Modern Physics Letters B

In this work, the soliton solutions of a (3 + 1)-dimensional coupled nonlinear Schrödinger system with time-dependent coefficients arising in optical fiber has been studied analytically. A complex traveling wave ansatz is used to transform the proposed coupled partial differential equations into ordinary differential equations (ODEs). Then, we solved the obtained nonlinear ODEs for the envelope function in the traveling wave parameter. The obtained waves envelope have the forms of bright and dark soliton-like solutions which are considered as new solutions of the studied system. As a kind of completing the analysis, the modulation instability is discussed based on the linear stability analysis.

We investigate the mixed interaction solutions of the coupled nonlinear Schrödinger equations (CNLSE) through the Darboux transformation method. First of all, we derive the nonsingular localized wave solutions for two cases of CNLSE by the Darboux transformation method and matrix analysis method. Furthermore, we take a limit technique to deduce rogue waves and divide the rogue waves into four categories through analyzing their dynamic behaviors. Based on the obtained theorems, the Darboux transformations are presented to solve interaction solutions between distinct nonlinear waves. In this paper, we mainly study four types. Finally, the dynamic characteristics of the constructed these solutions are analyzed by sequences of interesting figures plotted with the help of Maple.

In this paper, using the principle of quantum state superposition, we report a nonclassical quantum state which is constructed by repeatedly operating the number operator on the coherent state. Nonclassical effects of this state are discussed by photon-number distribution, sub-Poissonian statistics, anti-bunching and negativity of Wigner function and squeezing effect. Our work provides an important nonclassical resource, which may be used in quantum communication and quantum optics.

This paper investigates the problem of finite-time $H_{\infty }$ synchronization for semi-Markov jump Lur’e systems with time-varying delay and external disturbance. The purpose of this work is to design a mode-dependent state-feedback controller to ensure that the synchronization-error system achieves finite-time synchronization with a prescribed $H_{\infty }$ performance index. A criterion for the finite-time synchronization is proposed by using appropriate Lyapunov functional and two recently developed inequalities. Then, a design method for the required state-feedback controller is presented with the application of several decoupling techniques. Finally, an example is provided to illustrate the applicability of the proposed control method.

Magnetic hyperthermia can improve therapeutic effects of chemotherapy drugs. Injectable magnetic hydrogels are considered as promising materials for synergistic treatments of magnetic hyperthermia and chemotherapy. However, most works only focused on Fe₃O₄ nanoparticles-based magnetic hydrogels, which cannot self-regulate hyperthermia temperature due to their high Curie temperature. In this paper, ${\mathrm{\text{Zn}}}_{0.54}{\mathrm{\text{Co}}}_{0.46}{\mathrm{\text{Cr}}}_{0.6}{\mathrm{\text{Fe}}}_{1.4}{\mathrm{\text{O}}}_4$ nanoparticles with Curie temperature at 45.7${}^{\circ }$C were introduced into chitosan/glycerophosphate/sodium hyaluronate hydrogels for preparing injectable magnetic hydrogels. The morphology, magnetic heating properties, rheological properties and drug release behaviors of magnetic hydrogels were investigated systematically. Magnetic heating experiments demonstrated that the magnetic hydrogels can self-regulate temperature at 42.6–43.1${}^{\circ }$C though magnetic phase transition, satisfy the temperature requirement of hyperthermia. In vitro adriamycin hydrochloride (DOX) release experiments demonstrated that the magnetic hydrogels can release DOX for more than 120 h, and their release processes were pH- and temperature-sensitive, which can improve the DOX utilization in clinical treatments. These data may provide useful information for further research on magnetic hydrogels-based multi-modal tumor therapy.

Two-dimensional (2D) magnonic crystal (MC) with an asymmetric complex basis is proposed in this paper, and its band structures are calculated in the whole area of the first Brillouin zone (BZ). This kind of MCs is composed of two different atoms in the unit cell, and the symmetry of the unit cell is broken due to changes in the position of the second atom, so the irreducible part of the BZ is no longer the small area $(\mathrm{\Gamma }XM)$ for square lattice, and it must be expanded to the whole first BZ. Only by investigating the whole first BZ, can we get the true full band-gap for this kind of MCs.

In this paper, we investigate the soliton molecules, asymmetric soliton and some novel hybrid solutions for the isospectral B-type Kadomtsev–Petviashvili (BKP) equation based on a new resonance condition. The soliton molecules and asymmetric soliton of the isospectral BKP equation can be obtained by selecting the appropriate parameters. Based on velocity resonance, module resonance and long-wave limit method, we can obtain the interactions of soliton molecules, breather waves and lump waves. Finally, we give the graphic of soliton molecules, asymmetric soliton and some novel hybrid solutions, and give the dynamic behavior analysis.

This study presents a simple electrochemical deposition route to obtain carbon-doped TiO₂ films. The deposition of the films is carried out on silicon substrates from a mixture of methanol (CH₃OH) and Titanium (IV) isopropoxide (Ti[OCH(CH₃)₂]₄) solution using a simple two-electrode electrodeposition setup. The obtained films are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-Visible diffuse reflectance spectroscopy (DRS) and conductivity measurements. Depending on the deposition conditions, both amorphous and crystalline TiO₂ films could be obtained. It is found that carbon is doped both substitutionally and interstitially. High carbon doping (up to 18.96%) enables to obtain TiO₂ film with narrowed bandgap and high conductivity to about 2.3 eV and $1.19\times 10^3$ S cm${}^{-1}$, respectively. This study suggests that the proposed electrodeposition route offers an easy way of obtaining conductive and narrowed bandgap TiO₂ films on large surface areas.

