The Physics Society of IranIranian Journal of Physics Research1682-695710120191126Topological solitons in DNA with modified potentialTopological solitons in DNA with modified potential18844FAEBehjatNRiaziJournal Article20191126DNA is not only an essential research subject for biologists, but also it raises very interesting questions for physicists.The open states in DNA double helix can lead to topological solitons. Since DNA is a very long molecule )of order a meter or so long) and nano-scale width, solitons can propagate along the molecule. In this paper, considering a correction term in the interaction potential between two chains, we study the dispersion relation analytically, and obtain the soliton solutions using a new relaxation method. Then we compare our solutions and its energy with those obtained by others without the proposed correction term.DNA is not only an essential research subject for biologists, but also it raises very interesting questions for physicists.The open states in DNA double helix can lead to topological solitons. Since DNA is a very long molecule )of order a meter or so long) and nano-scale width, solitons can propagate along the molecule. In this paper, considering a correction term in the interaction potential between two chains, we study the dispersion relation analytically, and obtain the soliton solutions using a new relaxation method. Then we compare our solutions and its energy with those obtained by others without the proposed correction term.https://ijpr.iut.ac.ir/article_844_e97ee2054defb209c35fe4dc94599061.pdfThe Physics Society of IranIranian Journal of Physics Research1682-695710120191126The effect of Ti substitution in Mn sites on the structural and electrical properties of La0.8Sr0.2MnO3 manganiteThe effect of Ti substitution in Mn sites on the structural and electrical properties of La0.8Sr0.2MnO3 manganite916845FABAslibeikiPKameli0000-0003-4490-0767HSalamatiJournal Article20191126In this study, the effect of Ti substitution on structural and electrical properties of La0.8Sr0.2Mn1-xTixO3 (0 ≤ x≤ 0.075) compounds have been investigated. The double exchange interaction mechanism weakens by substituting the nonmagnetic Ti4+ ions in Mn4+ and Mn3+ sites. The results show that with increasing the doping level, metal-insulator transition temperature shifts to lower temperatures and electrical resistivity increases. Also at higher sintering temperature, lattice parameters and unit cell volume increases regularly but resistivity decreases. Electrical resistivity reduction is due to the decreasing of the grain boundary resistivity. Electrical resistivity behavior of samples is in a good agreement with small polaron hopping (SPH) model.In this study, the effect of Ti substitution on structural and electrical properties of La0.8Sr0.2Mn1-xTixO3 (0 ≤ x≤ 0.075) compounds have been investigated. The double exchange interaction mechanism weakens by substituting the nonmagnetic Ti4+ ions in Mn4+ and Mn3+ sites. The results show that with increasing the doping level, metal-insulator transition temperature shifts to lower temperatures and electrical resistivity increases. Also at higher sintering temperature, lattice parameters and unit cell volume increases regularly but resistivity decreases. Electrical resistivity reduction is due to the decreasing of the grain boundary resistivity. Electrical resistivity behavior of samples is in a good agreement with small polaron hopping (SPH) model.https://ijpr.iut.ac.ir/article_845_b86e8d03fe992d1b0e19656875ee557c.pdfThe Physics Society of IranIranian Journal of Physics Research1682-695710120191126Implementation of one-qubit holonomic rotation gate by adiabatic passageImplementation of one-qubit holonomic rotation gate by adiabatic passage1723846FARNader-AliMAmniat-TalabMSaadati-NiariMMir-MehdiJournal Article20191126We propose a robust scheme, using tripod stimulated Raman adiabatic passage, to generate one-qubit rotation gate. In this scheme, a four-level atom interacts with three resonant laser pulses and time evolution of the corresponding coherent system is designed such that the rotation gate is implemented at the end of process. Rotation angle in this gate is holonomic and has a geometrical basis in the parameter space. We also explore the effect of spontaneous emission on the population transfer with numerical solution of Schrödinger and Liouville equations.We propose a robust scheme, using tripod stimulated Raman adiabatic passage, to generate one-qubit