International Journal of Modern Physics B

The Publisher has retracted this article per the authors' request. Please contact the authors (alextianming@126.com) for more details about this retraction.

Exclusion processes are hot study issues in statistical physics and corresponding complex systems. Among fruitful exclusion processes, totally asymmetric simple exclusion process (namely, TASEP) attracts much attention due to its insight physical mechanisms in understanding such nonequilibrium dynamical processes. However, interactions among isolated TASEP are the core of controlling the dynamics of multiple TASEPs that are composed of a certain amount of isolated one-dimensional TASEP. Different from previous researches, the interaction factor is focused on the critical characteristic parameter used to depict the interaction intensity of these components of TASEPs. In this paper, a much weaker constraint condition ${\prod }_{i=1}^K{\omega }_i^d={\prod }_{i=1}^K{\omega }_i^u$ is derived as the analytical expression of interaction factor. Self-propelled particles in the subsystem $i$ of multiple TASEPs can perform hopping forward at $p_i$, moving into the target site of the (i − 1)th TASEP channel at ${\omega }_i^u$ or updating into the (i + 1)th TASEP channel at ${\omega }_i^d$. The comparison of this proposed interaction factor and other previous factors is performed by investigating the computational efficiency of obtaining analytical solutions and simulation ones of order parameters of the proposed TASEP system. Obtained exact solutions are observed to match well with Monte Carlo simulations. This research attempts to have a more comprehensive interpretation of physical mechanisms in the impact of interaction factors on TASEPs, especially corresponding to stochastic dynamics of self-propelled particles in such complex statistical dynamical systems.

This paper proposes a novel model to attain high birefringence and low loss in a slotted core-based photonic crystal fiber (PCF) structure in THz regime. The performance of the proposed PCF has been evaluated by applying finite element method (FEM) with full simulation software COMSOL Multiphysics V-5.1. The proposed model gains good optical properties such as high birefringence of 0.24, low effective material loss (EML) of 0.03 cm${}^{-1}$, low confinement loss of 6.5 × 10${}^{-13}$ (dB/m), low scattering loss of 2 × 10${}^{-3}$ (dB/m) and low bending loss of 7.4 × 10${}^{-20}$ (dB/cm). The proposed structure also exhibits the flattened dispersion for wider frequency response. However, the real-life fabrication of the suggested model is highly feasible using the current technology due to the unique shape of circular air holes in the cladding region. The outcomes make the proposed PCF a stronger candidate for polarization-preserving applications such as sensing, communications and filtering operations in THz band.

By using the transfer matrix method, the theoretical investigation has been carried out in the near- and mid-infrared bandgaps for a periodic multilayered structure that was composed of superconductor (SC) and semiconductor-metamaterial. It was found that two bandgaps appeared within the computational regions which are effectively optimized by manipulating the thickness of the SC film, fill factor of the semiconductor-metamaterial and the incidence angle of the incident electromagnetic wave. However, the thickness of the SC film and fill factor of the semiconductor-metamaterial are responsible for the red-shift of bandgaps, while the blue-shift is accounted for by the angle of incidence for both transverse electric (TE) and transverse magnetic (TM) waves. It is notable, for the TM wave, that the bandgaps disappeared at the incident angles of approximately 60${}^{\circ }$. Such properties are quite useful in designing any new types of edge filters and other optical devices in the near- and mid-infrared frequencies.

