This paper investigates the validity of KNO scaling in UrQMD-simulated proton-proton (pp) collisions at root s = 2.76 TeV, 7 TeV and 13 TeV. The analysed data points are found to lie approximately on the universal curve psi(z) = Azexp(-Bz) with A = 4.61 +/- 0.12 and B = 2.19 +/- 0.07. The obtained simulation results have been compared with the experimental measurements reported by the ALICE and the CMS Collaborations, demonstrating good consistency and providing an insight into the energy dependence of particle production in high-energy pp collisions. Copyright (c) 2026 EPLA All rights, including for text and data mining, AI training, and similar technologies, are reserved.
The characterization of topological phases in disordered non-Hermitian systems remains a formidable challenge, as the non-Hermitian skin effect (NHSE) disrupts the conventional bulk-boundary correspondence and renders spectral invariants unreliable. In this letter, we propose the real part of the biorthogonal entanglement entropy as a precise, basis-independent diagnostic that cuts through this complexity. Investigating a disordered non-reciprocal Kitaev chain, we demonstrate that this entropic probe provides a robust, boundary-sensitive diagnostic that faithfully tracks the topological phase transition even in regimes where traditional winding numbers fluctuate wildly. Crucially, we uncover an anomalous critical scaling of the entanglement entropy: while the Hermitian limit follows standard conformal scaling (ceff approximate to 1.69), the non-Hermitian critical point exhibits a super-critical effective central charge of ceff approximate to 2.81. Within the studied system sizes (L <= 600), this enhancement is consistent with skin-effect-driven non-unitary behavior at the critical point. Our findings establish biorthogonal entanglement not only as a robust order parameter for the topological Anderson insulator but also as an experimentally accessible signature in topo-electric circuits. Copyright (c) 2026 EPLA All rights, including for text and data mining, AI training, and similar technologies, are reserved.
In this paper, anisotropic Bianchi type-III spatial homogeneity and Kantowski-Sachs cosmological model have been explored in the presence of the f(R, T) theory. In this we have sorted the proper curvature vector field by Riemann tensor of rank 6 & times; 6 in the f(R,T) gravity theory for Bianchi type-III and Kantowski-Sachs models with some algebraic operations and the process of direct integration. Classification of the mentioned spacetimes leads to seven cases based on a different function f(R, T) and their values. On analyzing all such instances, we find out that seven cases are possible. Among these cases, five admit non-trivial curvature collineations (CCs) which are vector space over an infinite dimensional field. For the other two examples, there are no proper CCs and the Killing vector fields (KVFs) are these homothetic vector fields (HVFs); this kind of HVFs becomes KVFs.
study the influence of the Aharonov-Bohm quantum phase on a quantum system described by a non-Hermitian Hamiltonian. We show that a non-Hermitian Hamiltonian has real energy eigenvalues which are influenced by the Aharonov-Bohm quantum phase. In addition, we show that persistent currents can arise. Finally, we calculate the revival times in this twodimensional system and show that they are influenced by Aharonov-Bohm quantum phase. Copyright c 2026 EPLA All rights, including for text and data mining, AI training, and similar technologies, are reserved.
This work explores a heuristic connection between modified black holes and the generalized uncertainty principle (GUP). Revisiting Bekenstein's analysis of a particle governed by the GUP and captured by a black hole with undetermined parameters, we find a class of modified Schwarzschild black holes that saturate the Bekenstein-Hawking entropy to the maximum extent. Although curvature singularities cannot yet be definitely ruled out, the modified black holes avoid complete evaporation and end up as zero-temperature remnants. The Hayward black hole is the simplest case, even though it is not the only choice. Copyright c 2026 EPLA
this paper, we extend Plebanski's mapping to encode the Einstein equations in Arnowitt-Deser-Misner (ADM) form within a bianisotropic electromagnetic medium. We realise this by translating the ADM constraints and evolution equations into dynamical conditions on the medium's constitutive parameters. These transformed equations are then linearised in vacuum to derive gravitational-wave analogues as perturbations of the optical medium.