rotation gate. In this scheme, a four-level atom interacts with three resonant laser pulses and time evolution of the corresponding coherent system is designed such that the rotation gate is implemented at the end of process. Rotation angle in this gate is holonomic and has a geometrical basis in the parameter space. We also explore the effect of spontaneous emission on the population transfer with numerical solution of Schrödinger and Liouville equations.https://ijpr.iut.ac.ir/article_846_84f7e69969dea92a925508f7c1f9579a.pdfThe Physics Society of IranIranian Journal of Physics Research1682-695710120191126Investigation of the thermal behavior of emission spectra of the doped quantum wells by means of LSE modelInvestigation of the thermal behavior of emission spectra of the doped quantum wells by means of LSE model2533847FAEAbdoliHHaratizadehJournal Article20191126Thermal variation of PL peak energy of undoped nitride semiconductor quantum well shows a successive red-blue-red shifted emission (S-shaped behavior). This behavior has been attributed to the localization of excitons at the energy minima induced by the potential fluctuations in the quantum well structure and/or interface roughness. The S-shaped behavior of PL peak position, the thermal variation of PL line width (FWHM) and the integrated PL intensity as well as the localization exciton have been affected by the modulation doping level. In this paper, exciton localizations of doped and undoped nitride semiconductor quantum wells have been studied by localized states ensembles (LSE) model.Thermal variation of PL peak energy of undoped nitride semiconductor quantum well shows a successive red-blue-red shifted emission (S-shaped behavior). This behavior has been attributed to the localization of excitons at the energy minima induced by the potential fluctuations in the quantum well structure and/or interface roughness. The S-shaped behavior of PL peak position, the thermal variation of PL line width (FWHM) and the integrated PL intensity as well as the localization exciton have been affected by the modulation doping level. In this paper, exciton localizations of doped and undoped nitride semiconductor quantum wells have been studied by localized states ensembles (LSE) model.https://ijpr.iut.ac.ir/article_847_f4552671f8909587cf485ea990207f3b.pdfThe Physics Society of IranIranian Journal of Physics Research1682-695710120191126Ion separation in a Paul trap in the presence of damping forceIon separation in a Paul trap in the presence of damping force3540848FAIZiaeianHNoshadJournal Article20191126Dynamical behavior of particles in a Paul trap has been investigated by solving the set of differential equations considering the effect of damping force. Positions of the trapped ions as a function of time, ion trajectories and the phase space curves in the first stability region have been obtained in the presence of the damping force. The region of stability for r and z components as well as the first stability region with and without the damping force have been computed using the fourth-order Runge-Kutta method. Furthermore, for a Paul trap with specified dimensions and a typical RF frequency, the first stability region for 3H+ and 1H+ ions has been determined in the Vdc – Vac plane. It is worthwhile to note that computation of the stability region in the presence of damping force through the use of this method has been reported for the first time.Dynamical behavior of particles in a Paul trap has been investigated by solving the set of differential equations considering the effect of damping force. Positions of the trapped ions as a function of time, ion trajectories and the phase space curves in the first stability region have been obtained in the presence of the damping force. The region of stability for r and z components as well as the first stability region with and without the damping force have been computed using the fourth-order Runge-Kutta method. Furthermore, for a Paul trap with specified dimensions and a typical RF frequency, the first stability region for 3H+ and 1H+ ions has been determined in the Vdc – Vac plane. It is worthwhile to note that computation of the stability region in the presence of damping force through the use of this method has been reported for the first time.https://ijpr.iut.ac.ir/article_848_362e80d4df43b03ae6d3f8540cd63626.pdfThe Physics Society of IranIranian Journal of Physics Research1682-695710120191126Dissipative in quantum mesoscopic