Recently, many results, namely the Fluctuation theorems (FT), have been discovered for systems arbitrarily away from equilibrium. Many of these relations have been experimentally tested. The system under consideration is usually driven out of equilibrium by an external time-dependent parameter which follows a particular protocol. One needs to perform several iterations of the same experiment in order to find statistically relevant results. Since the systems are microscopic, fluctuations dominate. Studying the convergence of relevant thermodynamics quantities with number of realizations is also important as it gives a rough estimate of the number of iterations one needs to perform. In each iteration, the protocol follows a predetermined identical/fixed form. However, the protocol itself may be prone to fluctuations. In this work, we are interested in looking at a simple nonequilibrium system, namely a Brownian particle trapped in a harmonic potential. The center of the trap is then dragged according to a protocol. We however lift the condition of fixed protocol. In our case, the protocol in each realization is different. We consider one of the parameters of the protocol as a random variable, chosen from some known distribution. We study the systems analytically as well as numerically. We specifically study the convergence of the average work and free energy difference with number of realizations. Interestingly, in several cases, randomness in the protocol does not seem to affect the convergence when compared to fixed protocol results. We study symmetry functions. The cases of a Brownian particle in a harmonic potential with sinusoidally changing stiffness constant, as well as a Brownian particle in a double well potential, are also studied. We believe that our results can be experimentally verified.

In this study, an eleven-parameter rigid-ion model (RIM) is proposed for BaFX (X = Cl, Br and I) matlockite structure compounds. The interatomic interactions up to fourth nearest neighbors for the studied compounds are calculated. The zone-center raman and infrared phonon mode frequencies, elastic constants, bulk modulus B, shear modulus G, Young’s modulus E, Poisson’s coefficient, Debye temperature and sound velocity along [100], [110] and [001] directions have been calculated. It is observed that the studied BaFCl, BaFBr and BaFI compounds are stiffer in [100] direction than [001] crystallographic direction and the bulk modulus, shear modulus and Young’s modulus of the studied compounds decrease in the order of BaFCl $>$ BaFBr $>$ BaFI. The obtained results are compared with the theoretical and experimental results. It is observed that the obtained results agree very well with the experimental and theoretical results available in the literature.

In this paper, crystallization pathway and dynamical heterogeneity (DH) in iron nanoparticle (NP) have been investigated in detail for spherical samples containing 5000 atoms, which were obtained by the molecular dynamics simulation based on Pak–Doyama potential. The crystallization was analyzed through pair radial distribution function, angle distribution, parameter $〈$F${}_{\mathrm{\text{bcc}}}〉$ and transition to different x-types, where x is the bcc, fcc-hcp, ico, 14 or 12. We found that transitions to bcc-type do not happen arbitrarily at any location in NP, but instead they are concentrated in a nonequilibrium region. The crystallization pathway comprises of intermediate states between amorphous and crystalline ones. At the early stage, a large cluster of Cryst-atom formed is located in a middle layer of NP. Then, this cluster grows up and the parameter $〈$F${}_{\mathrm{\text{bcc}}}〉$ for it increases rapidly. At the final stage, the cluster of Cryst-atom is located in a well-equilibrium region covering a major part of NP. It is found that the structure of amorphous and crystalline NPs is strongly heterogeneous and consists of separate regions with different local microstructure. This indicates the DH in NP. We also found that there is a connection between local structures and DH in NP.

The effect of high-energy electron beam on the silicon carbide nanopowder’s structural parameters, strain and powder size was studied. The sample was irradiated with $\sim$2-MeV electron beam energy under different fluencies such as 1.13 ⋅ 10${}^{17}$, 1.89 ⋅ 10${}^{17}$, 2.79 ⋅ 10${}^{17}$ and 3.69 ⋅ 10${}^{17}$ cm${}^{-2}$ at the linear electronic accelerator. Initial and irradiated samples at various doses have been analyzed in the XRD. The nanostructural effects within FullProf are treated using the pseudo-Voigt profile function. The dependences of maximum strain and nanocrystallite size on irradiation dose were obtained and analyzed.

By using the generalized exponential rational function method, we construct the analytical solutions of the mitigating internet bottleneck with quadratic-cubic nonlinearity involving the $\beta$-derivative. This equation is described to control internet traffic. A number of new optical soliton solution for them are calculated. Oblique optical solutions also emerge as a product of this integration scheme. The results are applicable to mitigate Internet bottleneck, which is a growing problem in the telecommunications industry.

