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To improve the dielectric response of capacitive CaCu3Ti4O12/TiO2 ceramics (referred to as CaCu3Ti4.2O12 and abbreviated as Ti02), ceramics were single-doped with either Sr2+ or Mg2+ ions and co-doped with Sr2+ and Mg2+ ions. Systematically, the effects of single- and co-substitution of Sr2+ or Mg2+ and (Sr2+, Mg2+) ions on the dielectric constant (ε′), loss tangent (tanδ) and nonlinear properties of Ti02 fabricated by a polymer pyrolysis solution method were investigated. X-ray diffraction analysis showed the cubic perovskite crystalline phase of all prepared ceramics identified within the space group Im-3. It was found that the grain size of Ti02 decreased substantially with (Sr2+, Mg2+) co-doping. Additionally, (Sr2+, Mg2+) co-doped Ti02 had higher dielectric thermal stability than either Sr2+ or Mg2+-doped Ti02. Moreover, the co-doped Ti02 revealed a large dielectric response over extended ranges of frequency and temperature, as demonstrated by its outstanding ε′ value of ∼ 4 × 104 from 102–105 Hz and 20–210 °C, respectively. A very high breakdown field (Eb) value of ∼ 2579.25 V.cm−1 with a non-linear coefficient (α) of ∼ 10.01 and a minimal tanδ value of ∼ 0.033 were achieved in a co-doped MgSr05-1 ceramic. The noticeable increase in grain boundary resistance (Rgb) due to a decreased mean grain size and improved potential barrier heights (ΦB) in all doped Ti02 were responsible for the reduced tanδ and superior dielectric thermal stability.

The use of geopolymer in place of ordinary Portland cement for concrete design and constructure is gaining attraction due to environmental and health considerations. Geopolymers must have high gamma radiation shielding competence in order for them to be useful for radiation shielding concrete. In an attempt to improve the gamma absorption capacity of a metakaolin-based geopolymer matrix, 10 % (GEO-10Y), and 20 % (G-20Y) yttria (Y2O3) was mixed with GEO through a solid-state reaction process. In this study, the influence of adding yttria on the physical and gamma shielding parameters of GEO was investigated. The densities of GEO, GEO-10Y and GEO-20Y were obtained as 2.28, 2.52 and 2.37 g/cm3, respectively. Through simulation using FLUKA code, the mass attenuation coefficients (MAC) and other relevant shielding quantities were estimated. The MACs of GEO, GEO-10Y, and GEO-20Y were within the range of 0.0213–6.6429 cm2/g, 0.0282–13.3923 cm2/g, and 0.0291–14.5136 cm2/g, respectively. The addition of yttria improved the gamma photon shielding competence of the metakaolin-based geopolymer by increasing the MAC and reducing photon buildup factors within 15 keV–15 MeV photon energy range. The shielding effectiveness of the yttria-doped GEO compares well with conventional shielding materials. Yttria-doped geopolymer can be used to produce effective and environmentally-friendly gamma shielding concrete.

We theoretically investigate Goos-Hänchen effect for electron in single-layered semiconductor microstructure (SLSM) modulated by Rashba spin–orbit coupling (SOC). Due to the SOC effect, GH displacement is obviously dependent on spins, which allows electron spins to be separated in space dimension and results in spin polarization of electrons in semiconductors. Spin polarization ratio is associated with incident energy, incident direction and in-plane wave vector, e.g., it reaches maximum at resonance, but no spin polarization effect appears at normal incidence. In particular, both magnitude and sign of spin polarization ratio are controlled by external electric field or semiconductor-layer thickness, therefore, a manipulable spatial electron-spin splitter is obtained for semiconductor spintronics device applications.

This study explores the complex dynamics of magnetohydrodynamic (MHD) Casson fluid in a non-uniform rough channel, focusing on the effects of temperature-dependent viscosity and variable thermal conductivity under no-slip boundary conditions. The study employs an innovative approach by utilising a rough surface with irregular textures to analyse flow patterns and assess drag forces on channel objects. A novel mathematical model, governed by continuity, momentum, and heat transfer equations, is developed and transformed into dimensionless, nonlinear Ordinary Differential Equations (ODEs) using non-dimensional quantities and fundamental assumptions. The Optimal Homotopy Analysis Method (OHAM) is applied to solve these equations to enhance convergence speed and accuracy. The research explores the impact of surface roughness on velocity profiles and temperature distributions under various physical constraints. Numerical simulations are conducted to determine skin friction coefficients and Nusselt numbers. Furthermore, the study examines the influence of confined boluses on fluid flow in diverse physiological conditions. A comprehensive analysis is performed to elucidate the combined effects of surface roughness on fluid passage, including flow separation, pattern alterations, pressure distribution and drop, heat transfer characteristics, and flow resistance. The intricate interplay between temperature-dependent viscosity, varying thermal conductivity, and surface roughness is thoroughly investigated to explain the complex dynamics of MHD Casson fluid movement in non-uniform channels. Implementing a magnetic field over the rough, non-uniform channel is found to provide stability and prevent fluid overflow. This research has significant real-world applications, including soil erosion prevention, blood flow regulation in arteries, and optimisation of hydropower channels and penstocks. By enhancing our understanding of flow dynamics through rough and non-uniform channels, this study contributes valuable insights into both theoretical fluid mechanics and practical engineering applications.

