Modern Physics Letters B

Fingerprint recognition systems are susceptible to artificial spoof fingerprint attacks, like molds manufactured from polymer, gelatin or Play-Doh. Presentation attack is an open issue for fingerprint recognition systems. In a presentation attack, synthetic fingerprint which is reproduced from a real user is submitted for authentication. Different sensors are used to capture the live and fake fingerprint images. A liveness detection system has been designed to defeat different classes of spoof attacks by differentiating the features of live and fake fingerprint images. In the past few years, many hardware- and software-based approaches are suggested by researchers. However, the issues still remain challenging in terms of robustness, effectiveness and efficiency. In this paper, we explore all kinds of software-based solution to differentiate between real and fake fingerprints and present a comprehensive survey of efforts in the past to address this problem.

Chiral metamaterial-based sensor is designed for sensing the change in substance ratio of chemical substances when combined with distilled water. These samples have been prepared with 10%, 50% and 90% volume fraction of methanol, ethanol, acetone, ammonia and isopropyl alcohol. The complex permittivity of the prepared samples has been measured by Agilent 85070E dielectric probe kit and compared with the simulations. In the proposed design, linear shifts with the frequency bands of more than 100 MHz are observed in different measurements. For different material sensing, pure samples have been used and their reflection coefficient measurement results have been presented. Unique side of this study is that the structure provides very clear and sensitive results and presents a new approach to the microfluidic sensor applications by using the sample holder.

This research paper studies the optical soliton wave solutions of the model of sub-10-fs-pulse propagation by the implementation of the modified Khater method. This model describes the dynamics of light pulses that represent a higher-order nonlinear Schrödinger equation with the non-Kerr nonlinear term. The validity of this model depends on one primary hypothesis, which is the carrier wavelength of the soliton is much shorter than the spatial width. This means that the amplitude of the soliton frequency must be less than the carrier frequency. The shorter femtosecond pulses ($<$100 fs) are desired to increase the bit rate of pulse propagation. The losing of distribution in such short-wavelength pulses through waveguides is a negligible loss. Our solitary analytical wave solutions are approved with the waveguide made of highly nonlinear optical materials.

In this paper, aluminum-doped Ni–Cu–Co ferrite nanomagnetic material powder was prepared by sol–gel technique using citric acid as a complexing agent and high-purity nitrate as raw material. The effect of doping amount of different Al${}^{3+}$ ions on the structure and magnetic properties of ferrites has been studied. The X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), Energy dispersive X-ray (EDX) and Vibrating sample magnetometer (VSM) were used to characterize the structural and magnetic properties of ferrite. The XRD analysis showed that all samples of Ni–Cu–Co ferrites have a single-phase cubic spinel structure. Average crystallite size was calculated by the Debye–Scherrer formula and it was found that the average crystallite size of the sample was affected by the doping concentration. As the amount of Al${}^{3+}$ ion doping increases, the crystallite size decreases from 54.88 nm to 46.09 nm. The absorption peak of Fourier transform infrared spectroscopy (FTIR) at 590 cm${}^{-1}$ further indicates the formation of cubic spinel structure of Ni–Cu–Co ferrite. Transmission electron microscopy (TEM) images show the presence of particles which are spherically cubic-shaped particles. The constituent elements of the samples were analyzed by EDX spectroscopy. In addition, the ferromagnetism of the samples was confirmed by VSM measurements. The saturation magnetization (Ms) and remanent magnetization (Mr) first increase and then decrease when the aluminum ion concentration increases. Compared with pure samples and other doped samples, they have the best magnetic properties when the doping amount of Al${}^{3+}$ ions is $x=0.05$. It also shows that the prepared samples are suitable for magnetic recording materials.

Under investigation in this paper is the variable coefficient three-coupled nonlinear Schrödinger (CNLS) equations, which govern the dynamics of solitonic excitations along three-spine $\alpha$-helical protein with inhomogeneous effect. Via the Hirota method and symbolic computation, the exact two-bright-one-dark (TBD) and one-bright-two-dark (BTD) soliton solutions are constructed analytically. The propagation properties are discussed for TBD and BTD solitons when the variable coefficient is a hyperbolic secant function. Figures are plotted to reveal the following interactions of TBD and BTD two solitons: (1) Evolution without interactions of double-parabola-shaped solitons, of double-$S$-shaped solitons and of parabola-$S$-shaped solitons; (2) Evolution with periodic interaction of double-parabola-shaped solitons and of parabola-$S$-shaped solitons; (3) Collision of double-$S$-shaped solitons and of parabola-$S$-shaped solitons.

The influence of Molybdenum diselenide transition metal dichalcogenide material (p-type MoSe₂ TMDC) as an interfacial layer between the ultra-thin Cu (In, Ga)Se₂ (CIGS) absorber layer, with thickness less than 500nm, and molybdenum back contact was studied using SCAPS-1D simulation package. The possible effects of the p-MoSe₂ layer on the electrical properties and the photovoltaic parameters of the CIGS thin-film solar cells have been investigated. Band gap energy, carrier concentration, and the layer thickness of the p-MoSe₂ were varied in this study. The optimum band gap is found to be of 1.3 eV. Interfacial layers of thicknesses less than 200 nm have been found to cause deterioration for the overall cell performance. This might be attributed to the increase in the back-contact recombination current and the reduction of the built-in potential at p-MoSe₂/CIGS junction. Furthermore, the MoSe₂ layer would form the so-called back surface field (BSF), due to the associated wider band gap with respect to that of CIGS absorber layer. Additionally, the simulation of the I–V characteristic showed a higher slope which implies that MoSe₂ layer at the CIGS/Mo interface acts in a beneficial way on the CIGS/Mo hetero-contact adapting it from Schottky type contact to quasi-ohmic contact. The conversion efficiency has increased significantly from 14.61% to 22.08%, without and with the MoSe₂ layer, respectively. These findings are very promising for future high performance and cost-effective solar cell devices.

