International Journal of Modern Physics B

In this paper, we quantitatively study the dynamics of the tripartite entanglement of the three-mode Gaussian state in a cavity-free optomechanical system. After deriving the explicit form of the evolved state matrix covariance, we elucidate in detail the evidence of entanglement monogamy in different mode partitions, based on Coofman–Kundu–Wotters inequalities, using the Gaussian Contangle quantifying bipartite entanglement. Next, we focus on the genuine tripartite entanglement quantified by means of the Residual Gaussian Contangle.

In this paper, we introduce optical normalized spherical Heisenberg total ferromagnetic recursional flux of Heisenberg spherical $ℍ𝕊fs$-particle with electromagnetic microscale in Heisenberg spherical space ${ℍ𝕊}^2$. Hence, we investigate the properties of spherical Heisenberg normalized electromagnetic microscale by ferromagnetic recursional model. Also, we study optical normalized spherical ferromagnetic Heisenberg recursional density with normalized ferromagnetic microscale for spherical Heisenberg $ℍ𝕊fs$-fiber in spherical Heisenberg space ${ℍ𝕊}^2$. Finally, we obtain spherical Heisenberg sonic crystal of spherical Heisenberg $ℍ𝕊fs$-fiber with spherical Heisenberg normalized microscale.

Conservation and storage of energy are important issues for human beings in the 21st century. A significant part of the energy is consumed for space cooling in buildings during summer. Passive cooling systems are used due to their low-power consumption; they, however, have some limitations such as lack of sufficient low temperature for the storage of coolth, in various localities. These problems make passive cooling technologies suitable in limited regions and scenarios. In this work, the inclusions of nanomaterials were examined to accelerate the freezing of phase changing material (PCM), with the applications of fins. The base (PCM) is water and CuO nanoparticles were used in this investigation to upgrade the performance. KKL is used to estimate the properties of CuO–water nanofluids. The finite element method (FEM) was employed to simulate this unsteady process. The outcomes indicate that incorporating CuO nanoparticles into pure PCM speeds up solidification process. The total energy and average temperature profiles decrease as the number of undulations upsurges, while the solid fraction profile rises. Furthermore, for $d_p=40$nm, the uppermost rate of solidification is acquired. Increasing the concentration of CuO can make the freezing time to decrease by about 10.11% and 12.85% when the utilized shape factors are 3 and 5.7, respectively. Using particles with a higher shape factor causes the period to decrease by about 4% and 6.9% when concentration is 0.02 and 0.04, respectively.

The MCrAlY bonding layer alloy was prepared by vacuum melting, and the alloy composition was NiCoCrAlY and NiCoCrAlYHfTa. The high-temperature cyclic oxidation experiment was carried out in air at 1050^∘C until it failed. The results show that Hf and Ta have a significant influence on the oxidation resistance of the alloy. The doped specimens have longer oxidation lifetimes compared to the undoped samples. The study also found that the Hf would diffuse out and combine with O to form HfO₂ in the thermally grown oxide (TGO) layer, which would improve the adhesion and reduce the wrinkles of the oxide layer. Ta in the doped specimens hinders the diffusion of Al and reduces the oxidation rate, while improving the thermal mismatch. Therefore, the specimens doped with both Hf and Ta have the highest oxidation lifetimes, though the oxidation lifetime was 10 times longer than that of the undoped specimens. It is indicated that the doping of Hf and Ta is an important method to improve the oxidation lifetime of thermal barrier coatings (TBCs).

Studies on rogue waves (RWs) over constant and periodic wave background are of contemporary interest in several areas of physics. These RWs arise not only on such backgrounds but also appear on double-periodic wave background. In this paper, we derive RW solutions over a double-periodic wave background of a fifth-order nonlinear Schrödinger equation. We create the double-periodic wave background with elliptic functions (in combinations of cn, sn and dn) as seed solutions in the first iteration of Darboux transformation. We then calculate the growth rate of instability for these double-periodic solutions under different values of elliptic modulus parameter. On the top of these background waves, we generate RWs with the help of second independent solution to the eigenvalue problem. Further, we analyze the differences that occur in the appearance of RWs with reference to the lower-order and higher-order dispersions terms. In addition to the above, we examine the derived solutions in detail for certain system and elliptic modulus parameter values and highlight some interesting features that we obtain from our studies.