Dual-frequency excitation of dielectric barrier discharge (DBD) plasma reactors, where the plasma is generated by a low-frequency (LF) source and modulated by a radio-frequency (RF) source, have been widely adopted in the low-pressure regime. However, the impacts of the RF voltage and LF voltage amplitudes on the plasma parameters, including the spatiotemporal distributions of ion and electron densities, electron dynamics, and gas temperatures, remain poorly understood in the atmospheric pressure regime. The present work addresses this issue by conducting joint experimental and simulation studies for an atmospheric-pressure 50 kHz/5 MHz dual-frequency driven DBD plasma reactor based on phase-resolved optical emission spectra and a drift–diffusion model. The results demonstrate that the dynamic spatiotemporal behaviors of electrons change dramatically as the voltage of the RF component increases from 50 V to 300 V with the voltage of the LF component fixed at 1 kV. Moreover, the RF component is further demonstrated to modulate other plasma characteristics, such as particle densities, gas temperature, and argon emissions. These results contribute toward the tailoring of the non-equilibrium and nonlinear plasma parameters obtained under atmospheric pressure conditions.

This study presents an analysis of an AlGaN/GaN high-electron-mobility transistor (HEMT) with a triple-trench structure (TT-HEMT) for the enhancement of breakdown voltage, which is often limited by the high electric field near the gate edge. Using COMSOL Multiphysics, simulations were run, with trenches made of gallium nitride (GaN) constructed between the GaN and aluminum nitride (AlN) nucleation layers. Each trench was positioned directly beneath the source, gate, and drain contacts. Under the metal gate, a p-type doped GaN cap is added to produce an enhancement mode device, which is more desirable in high-power applications. The results indicate that the effective dispersion of the electric field distribution enhances the breakdown voltage of the device by 70 % in comparison to a conventional HEMT. Additionally, the impact of various design parameters, such as the p-GaN doping concentration and the metal gate work function on the electrical performance, was also investigated. Overall, the proposed device structure exhibits superior electrical properties for high-power applications.

We explain the reasons why a simple approximate expression for the interaction energy between two parallel uniformly charged wires works so well for the calculation of the stored electrostatic energy of a uniformly charged square and/or rectangular plate. The expression under consideration was also found to be very accurate when calculating the total energy of a model consisting of an arbitrary number of uniformly charged wires placed parallel to each other along a one-dimensional regular lattice when the number of wires is not very small. One can use the derived approximate expression for the interaction energy instead of the more elaborate exact one in all circumstances where there is no need for an extremely high accuracy.

This study investigates the intermolecular interactions between 6-mercaptopurine (MP) and 6-thioguanine (TG) drugs with Fe- and Ni-layered single hydroxides (LSH) using DFT calculations. Hydrogenated Fe and Ni LSH show the best performance as drug agents with suitable adsorption energies and moderate interactions with the drugs. Computational analyses, including Natural Bond Orbital (NBO), Non-Covalent Interaction (NCI) surfaces, optical properties, and electronic structure evaluations, elucidate the impact of drug loading on these materials. NCI surface analyses reveal strong attractive interactions within LSH carriers, crucial for their stability, while weaker van der Waals interactions with MP/TG drugs suggest the potential for controlled drug release. Optical and electronic property shifts underscore notable optical and electronic changes upon drug loading, essential for detecting the adsorption process. These characteristics demonstrate LSH’s robustness and effectiveness in designing effective drug delivery systems.

The dynamics of the Rosen–Zener transition (RZT) in interacting two-level systems within nonreciprocal systems is examined, where nonreciprocity stems from asymmetric couplings between energy levels. For the linear case, an analytical expression for the RZT probability is derived. In the nonlinear scenario, numerical experiments are utilized to investigate the impact of various initial states and scanning periods on transition probabilities under adiabatic conditions. Additionally, an equivalent classical Hamiltonian is formulated to elucidate the origin of transition asymmetry under different initial state conditions. The influence of energy level detuning on the RZT is explored, leading to the suggestion of new applications for studying parameters of two-level systems related to nonlinearity and nonreciprocity. This opens avenues for potential Rosen–Zener–Stückelberg interferometry implementations.

The diffusion behaviour of the Ti–Ag system was investigated using classical molecular dynamics by simulating a diffusion couple at various temperatures. One bulk of the diffusion couple consisted of titanium atoms arranged in a hexagonal close-packed (hcp) structure, i.e., α-Ti, and the other consisted of silver atoms arranged in a face-centred cubic (fcc) structure. The modern second nearest-neighbour modified embedded-atom method (2NN-MEAM) interatomic potential was used. The mean square displacement (MSD) of Ti atoms diffusing into Ag and Ag atoms into α-Ti was recorded during the simulation. Diffusion coefficients were determined from the slopes of lines fit to linear regions of MSD dependence on time. The Arrhenius relation was used to determine the activation energy and the frequency of attempts. The activation energy of Ti was 0.61eV and frequency of attempts 1.90⋅10−8m2s−1. The determined activation energy of Ag and frequency of attempts were not considered reliable because the Ag diffusion coefficient did not grow exponentially with temperature. Ti atoms penetrated deeper and greater amounts into Ag than Ag into α-Ti and also had a greater diffusion coefficient at all temperatures. The results were compared with the available experimental data, and for these purposes, self-diffusion in α-Ti and Ag was further investigated. Finally, it was determined that Ag diffuses in α-Ti by hopping over interstitial positions and Ti in Ag via vacancies.

In this article, a time-varying coefficient modified nonlinear Schrödinger equation (tvcmNLSE) with non-zero boundary conditions (NZBCs) at infinity, phase term of which contains time-varying coefficients, is proposed to describe the nonlinear propagation behavior of optical pulses in non-uniform optical fibre. Meanwhile, the Riemann–Hilbert method (RHM) for the tvcmNLSE with NZBCs is presented for the first time. Specifically, a special transformation is constructed to convert the tvcmNLSE with NZBCs into the case with constant NZBCs, and the associated asymptotic spectral problem (ASP) is obtained. By introducing a suitable two-piece Riemann surface to map the original spectral parameter into a single-valued one, and analyzing the ASP, we construct the corresponding Jost solutions and spectral matrix, and sequentially analyze their analytical, symmetric, and asymptotic properties. Then, a generalized Riemann–Hilbert problem (RHP) is established that relates to the converted tvcmNLSE with constant NZBCs. Using the reconstruction formula, we further derive N-soliton solution with NZBCs in the absence of reflection potential, and analyze the dynamic characteristics of single and double solitons. Most notably, by modulating discrete spectral points (DSPs) and time-varying coefficients, we discover some previously unreported new waveforms, such as parabolic and periodic solitons with NZBCs. These waveforms have important implications in both theory and practice. In addition, the influences of different time-varying coefficients, NZBCs, and DSPs on soliton solutions are also discussed and analyzed. This study shows that the selection of time-varying coefficients, distribution of DSPs, and constraints from NZBCs all have significant impacts on the properties of soliton solutions.