We investigate the interplay between transport phenomena and quantum entanglement, focusing on the entanglement negativity EN, in noninteracting electronic systems. Our study considers a non-Hermitian two-dimensional (2D) stacked Su-Schrieffer-Heeger (SSH) lattice with nonreciprocal hopping amplitudes and balanced on-site gain and loss. We analyze how nonhermiticity, topology, and open-boundary conditions jointly shape the system's transport behavior and entanglement structure. In particular, we investigate how the phase boundary separating the purely real and real line-gapped phases influences the transport coefficients and the entanglement negativity. We analyze the behavior of both the electrical conductivity and EN at zero and finite temperatures. Furthermore, we examine the dependence of the Drude weight DS, which characterizes DC transport in the system, on the entanglement negativity, finding only a slight dependence of the conductivity on EN. Overall, our results highlight the tunability of electrical transport in non-Hermitian systems, providing insights for engineered quantum devices and novel topological materials where gain, loss, and non-hermiticity are intrinsic.
Acoustic metalenses with switchable and high-efficiency focusing are pivotal for advanced manipulation of underwater sound waves. This study introduces a hybrid metalens comprising a central metasurface and a peripheral metagrating. The central metasurface ensures precise focusing at small deflection angles, while the intelligently designed metagrating units, each comprising two elliptic iron cylinders, enable efficient and switchable focusing at large angles. Initially, the metasurface and metagrating operate synergistically to focus normally incident waves into a single transmission side spot with exceptional efficiency and energy confinement, achieving a peak intensity 137 times that of the incident wave and a full width at half-maximum (FWHM) of 0.33). Upon rotating the elliptic cylinders, the hybrid metalens generates two distinct foci: one on the transmission side from the metasurface and another on the reflection side from the metagrating, thereby realizing switchable dual focusing. This compact, high-performance design holds great promise for applications in medical ultrasound, underwater detection, and acoustic communication.
Carbon is one of the most fundamental elements in nature hosting comprehensive allotropes, the understanding of carbon is one of the central topics in condensed-matter physics and materials sciences. In this work, we report by ab initio calculations a systematic investigation on an all-sp(3) hybridized carbon allotrope. This carbon structure has a body-centered cubic unit cell in Ia3 symmetry (T-h(7), space group No. 206) with 64 carbon atoms, which can be discovered through a graph theoretic structural search method originally identified by Shi et al. (Phys. Rev. B, 97 (2018) 014104), and we term it as BC64 carbon in the present work. The dynamical stability of BC64 carbon has been confirmed with phonon band spectrum calculations and its thermal stability up to 1000 K has been confirmed with ab initio molecular-dynamics (AIMD) simulations. It is shown that BC64 is a superhard carbon allotrope with a large Vickers hardness of about 84.5 GPa. The electronic band structures calculations show that BC64 carbon is an insulator with an indirect band gap of about 4.52 eV. Remarkably, the simulated x-ray diffraction pattern of BC64 carbon matches well the experimental data derived from the chimney soot. Previously this experiment is mainly explained by a series of all-sp2 hybridized carbon allotropes such as bco-C16 and bct-C16, and only one all-sp(3) hybridized sc-C46 is proposed to explain this experiment; however, BC64 shows a better match with this experiment comparing with sc-C46 carbon. Our work has provided systematical understanding of a superhard all-sp3 hybridized carbon allotrope, and also provided a reasonable explanation for previous experimental data, which will also supply guidance for future theoretical and experimental studies in related fields. Copyright (C) 2026 EPLA
lies at the core of numerous quantum information processing applications. A main obstacle against implementing powerful quantum information tasks is decoherence that degrades, or even destroys, entanglement. Therefore, developing strategies to mitigate decoherence is essential for practical implementations. Here, we propose a scheme to enhance exciton-exciton entanglement in an exciton-optomechanical cavity incorporating a Kerr medium. Under experimentally feasible conditions, we demonstrate that the Kerr nonlinearity not only strengthens excitonic entanglement, but also allows it to persist over a wide range of operating parameters. While strong exciton-phonon coupling is required for entangling the two excitonic modes in the Kerr medium-free case, we show that such coupling is no longer necessary when the Kerr interaction is introduced. Remarkably, the presence of the Kerr medium enables the excitonic entanglement to survive up to room temperature without requiring a very high mechanical quality factor. Our scheme provides a promising route for generating robust entanglement and may open new possibilities for quantum information applications.