The spin-1/2 antiferromagnetic (AFM) Heisenberg model is considered in the mean-field approximation in terms of the spin operators ${Ŝ}_x,{Ŝ}_y$ and ${Ŝ}_z$ in the matrix forms with the introduction of bilinear exchange interaction ($J_{\mu }$), the Dzyaloshinskii–Moriya interaction (DMI) (${\mathrm{\Delta }}_{\mu }$) and external magnetic fields ($H_{\mu }$) into the Hamiltonian in three dimensions. The thermal changes of sublattice magnetizations $M_{\mu }^A$ and $M_{\mu }^B$ are investigated in the isotropic case to identify the critical behaviors displayed by the system. The phase diagrams are illustrated on various planes of system parameters for given coordination numbers $q=3,4$ and 6. In addition, the graphs of the magnetization components in the same directions were drawn against each other and very interesting results were obtained. The model exhibits the ordered phases, i.e., AFM, ferromagnetic (FM), and a phase with random or oscillatory behavior (R). The phase transitions are observed between FM and R phases when for all ${\mathrm{\Delta }}_{\mu }\ne 0.0$, between FM and AFM when ${\mathrm{\Delta }}_{\mu }=0.0$ only and, AFM and R at low temperatures for very small ${\mathrm{\Delta }}_{\mu }$ and $H_{\mu }$ values.

Half-Heusler (HH) phases are among the most extensively studied thermoelectric materials. Bipolar thermal conductivity analysis performed for their sub-group based on rare-earth (R) metals, RNiSb, indicated high mobility ratio in favor of electrons. The result motivated studies of ScNiSb${}_{1-x}$Te_x series in which n-type-doped samples shown higher mobility and significantly improved thermoelectric performance [K. Ciesielski et al., Phys. Rev. Appl.  15, 044047 (2021)]. Recently, Kajikawa attempted alternative interpretation of transport properties in ScNiSb, where multi-parameter fit led to mobility ratio in favor of holes [Y. Kajikawa, Int. J. Mod. Phys. B 2250071 (2022)]. In this work we discuss the details of electrical properties and thermoelectric performance of ScNiSb in the context of structural disorder and the most recent experimental literature on a related chemical system. The paper considers also relevant assumptions regarding band degeneracy and scattering mechanisms for effective mass modeling in ScNiSb. Last, technical difficulties of the model proposed by Kajikawa are addressed. We believe that the provided insight will be useful for understating electrical transport in HH compounds, which can contribute to further improvement of their thermoelectric performance.

By using the first-principles calculations established on density functional theory (DFT), the electronic aspects of the tetrahexcarbon (TH-carbon) monolayer as a two-dimensional carbon allotrope which is a direct bandgap semiconductor have been investigated under variations of buckling parameter ($\sigma =0,2,4,6$) by the PBE-GGA. Also, optical properties of this nanosheet are projected in out-of-plane polarization in buckling variation situations up to $\sigma =6$. Its optic behaviors in the visible light spectrum match its electronic ones. The results propose that the TH-carbon monolayer is an appropriate material for designing optoelectronic devices.

The integrable higher-order Heisenberg spin system with quintic terms in self-consistent potential (HHSQ) is an extension of Heisenberg ferromagnetic equations. In this paper, we calculate the Lax expression of the HHSQ system, then the motioning curves in $(1+1)$ dimension of Heisenberg ferromagnetic equations have been discussed. The Darboux transformation of the HHSQ system is constructed and a set of soliton solutions will be demonstrated by Darboux transformation.

Achieving the potential for plasma particle interactions by modifying the Deutsch potential has been considered in many studies. One very convenient way to do this is to utilize the method as a dielectric function. In this method, by applying different potentials, it tries to provide corrective terms in the initial potential. As a result of using this method, an effective potential function is obtained from which the plasma characteristics including state equation and thermodynamic features can be derived. Because the screening effects between plasma particles are not taken into account by the Deutsch potential and therefore show different results from the real values, in this paper, we have tried to add corrective terms with the help of Hulthen potential and dielectric response function to it. Thus, an effective potential was obtained and then its equation of state was derived consequently. Finally, the results of this modified potential and the equation of state were compared with the results of other works.

Within the context of fractional calculus, we investigate novel mathematical possibilities. In this context, using the fractional dispersion relations for the fractional wave equation, we explore a class of the generalized fractional wave equation numerically. Some important classes of differential equations in the theory of wave studies are Drinfeld–Sokolov–Wilson and Shallow Water equations. In this effort, the natural transform decomposition technique has been implemented to investigate the explicit result of fractional-order coupled schemes of Drinfeld–Sokolov–Wilson and Shallow Water coupled systems. The proposed method is obtained by coupling the Natural transform with the Adomian decomposition process. The current technique significantly works to find the approximate solution without any discretization or constraining parameter assumptions. The obtained numerical and graphical outcomes by the devised technique are compared with the available exact result to verify the convergence of the method. For mathematical calculations, the Mathematica software package is used.