Electrically pumped random lasing based on Pd/SiO2/ZnO nanorods (NRs) structures is demonstrated. Chemical bath deposition (CBD) technique was used to synthesize the ZnO NRs. Then, an insulating layer of SiO2 was deposited via radio frequency (RF) magnetron sputtering. After that, direct current (DC) magnetron sputtering was used to deposit palladium (Pd) metal contacts on the sample through a shadow mask. The electrical, morphological as well as optical characteristics of the ZnO NRs were analyzed. The device exhibits typical Schottky diode current–voltage (I-V) characteristics at a turn-on voltage of 6.18 V. The electroluminescence (EL) spectra shows good random lasing behavior with lasing peaks centered at approximately 380 nm and exhibited a threshold current of 37.5 mA. This report reveals Pd as a relatively cheaper material and low-cost CBD fabrication method is sufficient to fabricate electrically pumped random laser devices. Furthermore, this report also present a new way to interpret the mechanism of random lasing in the device.

In this paper, we study the edge effects on the electronic transmission of chiral silicene nanoribbons (CSiNRs) using the tight binding method and Green’s function approach. The investigation covers SiNRs of different chiralities and widths under the influence of transverse and vertical electric fields. The results show significant variations in the electronic properties of SiNRs based on these parameters. The study further explores the role of edge states in the electronic properties of CSiNRs, a topic of recent interest due to potential applications for efficient transport of electrical or optical signals. The results contribute to the understanding of the anisotropic nature of electronic transport in silicene ribbons and open new avenues for the exploration of silicene-based electronic and optoelectronic devices.

This study focuses on the Scale-Invariant (SIdV) families of third-order equations, which are among the few known equations sharing the same solitary wave solution of the KdV equation in the form of sech2. The primary objective is to generalize existing or discover new third-order KdV–SIdV families that feature the analytical sech2 solution of the KdV equation. The study aims to identify all admissible advecting velocity functions ensuring that the KdV–SIdV families accommodate every asymptotically decaying KdV traveling wave with the same wave speed, independent of the advecting velocity. Furthermore, the investigation seeks to delineate their corresponding conserved properties, thereby enhancing our understanding of these intriguing nonlinear partial differential equations. It is shown that the discovered KdV–SIdV families, while sharing the same solitary wave solution, exhibit differing conservation properties. Additionally, a qualitative analysis is conducted using phase plane trajectories to examine the traveling wave solutions and their characteristics for a particular SIdV equation. The emphasis lies in comprehensively exploring potential bifurcations and phase portraits of the vector fields governed by the corresponding system in the parametric space. Through the analysis of distinct phase trajectories across various regions, we derive a new diverse range of solitonic wave solutions, including bell/anti-bell solitary waves, peakon waves, singular waves, and periodic singular waves.

The application of limited polarization and gain control to the recently demonstrated mode-locked ultralong ultrafast, EDFA-based and Raman-assisted pulsed ring fibre lasers is shown to reduce output pulse duration and noise, as well as to increase pulse peak power in cavities of 10 km with repetition rates as low as 38 kHz and pulse durations below 200 fs FWHM, which remain effectively depolarized at the output in the optimized case, accompanied by improved mode-locking stability. The impact of polarization state optimization prior to the doped-fibre amplification section on these devices is studied for different lengths of fibre, harmonic modes, and Raman amplification values. Peak power is nearly doubled thanks to temporal compression and spectral broadening, with a wide choice of regimes of operation dynamically available for a given cavity length, allowing the modification of laser output towards targeted pulse characteristics.

Vanadium dioxide (VO2) has become a reliable phase change material (PCM) and is increasingly utilized in multifunctional metasurface design. This study introduces designs of bilayer anisotropic VO2 meta-atoms in simulation for multifunctional wavefront modulation in the terahertz band. By leveraging the phase change property of VO2 and incident wave polarization, a reconfigurable metasurface composing anisotropic meta-atoms is proposed with four distinct functions. When VO2 is in its insulating state, the metasurface serves as a hologram generator for the x-polarized wave and a focusing reflector for the y-polarized wave. Upon the transition of VO2 into the metallic state, the metasurface functions as a generator of vortex beam for the x-polarized wave, while as an anomalous reflector for the y-polarized wave. The proposed metasurface showcases an outstanding broadband performance, delivering impressive four-channel wavefront modulation within a frequency range of 2.2–3.0 THz. Depending on the compact structure and integrated multi-functionalities, our design may have immense potential across a wide range of terahertz applications, including communication exchange and multiplexing utilization.

Non-Hermitian systems based on anti-parity-time (PT) symmetry reveal rich physics beyond the Hermitian regime. Here, the anti-PT-symmetric photonic lattice is effectively achieved in a four-level inverted Y-type 85Rb atomic vapor. Such instantaneously reconfigurable anti-PT-symmetric photonic lattice possessing susceptibility of χ(x)=−χ∗(−x), is established by a one-dimensional standing-wave coupling field under the assist of a standing-wave driving field. The input probe beam experiences a periodic refractive index modulation when traveling through the photonic lattice, the evolution of output diffraction patterns with symmetric, asymmetric, and lopsided intensity distribution is obtained by adjusting the relevant parameters of constructed non-Hermitian system. Moreover, the anti-PT symmetry in two-dimensional case of both square and hexagonal lattices are correspondingly realized. Our work promotes the development of non-Hermitian devices, and also has some important applications in quantum simulation.