With the rapid development of complex networks, their effective control has attracted widespread attention. To ensure controllability, it is necessary not only to identify driver nodes but also to determine an exact input matrix. In this paper, a method based on path cover is proposed to derive an exact input matrix that satisfies the Kalman rank condition for complex networks. By assigning sufficiently large edge strength to each path in the cover, the network becomes controllable through this input matrix. The method is applicable to complex networks that are directed or undirected, weighted or unweighted. For directed networks, controllability is ensured by controlling only the source nodes of each path. In contrast, for undirected networks, it suffices to control either the source or endpoint nodes within each identified path cover. Consequently, the resulting input matrix is simple and practical for implementation.
Elastic wave mode conversion is a fundamental mechanism in wave manipulation. A key challenge is to achieve efficient longitudinal-to-transverse mode conversion at low frequencies. In this work, we numerically demonstrate that a pair of coiling-up structures embedded in a solid medium can induce nearly complete mode conversion at extremely low frequencies, where the wavelength is more than 50 times the structural period. Parametric studies and modeling reveal that the outermost opening of the coiling-up structure plays a dominant role in determining the conversion frequency. This structural detail has been largely overlooked in previous studies. A simplified Helmholtz resonator model is introduced to explain the observed effect. The proposed design offers a geometrically induced resonant yet structurally compact approach for low-frequency elastic wave control. Copyright c 2026 EPLA
The area law emerges in quantum (d + 1)-dimensional systems such as zero-temperature critical phenomena as well as black holes (and related cosmological models). For wide classes of systems, it can be expressed as the following anomalous scaling of the Boltzmann-Gibbs-von Neumann entropy: S-BG(L) alpha Ld-1-1/ d-1 (L -> infinity; d >= 1) (i.e., S-BG(L) alpha ln L if d = 1 and S-BG(L) alpha Ld-1 if d > 1), instead of the expected standard scaling S-BG(L) alpha L-d, where L characterizes the (dimensionless) linear size of the system which is focused on. Since, for such class of complex systems, the entropy SBG is nonextensive, the Legendre structure of thermodynamics is violated, in contrast with nonadditive entropic functionals such as S-q with specific q < 1 and S-delta with specific delta > 1 which yield extensive entropies, being thus consistent with classical thermodynamics. We discuss here the corresponding canonical and microcanonical thermostatistics and argue that, generically, q(microcanonical )< q(canonical) < 1 and delta(microcanonical) > delta(canonical )> 1, in contrast with the BG theory which naturally yields q(microcanonical) = q(canonical) = delta(microcanonical) = delta(canonical )= 1. Copyright (c) 2026 EPLA All rights, including for text and data mining, Al training, and similar technologies, are reserved.
molecular properties of the semi-aliphatic polyimide derivative with incorporating bulky hydrogen side groups (3H-DC) in solvents are studied theoretically. The optimal reaction path can be found to regulate an excited state intramolecular proton transfer (ESIPT) reaction. The strength of the hydrogen bond increases significantly, and contributes to the ESIPT reaction providing the driving force. From the rearrangement of charge, electron density distribution is also an extremely important positive factor in the ESIPT process. The potential barrier sizes in different solvents are compared, basing on which we present the increase of solvent polarity which promotes the occurrence of the ESIPT reaction for 3H-DC fluorophore. Copyright c 2026 EPLA All rights, including for text and data mining, AI training, and similar technologies, are reserved.
This study investigates the use of global control strategies to enhance the directed migration of swarms of interacting self-propelled particles confined in a channel. Uncontrolled dynamics naturally leads to wall accumulation, clogging, and band formation due to the interplay between self-organization, volume exclusion and confinement. This work explores whether a uniform global control, such as a magnetic field acting identically on all particles, can robustly enhance collective transport. Using a discrete Vicsek-like model, it is found that simple global alignment controls emerging from reinforcement learning, efficiently suppress unfavorable configurations and significantly increase the net particle flux along a prescribed channel direction. These results highlight that coarse, system-level observations are sufficient to achieve global manoeuvring by indirectly reshaping self-organized microscopic dynamics, even in regimes with strong fluctuations or partial ordering.
