arXiv subjects

Mahdi Eshghi

Publications and source records attributed to Mahdi Eshghi.

10 recordsLinked to original sources

arXiv2020

Scattering Amplitude Together with Thermodynamic Properties in the Poschl-Teller Double Ring-Shaped Coulomb Potential

We obtain the exact solution to the Dirac equation with the Poschl-Teller double ring-shaped Coulomb (PTDRSC) potential for any spin-orbit quantum number K. The relativistic scattering amplitude for spin 1/2 particles in the field of this potential has been studied. The wave functions are expressed in terms of the hyper-geometric series of the continuous states on the K/2Pi scale. A formula for the phase shifts has also been found. In the nonrelativistic limits, our solution to the Dirac system converges to that of the Schrödinger one. At the high temperature, the partition function is calculated in order to study the behavior of some thermodynamic properties.

quant-ph↗

arXiv2019

Quantum Pseudodots Under the External Vector and Scalar Fields

We study the spherical quantum pseudodots in the Schrodinger equation using the pseudo-harmonic plus harmonic oscillator potentials considering the effect of the external electric and magnetic fields. The finite energy levels and the wave functions are calculated. Furthermore, the behavior of the essential thermodynamic quantities such as, the free energy, the mean energy, the entropy, the specific heat, the magnetization, the magnetic susceptibility and the persistent currents are also studied using the characteristic function. Our analytical results are found to be in good agreement with the other works. The numerical results on the energy levels as well as the thermodynamic quantities have also been given.

quant-ph↗

arXiv2019

Thermal and optical properties of two molecular potentials

We solve the Schrödinger wave equation for the generalized Morse and Cusp molecular potential models. In the limit of high temperature, at first, we need to calculate the canonical partition function which is basically used to study the behavior of the thermodynamic functions. Based on this, we further calculate the thermodynamic quantities such as the free energy, the entropy, the mean energy and the specific heat. Their behavior with the temperature has been investigated. In addition, the susceptibility for two level systems is also found by applying the incident time dependent field.

quant-ph↗

arXiv2017

Calculations of the Decay Transitions of the Modified Poschl-Teller Potential Model via Bohr Hamiltonian Technique

We calculate the eigenvalues and their corresponding eigenfunctions of the Bohrs collective Hamiltonian with the help of the modified Poschl-Teller potential model within -unstable structure. Our numerical results for the ground state beta and gamma band heads together with the electric quadrupole B(E2) transition rates are displayed and compared with those available experimental data.

nucl-th↗

arXiv2017

Energy states of the Hulthen plus Coulomb-like potential with position-dependent mass function in external magnetic fields

We need to solve a suitable exponential form of the position-dependent mass (PDM) Schrödinger equation with a charged particle placed in the Hulthen plus Coulomb-like potential field and under the influence of the external magnetic and Aharonov-Bohm (AB) flux fields. The bound state energies and their corresponding wave functions are calculated for spatially-dependent mass distribution function of a physical interest. A few plots of some numerical results to the energy are shown.

quant-ph↗

arXiv2017

Killingbeck Mass Spectrum of Heavy Quarkonia Under the Influence of External Magnetic and AB Flux Fields

We present a more general form of the Schrödinger equation in curvilinear space that is exposed to external fields. Thereby, we solve the wave equation with the Cornell plus harmonic potentials (CHP) under the influence of the magnetic and Aharonov-Bohm (AB) flux fields using curvilinear coordinates system in such space. With this requirement, the energy spectrum and the corresponding wave functions are calculated by means of the series method. The mass spectrum of both charmonium and bottomonium states consisting of quark and antiquark are calculated. In addition, the main thermodynamic functions such as the free energy, the mean energy, the entropy, the specific heat, the persistent currents and magnetization are obtained by using the characteristic function. We draw the resulting energy states and the thermodynamic quantities versus some potential parameters, magnetic field and temperature to see their numerical behaviors. Finally, we give some discussions to our results.

quant-ph↗

arXiv2016

Approximate energy states and thermal properties of a particle with position-dependent mass in external magnetic fields

We solve the Schrödinger equation with a position-dependent mass (PDM) charged particle interacted via the superposition of the Morse and Coulomb potentials and exposed to external magnetic and Aharonov-Bohm (AB) flux fields. The non-relativistic bound state energies together with their wave functions are calculated for two spatially-dependent mass distribution functions. We also study the thermal quantities of such a system. Further, the canonical formalism is used to compute various thermodynamic variables for second choosing mass by using the Gibbs formalism. We give plots for energy as a function of various physical parameters. The behavior of the internal energy, specific heat and entropy as functions of temperature and mass density parameter in the inverse-square mass case for different values of magnetic field are shown.

quant-ph↗

arXiv2016

Relativistic Killingbeck Energy States Under an External Magnetic Fields

We address the behavior of the Dirac equation with the Killingbeck radial potential including the external magnetic and Aharonov-Bohm (AB) flux fields. The spin and pseudo-spin symmetries are considered. The correct bound state spectra and their corresponding wave functions are obtained. We seek such a solution using the biconfluent Heun differential equation method. Further, we give some of our results at the end of this study. Our final results can be reduced to their non-relativistic forms by simply using some appropriate transformations. The spectra, in the spin and pseudo-spin symmetries, are very similar with a slight difference in energy spacing between different states.

quant-ph↗

arXiv2016

Feinberg-Horodecki States of Time-Dependent Mass Distribution Harmonic Oscillator

The solution of the Feinberg-Horodecki (FH) equation for a time-dependent mass (TDM) harmonic oscillator quantum system is studied. A certain interaction is applied to a mass to provide a particular spectrum of stationary energies. The related spectrum of the harmonic oscillator potential acting on the TDM oscillators is found. We apply the time version of the asymptotic iteration method (AIM) to calculate analytical expressions of the TDM stationary state energies and their wave functions. It is shown that the obtained solutions reduce to those of simple harmonic oscillator as the time-dependent of the mass reduces to

quant-ph↗

arXiv2012

Exact solutions of a spatially-dependent mass Dirac equation for Coulomb field plus tensor interaction via Laplace transformation method

The spatially-dependent mass Dirac equation is solved exactly for attractive scalar and repulsive vector Coulomb potentials including a tensor interaction potential under the spin and pseudospin (p-spin) symmetric limits by using the Laplace transformation method (LTM). Closed forms of the energy eigenvalue equation and wave functions are obtained for arbitrary spin-orbit quantum number Some numerical results are given too. The effect of the tensor interaction on the bound states is presented. It is shown that the tensor interaction removes the degeneracy between two states in the spin doublets. We also investigate the effects of the spatially-dependent mass on the bound states under the conditions of the spin symmetric limit and in the absence of tensor interaction

math-ph↗