power levels of 180 W, 360 W, and 600 W, for durations varying between 1 and 15 min. Each experimental condition was repeated in triplicate to ensure reproducibility and statistical reliability. Characterization of the resulting AuNPs was performed using UV–Vis spectroscopy, TEM, FTIR, XRD, and Zetasizer analysis. The optimal synthesis conditions were identified as 0.1 mM HAuCl₄ concentration with 0.3 mL of Sorbus aucuparia L. extract under 360 W microwave irradiation. UV–Vis analysis revealed a distinct surface plasmon resonance (SPR) peak, confirming the successful formation of gold nanoparticles. TEM images showed that the AuNPs were predominantly spherical with a mean particle size of 17.750 ± 3.606 nm, ranging from 10.230 to 28.687 nm. The crystallite size calculated from XRD was approximately 12.38 nm. Dynamic Light Scattering (DLS) analysis demonstrated an average hydrodynamic diameter of 45.25 ± 7.9 nm in aqueous suspension. The zeta potential was measured at − 15.2 ± 7.49 mV, indicating moderate colloidal stability. The polydispersity index (PDI) was found to be 0.581, suggesting a moderately polydisperse system. The produced AuNPs remained stable without significant aggregation or precipitation for a period of 2–3 months when stored under ambient conditions.

We investigate the effects of Hawking radiation on quantum steering and steering asymmetry in a tripartite system embedded in Schwarzschild spacetime. All tripartite steering types were classified, comprising three (1rightarrow 2) and three (2rightarrow 1) steering cases. Through a systematic analysis of all physically relevant scenarios (including accessible and inaccessible modes), we classify three canonical scenarios with one, two and three physically accessible modes. In the scenario of three physically accessible modes, Hawking radiation disrupts quantum steering, with the maximum steering asymmetry during the two-way steering to one-way steering transition precisely demarcating the phase boundary between these regimes. For two physically accessible modes, Hawking radiation exhibits dual behavior: enhancing the steering from Alice and Bob to anti-Charlie under certain parameters while suppressing it under others, while net strengthening other steering types. When considering one physically accessible mode, the Hawking effect of the black hole significantly enhances quantum steering. These findings provide new insights into quantum correlations in curved spacetime and establish observable signatures of Hawking effects in quantum steering phenomena.

A finite formulation of quantum field theory based on a system of differential equations reminiscent of the Callan–Symanzik equations is discussed. This system of equations was previously formulated in the bare language, and we re-derive it in a fully renormalized language. For the latter, within a simple (phi ^4) toy model, it is shown that with a specific choice of renormalization conditions—namely, the on-shell scheme for the renormalized mass—this class of finite renormalization prescriptions is equivalent to the standard renormalization group equation written in the Callan–Symanzik–Ovsyannikov form.

We report on new lifetime measurements of the yrast states (6(^+_1)​ to 12(^+_1)​) of (^{162})Er, performed using the Recoil Distance Doppler-Shift (RDDS) method at the Cologne FN Tandem accelerator. From the extracted lifetimes, B(E2) values were determined to trace the evolution of nuclear collectivity at high spin. At low-to-moderate spins ((I le 8)), the trend of the B(E2) values is described qualitatively by the Confined Beta-Soft (CBS) model, confirming the nucleus’s position in the transitional region between X(5) symmetry and the SU(3) rigid rotor limit. At higher spins ((I ge 10)), a sharp drop in the B(E2) strengths indicates the beginning of backbending, marking a clear breakdown of the purely collective description.

We investigate the nonlinear dynamics of black holes in an Einstein-scalar-Gauss-Bonnet (EsGB) gravity theory where a real scalar field couples to both the Gauss-Bonnet invariant and the Ricci scalar through a higher-order coupling function. Starting from both bald and hairy static solutions, we perform full numerical simulations in Painlevé–Gullstrand-like coordinates to follow the time evolution triggered by localized scalar field pulses. We identify the scalarization threshold of the static solutions and uncover four distinct dynamical channels: stable Schwarzschild black holes resisting scalar growth; spontaneous scalarization of Schwarzschild black holes into stable hairy configurations; transitions between metastable and stable hairy states; and complete descalarization of metastable or weakly perturbed hairy black holes back to the Schwarzschild phase. Energy redistribution is quantified using the Misner–Sharp mass, which reveals horizon mass growth and energy transport. The effective stress-energy tensor violates the null convergence condition during scalarization, indicating regions of negative effective energy that support hair formation. Our results demonstrate that scalarized black holes emerge naturally as nonlinear end states of evolution in EsGB gravity, and they highlight the rich phase-space structure and dynamical behavior beyond general relativity.

This paper studies the impact of bulk viscosity on the feasibility of the cosmological bounce solutions in the framework of F(R) theory. In this perspective, the behavior of an isotropic homogeneous universe with a perfect matter configuration and new formulation of the bulk viscosity coefficient is explored. We select a specific mathematical form of the modified gravity model to see how it affects the dynamics of cosmic evolution. In addition, we analyze various cosmological parameters, exploring the presence of feasible cosmological bounce solutions. A physically acceptable bouncing scenario occurs when the energy density stays positive, pressure becomes negative, and the violation of null and strong energy conditions highlight the important role of bulk viscosity. We also study the cosmographic parameters and their paths in the (r-s) diagnostic framework. Finally, a thermodynamic investigation is carried out to test the generalized second law of thermodynamics and the overall stability of the cosmological model. The results show that F(R) gravity is a realistic and promising alternative to the standard cosmological model, giving deeper understanding of gravitational dynamics and the early evolution of cosmos.

In this work, a massive scalar field theory incorporating Lorentz violation is investigated. The symmetry breaking is introduced via a background traceless antisymmetric tensor. Within the framework of Thermo Field Dynamics (TFD), the effects of space-time compactification are explored, allowing the simultaneous treatment of thermal and finite-size phenomena. The resulting modifications to the energy-momentum tensor and Feynman propagator are analyzed, leading to Lorentz-violating corrections to the Stefan-Boltzmann law and the Casimir effect. This unified approach highlights the interplay between temperature, spatial constraints, and Lorentz-violating backgrounds in shaping the behavior of quantum fields.

We investigate non-perturbative bulk corrections arising from instantons in string theory and M-theory. By deriving non-local curvature corrections of the form ( e^{-gamma R} R_{mu nu } R^{mu nu } ), we demonstrate how these modifications emerge from wrapped brane instantons and their summation over multi-instanton configurations. Utilizing holographic techniques, we establish a direct connection between these non-perturbative effects and large-( N ) gauge theories, identifying the appropriate holographic dual conformal field theory (CFT). We further analyze this connection through resummations in the large-( N ) expansion. Additionally, we study black hole solutions in AdS backgrounds and show that these instanton-induced corrections significantly modify the near-horizon geometry. Finally, we explore the regularization of curvature singularities via these exponential damping terms, providing a natural resolution mechanism in quantum gravity. Our findings underscore the fundamental role of non-perturbative physics in shaping the structure of spacetime and its holographic duals.