The crystal structure and thermal properties of AgCuS compound were investigated at high temperature ranges. It was found that the crystal structure of these compounds has orthorhombic symmetry with Cmcm space group at the normal condition and room temperature. The phase transition to cubic symmetry with Fm3m space group is observed at $T=930\mathrm{\text{K}}$ temperature. The endoeffect was observed with a central peak at $T=938\mathrm{\text{K}}$ in the differential thermal analysis. The temperature dependence on heat capacity was obtained in the range of $300\mathrm{\text{K}}\le T\le 1300\mathrm{\text{K}}$ temperature. Thermodynamic parameters have been determined: enthalpy and heat capacity. The value of enthalpy was calculated according to the temperature of the phase transition.

An entanglement concentration protocol in photonic collective-rotating decoherence-free subspace (CRDFS) is proposed. To accomplish the scheme, two methods to construct parity measurement devices in CRDFS are presented by exploiting the cross-Kerr nonlinearity, through which partially entangled states are converted to maximally entangled states. The performance of the protocol can be improved by iteration method. Fidelity in consideration of dissipation is discussed, which demonstrates good robustness. In contrast to the conventional protocols, the present one has distinctive feature since it can not only get maximally entangled state from less entangled state, but also maintain the maximal entanglement in collective-rotating noise environment.

An integrable extension of the famous Schrödinger equation in (2+1) dimension, named Kundu–Mukherjee–Naskar (KMN) equation, governing the evolution of ion-acoustic wave in magnetized plasma and oceanic rogue waves is considered, and dark/black as well as gray optical soliton solutions are constructed by using a complex envelope ansatz approach with appropriate conditions for the existence of solitons. Also, a new class of combined gray and black optical soliton solutions is obtained by applying Chupin Liu’s theorem, and it is found to be anti-dark solitons. Additionally, Gaussian wave solutions are derived. Further, the investigation of symmetry analysis, nonlinear self-adjointness and conservation laws (Cls) for the KMN equation are carried out. These results further enrich and deepen the understanding of the dynamics of a higher-dimensional soliton propagation.

This paper presents some exponential function solutions of the (3+1)-dimensional space-time fractional modified KdV–Zakharov–Kuznetsov (mKdV–ZK). The improved Bernoulli sub-equation function method (IBSEFM) is used in carrying out this computation. Choosing the suitable parameters, the 2D and 3D surfaces of solutions are plotted. The constructed results may be useful in explaining the physical meaning of the studied model.

In this paper, we present a coupled sine-Gordon (CSG) system, which describes the dynamics of two deoxyribonucleic acid (DNA) twisting strands in open configuration. We investigate the associated linear eigenvalue problem of the CSG system and obtain generalized formulae for multiple soliton solutions by employing the Darboux transformation (DT). Explicit expressions of one- and two-kink and line soliton solutions, single breather and first-order degenerate solutions are obtained by using particular solutions to the associated linear eigenvalue problem. We also present the dynamics of the different solutions.

This paper presents a new lattice hydrodynamic model with vehicle overtaking and the continuous self-delayed traffic flux integral. The linear stability condition of the model is derived through the linear stability analysis, which shows that the stable region can be enlarged by increasing the step of delay time. The modified Korteweg–de Vries (mKdV) equation is formulated through nonlinear analysis to describe the propagating behavior of traffic density wave near the critical point. The kink–anti-kink solution under different passing constants is also obtained. Results show that when the passing constant is lower than a threshold (Case I) that is associated with the delay time step, uniform flow and kink jam phase exhibits, and jamming transition occurs between the uniform flow and kink jam. When the passing constant exceeds the threshold (Case II), jamming transitions occur from uniform traffic flow to kink-Bando traffic wave through chaotic phase with decreasing sensitivity. Simulation examples verify that when the delay time increases from 0 to 0.6, the fluctuation amplitude of the traffic density is reduced from 0.07 to 0 even with exogenous initial disturbance, whereas under Case II, chaotic traffic flow appears when the density ranges from 0.18 to 0.31 and the delay time is 0.6.

A composite square zone plate (CSZP) is proposed to generate two two-arms-cross patterns with equal intensity and arbitrarily designed axial positions. Moreover, the CSZP with the spiral phase has two square optical vortices located at the arbitrary positions. In addition, we find that the same topological charge of twin square optical vortices for the CSZP follows a modulo-4 transmutation rule. The construction method of proposed zone plates is illustrated in detail. We prove numerically and experimentally that the CSZP and spiral-phase CSZP produce two tailorable two-arms-cross patterns with equal intensity and square optical vortices, respectively. The proposed zone plate can be used to generate hollow beams and have potential applications in infrared antennas and laser alignment systems.

In this paper, via 12-particle entangled states as quantum channels, two schemes for cyclic quantum teleportation are proposed by using two different measurement methods, one is the Bell state measurement, the other is single-particle measurement. Besides, these schemes can be generalized to realize the probabilistic teleportation of an unknown multi-particle high-dimension state. Furthermore, feasibility for the schemes and some conclusions are discussed at the end of this paper.