Modern Physics Letters B

This paper obtains the stationary optical 1-soliton solution of the nonlinear Schrödinger's equation with dual-power law nonlinearity. The technique of Lie symmetry is used to obtain the solution.

We study spin transport properties in non-magnetic heterostructures in the presence of different spin-orbit interactions. For an unpolarized beam with zero angle of incidence, the transmitted spin-up and spin-down electrons will propagate in the same direction with similar amplitudes and different phases. The two beams will interfere with each other after passing through a certain distance of spin-orbit region. This effect just resembles the interference of polarization of light passing through wave plate. This quantum interference will shed light on quantum information processing and quantum computation.

A three-dimensional (3D) electrical action potential propagation model is developed to characterize the integrated effect of cardiac tissue structure using a homogenous function with a spatial inhomogeneity. This method may be more effective for bridging the gap between computational models and experimental data for cardiac tissue anisotropy. A generalized 3D eikonal relation considering anisotropy and a self-similar evolution solution of such a relation are derived to identify the effect of anisotropy and predict the anisotropy-induced electrical wave propagation instabilities. Furthermore, the phase field equation is introduced to obtain the complex three-dimensional numerical solution of the new correlation. The present results are expected to be valuable for better understanding the physiological behavior of cardiac tissues.

The aim of this work is to correlate the results of experimental data by using the differential thermal analysis (DTA) method and predictions of artificial neural networks (ANNs). Thermal decomposition of potassium nitrate (KNO₃) and benzoic acid (C₆H₅COOH) have been analyzed by the simultaneous DTA method. Kinetic parameters (critical points, the change of enthalpy) have been investigated. A computer model, based on multilayer feed-forwarding back-propagation is used for the prediction of critical points, phase transitions of potassium nitrate (KNO₃) and benzoic acid (C₆H₅COOH). As a result of our study, we conclude that the ANN model shows a considerably good result about the prediction of experimental data.

By using the Lewis–Riesenfeld invariant theory, we have studied the geometric phase in the condensed vapor of Rb under pressure and external time-dependent magnetic field. We find that the geometric phase in the cycle case has nothing to do with the coupling constant between electron and atomic nucleus, and the external time-dependent magnetic field.

In this letter, we present a family of plane symmetric solutions for the radiating gravitational field which satisfy the weak and dominant energy conditions. An example is given according to the general form. We show that the example is a space–time-periodic solution which may have some relations with the new physical phenomena.

A carbon nanotube (CNT) Schottky diode based on coaxial geometry is presented. We show that coaxially gated CNT field effect transistors (FETs) with a p-type semiconducting single-walled carbon nanotube (s-SWNT) and asymmetric contacts can provide good diode characteristics. The effect of different physical and electrical parameters such as gate bias voltage, gate insulator thickness, and CNT diameter on the rectification current–voltage characteristics is investigated. We demonstrate that it is possible to tune the rectification characteristic, threshold voltage, reverse saturation current, and reverse turn-on voltage by using these parameters.

The gyromagnetic factors for Fe³⁺ in ZnX (X=O, S, Se, Te) are theoretically studied from the perturbation formula of the g-factor for a 3d⁵ ion in tetrahedra based on inclusion of both the crystal-field and the charge-transfer contributions. The related model parameters in the calculations are determined from the cluster approach in a uniform way. The g-shift Δg (= g-g_s, where g_s ≈ 2.0023 is the spin-only value) from the charge-transfer contributions is opposite (positive) in sign and much larger in magnitude as compared with that from the crystal-field ones. The importance of the charge-transfer contributions increases rapidly with increasing the covalency and the spin-orbit coupling coefficient of the ligand and thus exhibits the order of O^2- < S^2- < Se^2- < Te^2-. The calculated g-factors by considering both the crystal-field and charge-transfer contributions show reasonable agreement with the experimental data for all the Fe³⁺ centers in ZnX.

We show the formation of slow optical solitons in the asymmetric coupled double quantum wells (CQW) via a two-photon Raman resonance. With the consideration of real parameters in AlGaAs-based CQW, we indicate the possibility to have cancelation of the linear absorption, giant Kerr nonlinearities, and slow group velocity propagation of the weak probe pulse at the same one-photon detuning frequency around several THz.

The effect of cadmium substitution and sintering temperature on the microstructure and dielectric properties of nano ZnCd_xFe_2-xO₄ ferrites (x=0.0, 0.05, 0.1, 0.2, 0.3 and 0.5) has been investigated and prepared by egg-white technique. Electrical conductivity and dielectric measurements have been analysed in the frequency range from 100 Hz to 10 MHz. The variation of the real (ε′) and imaginary (ε″) part of dielectric constant, AC conductivity (σ_AC) and loss tangent (tan δ) with frequency has been studied. It follows the Maxwell–Wagner model based on the interfacial polarization in consonance with the Koop's phenomenological theory. It is found that the permittivity of ZnCd_xFe_2-xO₄ ferrites improved and shows a maximum value (~9 × 10³) at 100 Hz for the x=0.1 sample.

We analyze the heat capacity C_P for low and high-density amorphous ice below the transition temperature (T_C ≈ 140 K) using a power-law formula. The renormalized critical exponent α_R is extracted from the observed C_P data, which describes similar critical behavior for both low and high-density amorphous ice below T_C. Our analysis can also describe a glass transition in the low-density amorphous ice which is made from the high-density amorphous ice at 124 K, as observed experimentally.