RLC circuitsDissipative in quantum mesoscopic RLC circuits4146849FAHPahlavaniARazmjoJournal Article20191126The quantum theory for a mesoscopic electric circuit with charge discreteness is investigated. Taking the Caldirola-Kanai Hamiltonian in studding quantum mechanics of dissipative systems, we obtain the persistent current and the energy spectrum of a damped quantum LC-design mesoscopic circuit under the influence of a time-dependent external field.The quantum theory for a mesoscopic electric circuit with charge discreteness is investigated. Taking the Caldirola-Kanai Hamiltonian in studding quantum mechanics of dissipative systems, we obtain the persistent current and the energy spectrum of a damped quantum LC-design mesoscopic circuit under the influence of a time-dependent external field.https://ijpr.iut.ac.ir/article_849_fe8c15fed5f808006ce95eddb7366e35.pdfThe Physics Society of IranIranian Journal of Physics Research1682-695710120191126Dependence of Xmax and multiplicity of electron and muon on different high energy interaction modelsDependence of Xmax and multiplicity of electron and muon on different high energy interaction models4753850FAGRastegarzadehMNematiJournal Article20191126Different high energy interaction models are the applied in CORSIKA code to simulate Extensive Air Showers (EAS) generated by Cosmic Rays (CR). In this work the effects of QGSJET01, QGSJETII, DPMJET, SIBYLL models on Xmax and multiplicity of secondary electrons and muons at observation level are studied.Different high energy interaction models are the applied in CORSIKA code to simulate Extensive Air Showers (EAS) generated by Cosmic Rays (CR). In this work the effects of QGSJET01, QGSJETII, DPMJET, SIBYLL models on Xmax and multiplicity of secondary electrons and muons at observation level are studied.https://ijpr.iut.ac.ir/article_850_1efa39bcaec6f3900149160693694536.pdfThe Physics Society of IranIranian Journal of Physics Research1682-695710120191126Investigation of reactivity changes due to flooding the irradiation sites of the MNSR reactor using the MCNP code and comparison with experimental resultsInvestigation of reactivity changes due to flooding the irradiation sites of the MNSR reactor using the MCNP code and comparison with experimental results5561851FAAShiraniHShamoradiIShahabiJournal Article20191126In this work, the Isfahan Miniature Neutron Source Reactor (MNSR ) has been simulated using the MCNP code, and reactivity worth of flooding the inner irradiation sites of this reactor in an accident has been calculated. Also, by inserting polyethylene capsules containing water inside the inner irradiation sites, reactivity changes of this reactor in same such accident have been measured, the results of which are in good agreements with the calculated results. In this work, the reactivity worth due to flooding one inner irradiation site is 0.53mk , and reactivity worth due to flooding of the whole 5 inner irradiation sites is 2.61 mk.In this work, the Isfahan Miniature Neutron Source Reactor (MNSR ) has been simulated using the MCNP code, and reactivity worth of flooding the inner irradiation sites of this reactor in an accident has been calculated. Also, by inserting polyethylene capsules containing water inside the inner irradiation sites, reactivity changes of this reactor in same such accident have been measured, the results of which are in good agreements with the calculated results. In this work, the reactivity worth due to flooding one inner irradiation site is 0.53mk , and reactivity worth due to flooding of the whole 5 inner irradiation sites is 2.61 mk.https://ijpr.iut.ac.ir/article_851_92fb0c6d1758261f10d052e6e2c1123c.pdfThe Physics Society of IranIranian Journal of Physics Research1682-695710120191126Search for supersymmetry in top final states at CMSSearch for supersymmetry in top final states at CMS6363852FANSalimiSPaktinat Mehdiabadi0000-0001-7303-0217Journal Article20191126A search for SUSY using the top quark plus missing transverse energy (MET), in a low mass mSUGRA test point is performed. A two–constraints kinematic fit is utilized to extract the top quark, either b-jet the ones that is recognizable or it is not recognizable. It is shown that for point LM1, for the former situation, a 5σ excess can be achieved with 30 pb-1 and for the latter situation, it can be observed with 9.6 pb-1. The ratio of the final signal over background for both situations is 12.0.A search for SUSY using the top quark plus missing