Within the numerical simulation method applied to the Langevin equation, the escape problem of particle moving in the truncated quartic potential driven by two types of correlated Lévy noise, i.e., Ornstein–Uhlenbeck Lévy noise and harmonic velocity Lévy noise, is studied. The dependence of the escape rate on the noise intensity parameter, the Lévy index, the noise correlation, and the particle mass

Molecular dynamics simulations often adopt coarse-grained (CG) models to investigate length- and time-scales that cannot be effectively addressed with atomically detailed models. However, the effective potentials that govern CG models are configuration-dependent free energies with significant entropic contributions that have important consequences for the transferability and thermodynamic properties

We investigate the behavior of three-dimensional 3D exchange energy functional of density-functional theory in anisotropic systems with two-dimensional 2D character and 1D character. The local density approximation (LDA), the generalized gradient approximation (GGA), and the meta-GGA behave as functions of quantum well width. We use the infinite-barrier model (IBM) for the quantum well. In the first

Understanding transport processes in complex nanoscale systems, like ionic conductivities in nanofluidic devices or heat conduction in low-dimensional solids, poses the problem of examining fluctuations of currents within nonequilibrium steady states and relating those fluctuations to nonlinear or anomalous responses. We have developed a systematic framework for computing distributions of time integrated

The reversal of magnetisation has been studied in a three-dimensional Ising ferromagnet by Monte Carlo simulation with Metropolis single spin flip algorithm using random updating scheme. The outer layers are considered as surface. The surface interacts with core with a relative ferromagnetic interaction strength. Depending on the relative interaction strength, the time of reversal of the surface was

The refractive index of dielectrics is a function of the density, temperature, and the wavelength of the incident light. The refractive index and material dispersion are determined by the plasma and the resonance frequencies. Physically, the forced oscillation of an induced dipole is driven by the light wave, vibrating in the plane perpendicular to the propagation direction of light. The incident light

In this paper, we study the dynamics of quantum Fisher information of a qubit interacting with a squeezed thermal environment. We obtain the optimal initial state of the qubit, the temperature of the environment, and the interaction time, which maximize quantum Fisher information. Based on the ohmicity of the environment, we compare the dynamics of quantum Fisher information in ohmic, sub-ohmic, and

We report on the derivation of analytical equations for ab-initio calculations of the strain dependence of crystal-electric-field (CEF) parameters for arbitrary deformations. The calculation is based on the fundamental assumption that the charge distribution deforms in the same way as the crystal. Based on this deformed-charge model, simple formulas for the practical usage are given for various site

In this study, the effects of hydrostatic pressure, temperature, and high-frequency intense laser field on the nonlinear optical properties of an asymmetric GaAs/AlGaAs double quantum well was theoretically investigated. For this, firstly, the energy eigenvalues and eigenfunctions of the system have been obtained using the effective-mass and parabolic band approximation. Later, the nonlinear optical

We construct soliton solution of a variable coefficients nonlinear Schrödinger equation in the presence of parity reflection–time reversal \((\mathscr {PT})-\) symmetric Rosen–Morse potential using similarity transformation technique. We transform the variable coefficients nonlinear Schrödinger equation into the nonlinear Schrödinger equation with \(\mathscr {PT}-\)symmetric potential with certain

Fermion bound states at the center of the core of a vortex in a two-dimensional superconductor are investigated by analytically solving the Bogoliubov–de Gennes equations in a magnetic field. The metallic surface states of a strong topological insulator become superconducting via proximity effect with an s-wave superconductor. Due to the magnetic field, the states undergo Landau quantization. A zero-energy

We present a microscopic study of the electronic and magnetic properties of the spin ladder systems Sr\(_{2}\)Fe\(_{3}\)Ch\(_{2}\)O\(_{3}\) (Ch=S, Se) based on density functional calculations and on ab initio-derived effective models. We discuss explicitly the nature of the exchange paths and provide quantitative estimates of magnetic exchange couplings. Although both compounds have similar crystal

A Correction to this paper has been published: https://doi.org/10.1140/epjb/s10051-021-00106-x

We investigate the drift and Hall mobility of a quasi-two-dimensional electron gas (Q2DEG) confined in wurtzite AlGaN/GaN/AlGaN square quantum wells (QWs). We use the variational-subband-wave-function model for carrier confinement and assume that the electrons only occupy the lowest subband. We take into consideration the most important scattering mechanisms such as the edge and charged dislocation

Two-person games are used in many multi-agent mathematical models to describe pair interactions. The type (pure or mixed) and the number of Nash equilibria affect fundamentally the macroscopic behavior of these systems. In this paper, the general features of Nash equilibria are investigated systematically within the framework of matrix decomposition for n strategies. This approach distinguishes four