We study the entanglement of two interacting electric dipolar molecules in graphene in a thermal reservoir measured by Wootters’ Concurrence. The entanglements of the two qubits’ initial Bell basis and Werner state are both kept in several seconds and then decrease to zero.

Using the field-theory approach combining bosonization and renormalization group, we investigate the weak-coupling phase diagram of the unconventional Hubbard chain, where in addition to a bond–charge interaction (X), the Hubbard interaction differs between odd (Uo) and even (Ue) sites. The result shows that at quarter filling, the unequal Hubbard repulsion has a great influence on low-energy charge excitations. For the attractive X, the umklapp scattering always exists, and the ground state only exhibits a spin-gapless insulating phase with dominant spin-density-wave correlations. For the repulsive X, the umklapp processes only take place if both Uo and Ue are greater than 8Xcos(π/4), and the phase diagram consists of three phases, a metallic phase with the spin-gapped singlet superconducting correlation, and two insulating phases characterized by the spin-density-wave and charge-density-wave correlations. We also present the phase diagram of the standard t-U-X chain in the case of non-half filling.

In the context of quantum information, a quantum battery refers to a system composed of quantum particles that can store and release energy in a way that is governed by the principles of quantum mechanics. The study of open quantum batteries is motivated by the fact that real-world quantum systems are almost never perfectly isolated from their environment. One important challenge in the study of open quantum batteries is to develop theoretical models that accurately capture the complex interactions between the battery and its environment. The goal of studying open quantum batteries is to develop practical methods for building and operating quantum devices that can store and release energy with high efficiency and reliability, even in the presence of environmental noise and other sources of decoherence. In this study, we will investigate the impact of the classical driving field on the charging and discharging processes of open quantum batteries. The application of a classical driving field can effectively regulate the charging and discharging processes of a battery, resulting in enhanced performance and increased efficiency. It will also be demonstrated that the efficiency of open quantum batteries is influenced by the detuning between the qubit and the classical driving field, as well as by the detuning between the central frequency of the cavity and the classical driving field.

The possibility of the breaking of Lorentz symmetry has been discussed in many models of quantum gravity. In this paper we follow the Lorentz violation model in Ref. [14] (i.e., our previous work) to discuss the Doppler frequency shift of photons and the Compton scattering process between photons and electrons, pointing out that following the idea in Ref. [14] we have to modify the usual quantum relation of photons in the Doppler effect. But due to the current limited information and knowledge, we could not yet determine the specific expression for the correction coefficient in the modified quantum relation of photons. However, the phenomenon called spontaneous radiation in a cyclotron maser give us an opportunity to see what the expression for this correction coefficient might look like. Therefor, under some necessary constraints, we construct a very concise expression for this correction coefficient through the discussion of different cases. And then we use this expression to analyze the wavelength of radiation in the cyclotron maser, which tends to a limited value at v → c, rather than to 0 as predicted by the Lorentz model. And the inverse Compton scattering phenomenon is also discussed and we find that there is a limit to the maximum energy that can be obtained by photons in the collision between extremely relativistic particles and low-energy photons, which conclusion is also very different from that obtained from the Lorentz model, in which the energy that can be obtained by the photon tends to be infinite as the velocity of particle is close to c. This paper still follows the purpose in Ref. [14] that the energy and momentum of particles (i.e., any particles, including photons) cannot be infinite, otherwise it will make some physical scenarios invalid. When the parameter Q characterizing the degree of deviation from the Lorentz model is equal to 0, all the results and conclusions in this paper will return to the case as in the Lorentz model, so this paper also provides us with a possible experimental scheme to determine the value of Q in Ref. [14], although it still requires extremely high experimental energy.

Magnetic properties of 2- and 6-line ferrihydrite (2LFh and 6LFh, respectively) as well as 2-line ferrihydrite embedded in SiO2 (2LFh/SiO2) in the temperature range 2–380 K are investigated using DC magnetization and AC magnetic susceptibility measurements. All the samples exhibit superparamagnetic (SPM) responses at temperatures above their respective blocking temperatures in the range TB = 36–50 K. Linear extrapolations of 1/χ’ vs. T at 80 Hz and high temperatures give effective magnetic moment per atom μeff = 5.78 μB for 2LFh, μeff = 6.27 μB for 2LLFh/SiO2 and μeff = 5.20 μB for 6LFh using Curie-Weiss law. The Arrhenius plots give anisotropy constants K = 4.5 × 105 J/m3 for 2LFh, K = 5.5 × 105 J/m3 and K = 1.5 × 105 J/m3 for 6LFh using the particles size of 40, 35 and 60 Å derived from TEM data on the same samples. The number of uncompensated moments at the surfaces which contribute to the overall magnetic moments of the particles were estimated from the Néel model for antiferromagnetic nanoparticles and yielded magnetic moment per particle μp ∼ 283 μB, 251μB and 465 μB for 2LFh, 2LFh/SiO2 and 6LFh, respectively. At 10 K, well thin the magnetic regime, the spins are blocked in specific directions resulting in usually large MS which appears to increase with decreasing nanoparticle size. Demagnetization behaviors were used as fingerprint techniques to identify the magnetic ordering and the nature of the interactions within the samples, they confirm the existence of AFM core at temperature below TB superimposed to a ferrimagnetic-like shell (at the surface). IRM/TRM measurements, particularly the TRM characteristic peaks at specific fields ranging from H = 10–40 kOe confirmed the existence of a spin-glass state below TB in the samples.