transverse energy (MET), in a low mass mSUGRA test point is performed. A two–constraints kinematic fit is utilized to extract the top quark, either b-jet the ones that is recognizable or it is not recognizable. It is shown that for point LM1, for the former situation, a 5σ excess can be achieved with 30 pb-1 and for the latter situation, it can be observed with 9.6 pb-1. The ratio of the final signal over background for both situations is 12.0.https://ijpr.iut.ac.ir/article_852_22ac3c5a5bf0b520d281c122d1490650.pdfThe Physics Society of IranIranian Journal of Physics Research1682-695710120191126Temperature dependence of I-V characteristics of C60 moleculeTemperature dependence of I-V characteristics of C60 molecule6464853FASAKetabiEMozafariNShahtahmasebiJournal Article20191126Making use of a generalized Green’s function technique and Landauer formalism, the temperature depended current-voltage (I-V) characteristics of C60 molecule, sandwiched between two metallic electrodes are numerically investigated. In addition, the influence of the electron-phonon coupling strength on the electronic properties of the molecule is studied. The I-V characteristics of the molecule are determined in two temperature limits, T=3K and T=300K. Our results indicate that the molecule primarily acts as a semiconductor in lower temperatures but moves toward becoming an ohmic-like conductor when the temperature increased to the higher magnitudes.Making use of a generalized Green’s function technique and Landauer formalism, the temperature depended current-voltage (I-V) characteristics of C60 molecule, sandwiched between two metallic electrodes are numerically investigated. In addition, the influence of the electron-phonon coupling strength on the electronic properties of the molecule is studied. The I-V characteristics of the molecule are determined in two temperature limits, T=3K and T=300K. Our results indicate that the molecule primarily acts as a semiconductor in lower temperatures but moves toward becoming an ohmic-like conductor when the temperature increased to the higher magnitudes.https://ijpr.iut.ac.ir/article_853_aff1621254f7c1be92f64550478c56e6.pdfThe Physics Society of IranIranian Journal of Physics Research1682-695710120191126Pressure effects on Ca60Al40 metallic glass superconductorsPressure effects on Ca60Al40 metallic glass superconductors6565854FAAditya MVoraJournal Article20191126Theoretical computation of the pressure dependence superconducting state parameters of binary Ca60Al40 is reported using model potential formalism. Explicit expressions have been derived for the volume dependence of the electron–phonon coupling strength λ and the Coulomb pseudopotential μ* considering the variation of Fermi momentum KF and Debye temperature ӨD with volume. Well known Ashcroft’s empty core model pseudopotential and five different types of the local field correction functions viz. Hartree, Taylor, Ichimaru-Utsumi, Farid et al. and Sarkar et al. have been used for obtaining pressure dependence of transition temperature TC and the logarithmic volume derivative Ф of the effective interaction strength NOV for metallic glass superconductor. It has been observed that TC of Ca60Al40 metallic glass decreases rapidly with increase of pressure upto 60% decrease of volume, for which the μ* and Ф curves show a linear nature. The superconducting phase disappears at about 60% decrease of volume.Theoretical computation of the pressure dependence superconducting state parameters of binary Ca60Al40 is reported using model potential formalism. Explicit expressions have been derived for the volume dependence of the electron–phonon coupling strength λ and the Coulomb pseudopotential μ* considering the variation of Fermi momentum KF and Debye temperature ӨD with volume. Well known Ashcroft’s empty core model pseudopotential and five different types of the local field correction functions viz. Hartree, Taylor, Ichimaru-Utsumi, Farid et al. and Sarkar et al. have been used for obtaining pressure dependence of transition temperature TC and the logarithmic volume derivative Ф of the effective interaction strength NOV for metallic glass superconductor. It has been observed that TC of Ca60Al40 metallic glass decreases rapidly with increase of pressure upto 60% decrease of volume, for which the μ* and Ф curves show a linear nature. The superconducting phase disappears at about 60% decrease of volume.https://ijpr.iut.ac.ir/article_854_f7e9050c92a851b0016442ab604b0488.pdf