The effects of external applied fields on the electron-related optical nonlinear properties in a short-range bottomless exponential potential quantum well are investigated. The potential profile behaves as inverse square root in the vicinity of the origin and vanishes exponentially toward infinity, supporting a finite number of bound states whose energies and wave functions are determined within the effective-mass approximation. The linear, third-order nonlinear and total optical absorption coefficients (TOACs) as well as the coefficient of relative refractive index changes (RRICs) of the system are calculated from the expressions derived in the framework of the compact density matrix approach. The results obtained after numerical calculations show that with the effect of the static electric and magnetic fields (high-frequency THz laser field), the resonant peak position of the optical response shifts toward higher (lower) energies and the magnitude of the peak increases.

We investigate the evolution of the difference in the conventional logistic map and observed complicated but interesting dynamics. Our results show that the bifurcation, the attractor and the asymptotic measure depend on initial values. The reverse bifurcation, the multiple bifurcation and other bifurcation properties obtained here are different from those of the original logistic map. Furthermore, we find that attractors form a structure which looks like a jigsaw puzzle, and the corresponding distributions related to the Feigenbaum constant are also analyzed.

The structural, mechanical and electronic properties of recently reported superhard material C${}_{28}$ are studied by first-principles calculations. The unit cell of C${}_{28}$ is composed of 28 carbon atoms and all sp³ hybridized bonds. From 0 GPa to 100 GPa, C${}_{28}$ satisfies the mechanical stability criteria and the phonon spectrum of C${}_{28}$ has no imaginary frequency, which means that C${}_{28}$ is mechanically and dynamically stable. The results of hardness calculated show that C${}_{28}$ is a potential superhard material with the Vickers hardness of 84.0 GPa. By analyzing the elastic anisotropy, we found that elastic anisotropy of C${}_{28}$ increases with pressure. The calculations of band structure demonstrates that C${}_{28}$ is an indirect bandgap semiconductor with the gap of 4.406 eV. These analyses demonstrate C${}_{28}$ is a superhard semiconductor material.

Proposing realistic hybrid traffic flow model is a promising and hot topic in the area of fluid mechanics and nonlinear dynamics, since they can take advantages of combining dynamical properties of each individual vehicle and macroscopic characteristics of the global system. In this paper, different from the previous work, we propose a hybrid traffic flow model considering the dynamical competition between ramps and main roads. Afterwards, the dynamical control equations of the proposed system are established. Then, by means of performing finite difference analyses, nonlinear dynamical characteristics and specific properties of the proposed system are investigated. Evolvement laws of characteristic order parameters of the proposed traffic flow system are obtained by analyzing the change of density, velocity and current in various circumstances. Moreover, matrices of partition coefficient are employed into the proposed traffic network composed of a main road and varied ramps. Additionally, linear and nonlinear stability analyses are considered in different phase spaces. Therefore, the robustness of the proposed system is tested by both linear and nonlinear dynamics. Our work will be helpful to understand mesoscopic dynamical behaviors of each individual vehicle and inner interactions between them.

Totally asymmetric simple exclusion process (TASEP) is an important stochastic dynamic process in the area of statistical physics, which can be used to model microscopic transport in nonequilibrium processes. Due to its rich stochastic dynamics and nonequilibrium phase transition mechanisms, the importance of TASEP in statistical physics is similar with that of Ising model, which has attracted many attentions. In this paper, multiple TASEPs are introduced and coupled with various strong and weak interacting effects of self-driven particles. Both strong and weak couplings are calculated by means of mean-field analyses and Monte Carlo simulations. Tremendous cluster dynamics, evolution law of topological structures of phase diagrams and mechanisms of shock evolution are found in thermodynamic limit of proposed particle system. Monte Carlo simulation results like phase boundaries are found to be a good match with mean-field analyses, which reflect the validity of the research. The research work will be conducive to exploring the mechanisms of stochastic dynamics in the process of nonequilibrium phase transitions of multi-body interacting particle systems.