We present a nanoscale refractive index plasmonic sensor based on Fano resonance. We simulate and numerically analyze a novel double T-shaped resonator structure made of conductor–insulator waveguides. Our simulation results show that two Fano resonance peaks can be achieved by the interference between a broadband mode in the straight waveguide and a narrowband mode in the T-shaped resonator. The shifts of Fano resonance peaks by changing the sample refractive index in the resonator structure facilitates the design of a refractive index sensor. To attain a sensor with high sensitivity and figure of merit we employ different geometrical parameters for the resonator structure and analyze the transmission spectra of the sensor. By optimizing the sensor structural parameters we achieve a maximum sensitivity of 523.5 nm/RIU and figure of merit of 2×105 for the sensor made of metal–insulator waveguide. By employing graphene at the core–cladding boundary of the waveguides we attain a high sensitivity of 662.3 nm/RIU and figure of merit of 6.6×105 compared to the literature. We employ samples with refractive indices ranging from 1.0 to 1.05 to analyze the sensor capabilities and employ blood plasma samples to analyze the applications of our sensor structure as a biosensor. Simple fabrication, compactness and high sensitivity are the main advantages of the proposed sensor structure.

This paper investigates the pure-cubic complex Ginzburg–Landau equation (PC-CGLE) with different nonlinearities such as Kerr law, power law and so on. We get the dynamic systems and show that solitons and periodic solutions exist through the complete discrimination system for the polynomial method (CDSPM). To verify these conclusions, we construct the traveling wave solution via the CDSPM, and some new solutions are also built. The soliton stability and modulation instability with two types of nonlinearities are discussed. Finally, by adding perturbed terms to the dynamic system, we obtain the largest Lyapunov exponents and the phase diagrams of the equation, which proves there are chaotic behaviors in PC-CGLE. The results such as Gaussian soliton solutions and chaotic behavior for PC-CGLE are initially discovered in the present paper.

In this study, we investigate the longitudinal wave equation (LWE) with the M−fractional derivative, which describes the propagation of longitudinal waves along a rod while incorporating interactions between mechanical, electrical, and magnetic fields within the material. Initially, we apply bifurcation analysis to examine the critical points or phase portraits where the system transitions to new behaviors, such as stability shifts or the emergence of chaos, and observe the mechanism of static soliton formation through a saddle-node bifurcation. Subsequently, we utilize a modified simple equation (MSE) technique to find solitary wave solutions. Depending on the relationships between free parameters, the solutions are expressed as hyperbolic, trigonometric, and exponential functions. The numerical form of the obtained solutions reveals complex phenomena, including dark and bright bell waves, kink periodic lump waves, kink periodic waves, periodic lump waves, interaction waves between kink and periodic waves, linked lump waves, and interactions of periodic and lump waves. Additionally, we compare our results with previously published work, demonstrating that the discussed methods are valuable tools for providing distinct, accurate soliton solutions relevant to nonlinear science and technology applications.

The purpose of this work is to present an analytical method that allows to estimate in an approximate and fast way the presence of the non-resonant and ultra-fast multipactor effect in RF accelerating structures in the presence of high gradient electromagnetic fields. This single-surface multipactor regime, which has been little studied in the scientific literature, is characterised by appearing only under conditions of very strong RF electric fields (of the order of tens or hundreds of MV/m), where it is predominant over other types of single- or dual-surface resonance described in classical multipactor theory. This type of multipactor causes a rapid growth of the electron population and poses a serious drawback in the operation of RF accelerator components operating under high gradient conditions. Specifically, in dielectric-assist accelerating structures (DAA) it has been experimentally found that the presence of multipactor limits the maximum operating gradient of these components due to a significant increase in the reflected power due to the discharge, being this phenomenon the main problem to overcome. In a previous work, we found and described in detail by means of numerical simulations the presence of this non-resonant and ultra-fast multipactor regime in a DAA structure design for hadrontherapy. Here we aim to present a simple and fast method to predict the presence of this non-resonant and ultra-fast multipactor regime in RF accelerator structures with cylindrical revolution symmetry around the acceleration axis. This method is especially useful in the design stages of accelerating structures as it provides much faster results than numerical simulations of the multipactor, with quite good accuracy in a wide range of cases as shown in this paper.

Polyvinyl alcohol (PVA) and carboxymethyl cellulose (CMC) have been used as polymeric matrices to create polymeric nanocomposite films that contain polypyrrole (PPY) and melanin as fillers. The structure of the PVA/CMC/PPy/x wt % melanin blends was analyzed using the X-ray diffraction technique. The scanning electron microscopy technique was used to investigate the morphologies of the blends. The highest absorbance and reflectance spectra were observed when the melanin content reached 0.25 and 0.2 % wt %, respectively. The smallest direct and indirect optical band gaps are (4.91, 4.44) eV and (4.22, 3.79, 2.34) eV, respectively, achieved when the melanin content was 0.25 wt%. The blend doped with 0.15 wt% PANi yielded the highest refractive index values (1.396 at λ = 600 nm). The optical dielectric constant values of the blends exhibited irregular improvement when the PVA/CMC/PPy blended polymer was filled with varying quantities of melanin. The blend doped with 0.15 wt% melanin exhibits the highest optical conductivity values in the visible range. The blend of PVA/CMC/PPy with a melanin concentration of 0.15 or 0.2 wt% demonstrated the highest nonlinear optical parameters. The blend of PVA/CMC/PPy with a melanin concentration of 0.15 or 0.2 wt% demonstrated the highest nonlinear optical parameter. Based on the observed behavior of the I-V characteristic, the possibility of ohmic conduct ions or space charge limited conduct ions is ruled out in all blends. The charge transport mechanisms that take place in different blends under varying temperatures were examined. These outcomes suggest the opportunity of employing the created blended polymer in capacitive energy storage, optoelectronic devices and photocatalytic application.