We propose a mechanism for a spontaneous spin Josephson diode effect (JDE) without an external magnetic field, based on an unconventional p-wave magnet (UPM) with spin-orbit coupling (SOC). In this S/N/UPM/N/S Josephson junction, the UPM provides an intrinsic equal-spin triplet pairing channel, while the interfacial SOC breaks spatial inversion symmetry, endowing Cooper pairs of different spin components with opposite phase gradients. Under zero external magnetic field while time-reversal symmetry is preserved, the charge Josephson diode effect vanishes, whereas the spin rectification efficiency can reach the theoretical limit (100%) for ideal parameters -corresponding to a perfect spin rectification where the spin supercurrent in one direction is allowed, but it is blocked in the other direction. Our results propose a new strategy for achieving highly efficient spin JDE, endowing Josephson-junction-based quantum devices with new functionalities. Copyright c 2026 EPLA All rights, including for text and data mining, AI training, and similar technologies, are reserved.
study of spins and particles on graphs has broad applications, from the dynamics of interacting systems on networks to combinatorial problems. Here, we study the large-n limit of the O(n) model on graphs, which is considerably more challenging than on regular lattices, as the loss of translational invariance gives rise to an infinite set of saddle point constraints in the thermodynamic limit. We show that the free energy at low and high temperature T is determined by the spectrum of two fundamental graph-theoretic objects: the Laplacian matrix at low T and the Adjacency matrix at high T. Their interplay is studied across several classes of graphs. For regular lattices the two coincide. We obtain an exact solution on trees, where the Lagrange multipliers interestingly depend solely on the number of nearest neighbors. We further contrast these classical results with those for a quantum spin model on an exemplary tree. For decorated lattices, the singular part of the free energy is governed by the Laplacian spectrum, whereas this is true for the full free energy only in the zero-temperature limit. Finally, we discuss a bipartite fully connected graph to highlight the importance of a finite coordination number in these results. open access Copyright c 2026 The author(s) Published by the EPLA under the terms of the Creative Commons Attribution 4.0 International License (CC BY). Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.
In this paper, a comprehensive analytical study of the time-fractional generalized Hunter-Saxton model is presented using a separation of variables approach. The model governs the propagation of orientation waves in massive nematic liquid crystals and exhibits intrinsic links to Einstein-Weyl geometric structures. Incorporating a fractional-order time derivative introduces temporal nonlocality, capturing memory-driven effects in the evolution of nonlinear reorientation fronts. An exact reduction to the traveling-wave frame yields closed-form families of solutions representing smooth, kink-type, and singular fronts that propagate at constant speed. For generic parameter regimes, algebraic profiles arise, while a resonant limit produces a smooth exponential front. The analysis further confirms the absence of real periodic traveling waves. Visualization of the exact solutions through three-dimensional surface, contour, and density plots reveals the influence of the fractional order on wave steepening, front morphology, and propagation dynamics, offering theoretical insights relevant to experimental exploration of reorientation phenomena in complex liquid-crystalline media.
investigate a non-supersymmetric mechanism for baryogenesis driven by the nonlinear dynamics of a complex scalar field Phi with a self-interaction term that explicitly breaks the global U(1) symmetry. This self-interaction leads to dynamical generation of asymmetry associated with the U(1) sector in the primordial Universe. The coupled nonlinear dynamical equations governing the real and imaginary components of Phi, evolving in an expanding radiation-dominated background, induce different trajectories for the scalar charge components. Our numerical computation reveals that the resulting Noether charge density decays as rho(t) similar to t-3/2 at late times. Since the photon density in a radiation-dominated Universe also scales as m gamma(t) similar to t-3/2, the Noether charge-to-photon ratio eta(t) = rho(t)/m gamma(t) asymptotically approaches a constant in the long-time limit, t -> infinity. We find that this asymmetry mechanism can operate across different scales, with lower masses requiring weaker interactions and higher masses demanding stronger couplings for the scalar field. Copyright c 2026 EPLA All rights, including for text and data mining, AI training, and similar technologies, are reserved.
search to understand and reduce plasma instabilities in magnetically confined fusion devices has driven the development of increasingly complex nonlinear dynamical models. This paper utilizes the Kosambi-Cartan-Chern (KCC) theory to transform the quasi-periodic plasma perturbations (QPP) model into a second-order differential equation (SODE), and characterise its geometric structure with five KCC invariants. Despite their stability as determined by Lyapunov's first method, the two non-trivial equilibria of the model are Jacobi unstable. The geometric instability shows that the system's trajectories are structurally sensitive, providing a previously unknown complement to the classical understanding of plasma stability. By offering a geometric explanation for the emergence of Jacobi instability, this work bridges a critical gap in plasma stability theory. Hence, the KCC theory is an essential tool for future stability analysis in plasma physics. Copyright c 2026 EPLA All rights, including for text and data mining, AI training, and similar technologies, are reserved.