This research highlights the physical significance of nanoparticle in magnetohydrodynamics (MHD) stagnation point flow (SPF) over a stretchable surface with porosity effect and boundary slip phenomenon. The nanoliquid and its advanced thermal activity are shown extra auspicious results when the flow is considered over a permeable (porous) medium. In addition, the nanoparticles of radius size play an important role in the thermal performance of nanofluid. In this work, copper is accounted as a nanoparticle and water as a base fluid. Nanomanufacturing, surface engineering, coatings, nanofabrication and tribology are some of the important and special mechanical characteristics of nanoparticles [D. Guo, G. Xie and J. Luo, J. Phys. D, Appl. Phys.  47, 013001 (2014)]. The flow is electrically conducted in the presence of applied magnetic field. Mixed convection, Joule heating and viscous dissipation effects are accounted in the mathematical modeling. Appropriate similarity variables are used to convert the couple governing system of PDEs into ordinary ones and results are computed through bvp4c via shooting concept. From the obtained results, it is divulged that the velocity field increases against higher estimations of unsteady parameter, while it declines versus larger magnetic parameter and radius of nanoparticles. The engineering interest like skin friction and Nusselt number is mathematically calculated and results are computed in a tabular form, and their obtained outcomes show that the magnitude of skin friction rises against unsteadiness parameter and radius of nanoparticles. This study is an extended work of [Verma et al. Chem. Eng. J. Adv. 12, 100366 (2022)] with some extra flow assumptions like MHD, SPF, Joule heating, heat generation/absorption and viscous dissipation. Obtained results are compared with [Grubka and Bobba J. Heat Transf.  107, 248 (1985)], Verma et al. [Chem. Eng. J. Adv.  12, 100366 (2022)] and [Elbashbeshy and Emam Therm. Sci. 15,  477 (2011)] found 100% accuracy with them. The most important result of the conducted study is that the skin friction coefficient immensely augments subject to larger estimations of radius of nanoparticles when permeability of porosity is less.

This research communication scrutinizes the time-dependent radiated stagnation point flow by a movable Riga surface in the presence of porous medium, mixed convection, viscous dissipation and radiative heat flux. Both electro-magneto effects are accounted for. The considered flow problem comprises Copper (Cu) as a nanoparticle in a continuous phase fluid water (H₂O). The mathematical modeling depends on two main expressions, i.e., momentum equation of Navier-Stokes equation under certain conditions and temperature expression. The coupled system is further simplified via similarity transformations. Computational outcomes are computed by implementing bvp4c technique with the shooting concept. The obtained results are displayed graphically. It is noticed from the computations that both Nusselt number (NN) and skin friction coefficient (SFC) declined subject to increasing estimations of the unsteady variable. The final outcomes and main key points are listed in the conclusion section.

The control over microstructural characteristics of graphene oxide (GO) is one of the most serious issues in the domain of graphene synthesis as this affects the graphene’s properties, and functionality. In this study, the primary objective is electrochemical synthesis graphene in the presence of magnetic field that is applied externally. During the synthesis process, the magnetic field was applied in a direction that was perpendicular to the applied potential. This causes the electrolyte to spin flow around the cell. Subsequently, the goal is to provide a comparative analysis between the microstructural characteristics of graphene that has been synthesized in situ and ex situ magnetic field. The cylindrical graphite was used as an anode, and a carbon electrode that had been recovered from a waste dry cell battery was used as a cathode. The pre-oxidized graphite was sonicated (synthesized under magnetic field, and without magnetic field) in sterilized water for 10min with a probe-type sonicator and thermally reduced at same temperature i.e., 850^∘C followed by furnace cooling. The findings of the Raman spectroscopy, atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) characterizations indicate that the magnetic flux that was applied has a significant influence on the surface height and roughness, microstructure, and surface state, a structural disorder in comparison to when there was no magnetic field applied to the thermally reduced graphene oxide (rGO). On the other side, from the data obtained by XRD and TGA analysis, the applied magnetic field seems to have very little effect on phase, lattice parameter and thermal stability.

In this paper, we design optical geometric ferromagnetic illustration for recursional optical electromagnetic elastic microscale beams with optical fields. Thus, the modeling of recursional operator for Heisenberg ferromagnetic electromagnetic normalized optical optimistic density is characterized by using recursional operator with optical fields. Also, we collect new optical flexible electroosmotic electromagnetic normalized optimistic density. Finally, optical recursional magnetical flexible elastic microscale beam demonstrated the optical ring resonator.