We discuss the stability of topological quantum droplets with the shape of two-dimensional soliton rings endowed with angular momentum that stem from a symmetric binary mixture in a Bose–Einstein condensate, with a strong trapping in one of the three spatial dimensions. We show that, in the lossless symmetric case, modeled by a Schrödinger equation with a Shannon-type nonlinear potential function, stable eigenstates can exist for arbitrarily large values of their topological charge l, provided the number of atoms is above a certain threshold. By comprehensive numerical computations, we analyze in detail cases up to l=50. We have found the perturbation modes and their eigenvalues, determining in each case which one dominates and destabilizes the solutions that lie below the stability threshold. We compare these results to the fate of the eigenstates that evolve in time. We also study the stability of the droplets under dynamical conditions by simulating collisions with potential barriers.

We study the steady-state non-Hermitian magnomechanical system driven by a transverse magnetic field directly interacting with YIG sphere yielding in magnons excitation, which later interacts with cavity microwave photons. To make the system non-Hermitian, we use a traveling field directly interacting with magnons generating gain to the system. We start by illustrating PT-configuration of the system containing two PT broken regions around exceptional point and PT protected region along the axis of exceptional point. We discover that the steady-state population of cavity photons and magnons show bistable behavior depending upon the PT configuration, which becomes more significant as the values of the magnon–photon coupling and traveling field strength increases. We illustrate that steady-state photon only shows bistable behavior when the system in lossy PT broken configuration, means strength of traveling field is less than the magnon–photon coupling. Otherwise, it will just contain a single stable state because of bistability suppression with gain in the system, which is unlike with any other investigation in this direction. Further, a larger magnon–photon coupling increases photon intensity and decreases magnon intensity, because of photon and magnon energy exchange, leading to enhanced photon bistablity and decreased magnon bistability. However, in case of increasing strength of traveling field, both photon as well as magnon bistability is appeared to be decreasing. We also study the steady-state effective potential of the system and illustrate the occurrence of bistability with nonlinear interactions between contour trajectories, which similarly depends on the PT broken configuration of the system.

In this manuscript, we introduce a totally asymmetric simple exclusion process on a dynamic lattice with inhomogeneity to model motor-based long-range transport along microtubules (MTs) which exhibit cycles of growth, shortening and regrowth at their growing tips. By mean-field approximation and numerical simulations, we explore phase diagrams for the particle density near the dynamic end of the lattice as well as over the entire lattice. In particular, we find seven different phases for the density over the entire lattice and explore the corresponding phase diagram by analytical analysis. Interestingly, we find that the density may have a linear profile in part of the lattice. When the lattice has a defect, we separate the lattice into two subsystems: a right subsystem with fixed length and a defect in the middle and a left subsystem with dynamic length. When the right subsystem is in maximum-current phase, we calculate an analytical approximation of the density away from the boundaries and the defect site and the density is in association with the reduced hopping rate at the defect site; the density at the left side of the defect site serves as the effective entry rate of the left subsystem. We find that with defects, the linear profiles no longer appear at the left end of the left subsystem and only five possible phases could occur. This is a step-forward to a more comprehensive mathematical description of intracellular long-range transport of organelles along MTs with instability.

Quantum Cellular Automata (QCA) technology offers promising prospects for designing molecular electronic circuits that operate at high frequencies and with ultra-low power consumption. QCA wires serve as crucial conduits for digital data transmission between logic gates. A series of QCA cells arranged sequentially forms these wires, with data written or read using paired nanogap electrodes. In this study, employing a simplified full-basis quantum mechanical model, we investigate the impact of single and double missing cells on the response function and output voltage of wires implemented within the two-dot QCA architecture. The electronic coupling between the quantum dots within each QCA cell stands out as a critical structural parameter influencing both the nonlinearity of the response function and the level of output voltage. Ground state analyses of wires affected by missing-cell defects suggest that employing QCA cells with weak electronic coupling could potentially enhance fault tolerance. However, examination of excited states reveals that reducing electronic coupling may compromise the thermal robustness of such defective QCA wires.

In this study, we investigated the size- and shape-dependent optical nonlinearity of silver nanoparticles (AgNPs), and their modulation upon mixing with 2D ZnO nanoflakes (ZnONFs) using a Z-scan technique powered by a continuous-wave 514.5 nm Ar-ion laser source. We prepared three batches of AgNPs with varying average particle sizes of 36 nm, 64 nm, and 81 nm and one batch of ZnONFs, by employing chemical reduction and hydrothermal preparation protocols, respectively. Our experimental results revealed a decrease in the values of the nonlinear refractive index of AgNPs with an increase in their average sizes. It appeared that variation in the shape of the AgNPs does not have any appreciable impact on the optical nonlinearity. The value of the nonlinear refractive index of AgNPs amplified significantly upon mixing with ZnONFs. Interestingly, the magnitude of the enhancement of the nonlinear refractive index of AgNPs was found to be dependent on the proportion of both ZnONFs and AgNPs in the mixture. We could harvest ∼ 4 times larger magnitude of the nonlinear refractive index of AgNPs, by mixing 40 % of AgNPs with the lowest average particle size with 60 % of ZnONFs.

Quantum discord goes beyond entanglement and exists in a wide range of quantum states that may be separable, playing a crucial role in quantum information tasks. In this paper, we firstly proposed a zero-discord criterion for two-qubit system based on the partial transposition of density matrix, and then extended it to the qubit–qudit system. By detailed examples we demonstrate the effectiveness of these criteria in detecting discord. Moreover, we provide an analytical lower bound of geometric quantum discord(GQD) using eigenvalue vectors of density matrix. Finally, we presented a one-way work deficit lower bound based on our lower bound of GQD.