Based on Maxwell’s equations, we study the development of electromagnetic pulse instability in nonlinear electrodynamics beyond approximation of slowly varying amplitudes and phases. The action was chosen from the Heisenberg–Euler Lagrangian based on the invariants of the electromagnetic field. We analyze the scenario for the evolution of instability, which turns out to be consistent with the earlier conclusion done within the approximation of slowly varying amplitudes and phases. In this study, we take into account the influence of temperature. The rate of pair production under the Schwinger mechanism is estimated.

Electron transport characteristics through a system consisting of a series of triangular quantum dot rings are studied utilizing the non-equilibrium Green’s function. In the presence of a magnetic field, an additional anti-resonance point occurs in the conductance spectrum. As the number of triangular quantum dot rings increases, two anti-resonance points evolve into two well-defined insulating bands. The insulating band disappears as the magnetic flux takes an appropriate value, and therefore, an effective magnetically-controlled quantum switch can be achieved. If a Zeeman magnetic field is introduced, a spin-polarized window (SPW) can be formed, suggesting a physical scheme of a spin filtering. As the intradot Coulomb interactions are taken into consideration, more SPWs can be obtained. This work sheds lights onto the design of future quantum devices.

We investigate optimal perturbation and its transient growth characteristics in Taylor–Dean flow theoretically. The parameter $\beta$, accounting for the ratio of average pumping velocity induced by azimuthal pressure gradient to rotating velocity by rotating cylinders, is varied from −5 to 5. The results show that for the rigid rotation case, the energy growth of optimal perturbation is increased with increasing magnitude of azimuthal pressure gradient. Further, both the main and secondary peak of the amplitude of azimuthal velocity are seen to be shifted towards the outer cylinder for wide gap case, and both are shifted oppositely towards the inner cylinder for narrow gap case. Viewing the time evolution of the energies in the three velocity components for wide gap case, anti-lift-up mechanism replaces lift-up mechanism as the dominant mechanism for energy growth, when $\beta$ changes from −5 to 5. While for narrow gap case, lift-up mechanism is always responsible for transient growth of axisymmetric perturbation, no matter how strong azimuthal pressure gradient is considered.

In this paper, we investigate some two-dimensional (with respect to spatial independent variables) reaction–diffusion–convection equations with various nonlinear (reaction) terms. Using Hirota bilinear formalism with a free auxiliary function, we obtain kink solutions and many spatio-temporal discretizations having birational form.

This paper constructs a novel memristive hyperchaotic system by introducing the flux-controlled memristor to an extended jerk system. The memristive system has two equilibria and coexists two symmetric hyperchaotic attractors. The dynamic behaviors of the system are studied through bifurcation analysis. The analog circuit design and microcontroller-based experimental implementation of the system are presented. The synchronization of the system is realized by using the adaptive control technique. The sufficient conditions for synchronization are established via theoretical and numerical analysis.

The parent phase structure of Mn₂NiGa has always been controversial in the past decade. The ground state energy of the conventional cubic structure is higher than that of the Hg₂CuTi structure, while the widely accepted Hg₂CuTi structure for the parent phase does not satisfy with the mechanical stability criteria. In this work, a new configuration was found by the first-principles calculations. Its total energy is lower than that of the Hg₂CuTi structure. Moreover, the elastic constants of this new structure can satisfy the criteria of mechanical stability. This suggests that the newly proposed structure is more likely than Hg₂CuTi-type for the parent phase of the Mn₂NiGa alloys.

$N$-soliton solutions are derived for a (3 + 1)-dimensional potential-Yu–Toda–Sasa–Fukuyama (YTSF) equation by using bilinear transformation. Some local waves such as period soliton, line soliton, lump soliton and their interaction are constructed by selecting specific parameters on the multi-soliton solutions. By selecting special constraints on the two soliton solutions, period and lump soliton solution can be obtained; three solitons can reduce to the interaction solution between period soliton and line soliton or lump soliton and line soliton under special parameters; the interaction solution among period soliton and two line solitons, or the interaction solution for two period solitons or two lump solitons via taking specific constraints from four soliton solutions. Finally, some images of the results are drawn, and their dynamic behavior is analyzed.

A stop-band filter is discussed based on the strong coupling-like phenomenon in metal-insulator-metal (MIM) structures involving molecular J-aggregates. The structure is composed of a $\pi$-shaped resonator, an input waveguide and an output waveguide. The finite element method (FEM) method is employed in simulation. The results show that the strong coupling phenomenon appears with the Molecular J-aggregates. The small variations in size of the whole structure have little effect on stop bandwidth of the transmission spectrum and the stop bandwidth of the transmission spectrum in the designed structures is mainly determined by the oscillation strength of molecular J-aggregates. The larger the oscillation length of molecular J-aggregates part is, the wider the stop-band is.