This paper investigates the relation between the Berry phase of a spinor accumulated along a path corresponding to an adiabatically varying magnetic field and the conformal deformation along the path in the parameter space. The first part demonstrates that the accumulated phase can be controlled by continuous deformation characterized by a single conformal parameter. The source of the corresponding field strength responsible for the deformed phase path is shown to be a conformally deformed monopole located at the origin in the parameter space with the fundamental strength g=±1/2. In the second part, we model a rotating magnetic field coupled to a charged spinor with a time-varying amplitude subjected to the conformal deformation, realizing a single-variable deformation of the evolution process of the phase path.

A natural non– Hermitian system is constructed based on 85Rb atoms and multi-dressing fields. On this basis, the influence of different dressing fields on symmetry breaking and energy level degeneracy during four-photon spontaneous eight-wave mixing based on seventh-order nonlinear effects is investigated, and four-photon correlations are analyzed. When the dressing Rabi frequency dominates, the real part splits, leading to in phase constructive dressing, its symmetry breaking is localized, non-degenerate, Abelian and has low symmetry. When the dephase rate dominates, the imaginary part splits, leading to out-of-phase destructive dressing, its symmetry breaking is nonlocal, degenerate, non– Abelian and highly symmetric. The interactions between the dressing fields and the eigenvalue splitting modes of two double dressing effects that have third-order EPs are compared, and the role of the internal and external dressing fields in the formation of third-order EPs is clarified. The third-order non-Hermitian interaction between two dressing fields of the nested scheme is strongest and weakest for the parallel scheme, with the cascade scheme intermediate between them. This study is of value for the detection and quantum storage of quantum states.

In this paper the electromagnetic (EM) field expressions for a magnetic pendulum are derived. The mechanical frequency and the magnetic dipole moment are found by applying mechanical-kinetic theory. A study of the expressions reveals that the electromagnetic field contains both the fundamental and higher order harmonic waves, which is quite different from a magnet with simple harmonic motion, and their amplitude ratios are governed by Bessel Functions of the first kind. 1 Hz radiator system is used for the experimental verification. The radiation pattern, the efficiency and the Q factor of the pendulum are discussed in detail. This paper provide the theoretical basis with the experimental verification of the pendulum antenna.

We report the experimental observation of soliton molecules in a dispersion-managed thulium-doped (Tm-doped) fiber laser utilizing a black phosphorus saturable absorber (BP-SA). A variety of soliton molecules can be detected with the increase of pump power and the adjustment of cavity polarization state. Additionally, we use numerical simulation to investigate the soliton dynamics and further explore soliton molecules with variable and controllable properties. Stable separation-changeable soliton molecule has been numerically observed through changing small signal gain G in the cavity. These results enhance research into multi-soliton complexes as well as its practical application.

Nonreciprocal transmission, reflection and absorption are very important in quantum science. For their realization, cavity magnonics is attracting much attention, where Kittel mode describing collective excitations of a large number of spins is excited through driving magnons with a strong microwave field. The cavity photons and magnons are coupled via magnetic dipole interaction, while the magnons and phonons are coupled via magnetostrictive interaction. By applying experimental feasible parameters, we breaks the symmetry of spatial inversion in order to realize nonreciprocal transmission, reflection absorption. Our results reveal a new strategy to protect quantum resources for building noise-tolerant quantum processors, realizing chiral networks, and invisible quantum sensing.

In this paper, the Zn0.95Cu0.05O/p-Si heterojunction with lateral photovoltaic effect (LPE) is prepared that has the tuning effect and switching behavior of sunlight field. The dependence of the lateral photovoltage (LPV) on the laser position shows high sensitivity (20 mV mm−1) and strict linearity. Interestingly, the LPV eventually decreased to 0 mV as the sunlight intensity increased to 48 mW, under the constant laser intensity and position, indicating the application potential of a photo-switch. This light field effect results from the irradiation of sunlight, which changes the position of quasi-Fermi level, reduces the drive power for carriers by the space charge region in the heterojunction, and increases the concentration of carriers resulting in increased the scattering between carriers to decrease the lifetime of carriers produced by the laser. This work can expand the application of LPE in the field of multifunctional devices such as photo-switches, position sensors and self-powered devices.

We research the mutual correlation and chaotic behavior in phantom Anti-de Sitter (AdS) black holes based mainly on shock wave geometry. In the static background of the phantom spacetime, by analyzing mutual correlation, we find out that the greater the phantom dark energy parameter is, the smaller the mutual correlation becomes, which implies phantom dark energy can destroy bilateral correlation of the two sub-regions from the AdS boundary. In the dynamic background, the results show that, the greater the applied energy perturbation is, the smaller the mutual correlation becomes. Especially, the bigger the phantom dark energy is exerted, the faster the mutual correlation destroys. This is similar to the butterfly effect of chaos theory.

This research investigates the characteristics and attributes of a new (3+ 1)-dimensional Boussinesq equation that describes shallow water waves in higher dimensions. By utilizing the Hirota bilinear representation, a bilinear Bäcklund transformation is provided for the proposed model to get soliton solutions. Then, the extended transform rational function method is applied to calculate the complexitons type solutions. The results demonstrate various exact solutions with different structures, including periodic, singular, and bright solitons. Comprehensive graphical representations in 2D, 3D, and density plots are provided to highlight the physical properties of these solutions. Our approach is distinguished by the unique nature of the problem and the use of previously untested methods in this context, leading to many new and original optical soliton solutions. These results highlight the effectiveness of the proposed method in tackling nonlinear problems in engineering and the natural sciences, exceeding previous work found in the literature.

Unlike other conventional metal chalcogenides, where the Perdew-Burke-Ernzerhof (PBE) functional tends to underestimate band gaps, bismuth (Bi) chalcogenides, particularly Bi selenides, exhibit a counterintuitive behaviour with band gap predictions that closely align with experimental results. In this study, we report this anomaly in the band gap prediction of specific Bi-based chalcogenides. The structures of these compounds are of significant interest because their electronic band gaps match well with the reported experimental results when using the PBE functional. This unexpected and counterintuitive deviation, observed in this class of materials, offers valuable insights for material scientists studying compounds in this category.

Water from the industries contains various organic effluents which are needed to be removed. Photocatalysis is an efficient method to degrade organic effluents that contaminate water and harmfully affect the environment. This study presents the structural, optical characteristics, and photocatalytic activity of the CuO/MoS2 and their composite with gCN. The hydrothermal approach was employed to fabricate MoS2 nanoflowers, and the co-precipitation method to fabricate CuO. The composite with gCN was prepared successfully using an ultrasonication approach. The physio-chemical properties of fabricated photocatalysts were investigated by various characterization techniques. SEM analysis revealed the nanoflower morphology of the prepared MoS2 sample. The photocatalytic activity was examined by the photodegradation of methyl orange dye and phenol. CuO/MoS2@gCN photocatalyst showed 85.14 % degradation of methyl orange and 63.50 % degradation of phenol. Also, the rate constant of CuO/MoS2@gCN was found to be 0.051 min−1 for MO dye and 0.02 min−1 for phenol, which is higher than other synthesized samples. The scavenging experiment was carried out to identify the most photoactive species involved in the organic pollutants photocatalytic degradation. Electrons served as the primary photoactive species in photocatalysis. Consequently, it is concluded from the results that CuO/MoS2@gCN could be employed as an efficient photocatalyst for wastewater treatment.

In this paper, an ultra-thin (0.072λ) composite stealth cloak is proposed to cover a cloak with a center height of 98.88 mm and an inclination angle of 25° to achieve the dual stealth effect of scattering and gain. Firstly, based on the Generalized Snell theorem, the designed anomalous reflective metasurface has been shown to have a good invisibility in the 14–30 GHz region in simulations as well as in experiments. Secondly, the 3-bit metasurface unit is utilized to generate vortex beams with different number of modes, whose electric field strength at the vortex singularity is 0, which achieves energetically stealth. Finally, the phases of the above two metasurfaces are superimposed using the convolution theorem, and the designed composite stealth cloak significantly reduces the scattering amplitude and reconstructs the wavefront over a wide frequency range when a circularly polarized wave is incident vertically. Based on the above study, the stealth cloak provides a feasible solution for application to radar and microwave antenna stealth systems.

Neutron stars are among the main targets for gravitational wave observatories, however, their equation of state is still not well established. Mainly phenomenological models with many parameters are widely used by far, while theoretical models are not so practical. In arXiv:1902.08477, a theoretical equation of state with only one parameter is derived from Witten–Sakai–Sugimoto model, as an application of AdS/QCD, where pointlike instanton case is taken into consideration. When the tidal deformability constraint from gravitational wave event is satisfied, the maximum mass is about 1.7 solar masses. Now we upgrade this model to instanton gas, with one more variable, the instanton width. This is not naively a free parameter, but a function of the chemical potential. Thus we end up with a more complicated and accurate model, but still with only one adjustable parameter. In this case, we find the maximum mass becomes 1.85 solar masses. This is an encouraging result, as a theoretically derived model.

Accurate detection of low-level radioactivity is critical for decommissioning projects in nuclear facilities, particularly in the design of radiation monitoring systems with a low false alarm rate. Utilizing a non-parametric Bayesian continuous probability distribution enables reliable mapping of potential contamination. Our method introduces a statistical test based on a Pólya tree prior, applied to radiation detection. The detection efficiency of this proposed Bayesian test is quantified using receiver-operating characteristic (ROC) curves and compared to a Bayesian test based on the Kibble bivariate gamma distribution developed for the same purpose. The results demonstrate that the new Bayesian test generally outperforms the previous method in terms of detection performance under very low signal-to-noise ratios, with improvements ranging from 3% to 28% against both stationary and non-stationary radiological backgrounds, respectively. This superiority is further reaffirmed through comparisons with alternative Bayesian and frequentist hypothesis tests, with gains estimated at 52% and 4%, respectively.

We analyze the transverse momentum spectra of proton (p), deuteron (d), triton (t), and helium (3He and 4He) in different centrality intervals in various rapidity slices in gold–gold (Au–Au) collisions at sNN=3 GeV. We apply the blast-wave model with Tsallis statistics (TBW) to transverse momentum spectra of the particles, which fits well the data of STAR Collaboration. The freezeout parameters such as kinetic freezeout temperature, transverse flow velocity, and kinetic freezeout volume are extracted. Our findings reveal that central collisions exhibit higher values for the kinetic freezeout temperature, transverse flow velocity, and kinetic freezeout volume (which means that the central collisions are more hot and expansive), and observed that they decrease from central to peripheral collisions, and the former two parameters decrease from backward rapidity regions to mid-rapidity. This indicates a rapid expansion of the system in central collisions and in backward rapidities. The above parameters are mass-dependent, and the former increases, while the latter two decrease for heavier particles, reflecting the multiple kinetic freezeout and volume differential freezeout scenarios. Besides, the entropy parameter (q) is extracted, and it increases from peripheral to central and from backward to mid-rapidity regions.

In this article, we examine the optical soliton solutions of the 4th-order nonlinear Boussinesq water wave equation using the modified (G′/G2)− expansion and F-expansion methods. We utilize the similarity transformation to transform the partial differential form of the equation into an ordinary differential form. These techniques present a variety of solutions, including bright, dark, singular, dark-periodic, and singular-periodic soliton solutions. We plot the derived solutions in several profiles, such as 2D, 3D, and contour, to illustrate their physical appearance. The determined findings might be useful and have an enormous effect on the research of nonlinear phenomena in a variety of physical areas of science, like shallow water waves, acoustics, fluid dynamics, laser optics, communication systems, and heat transfer. The achieved results demonstrate the validity, applicability, and effectiveness of the presented method. We plot and validate the found solutions using the computational program MATHEMATICA.