Gravitational backreaction effect of Schwinger pair production in a strong electric field in de Sitter spacetime
Ehsan
Bavarsad
Department of Physics, University of Kashan, Kashan, Iran
author
Narbeh
Margosian
Department of Physics, University of Kashan, Kashan, Iran
author
text
article
2018
per
In this paper, a massive charged scalar field in a uniform strong electric field background in a de Sitter spacetime of arbitrary dimension has been considered. Using Bogoliubov coefficients, we obtain the semiclassical energy-momentum tensor of the Schwinger pairs in the strong electric field limit. We have shown that the trace of the semiclassical energy-momentum tensor vanishes. We have found that the nonvanishing components of the semiclassical energy-momentum tensor increase by a power of the electric field. Our results of the semiclassical energy-momentum tensor would be important for discussing the gravitational backreaction effect of the Schwinger pair production. We have shown that the Hubble constant decays and the time scale of the decay decreases by a power of the electric field.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
8
v.
17
no.
2018
1
10
http://jrmbs.scu.ac.ir/article_13879_c837b5ab4b86d4d02294d6e41527a3a2.pdf
dx.doi.org/10.22055/jrmbs.2018.13879
Synthesis of MnS nanoparticles and effect of growth parameters on the optical properties
Bahareh
Ghanbari
Department of Physics, Science and Research Branch, Islamic Azad University, Ahvaz, Iran
Department of Physics, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran
author
Farid
Jamali-sheini
Department of Physics, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran
author
Ramin
Yousefi
Department of Physics, Masjed-Soleiman Branch, Islamic Azad University (I.A.U), Masjed-Soleiman, Iran
author
text
article
2018
per
In this research, hydrothermal-microwave process was used for synthesis of manganese sulfide (MnS) nanoparticles (NPs). The effects of growth parameters such as concentration, solution type, and power were investigated. After synthesis, different thermo-radiations of microwave were applied and optical properties were studied. Different characterization methods for study of NPs properties such as X-ray diffraction (XRD), transmission and scanning electron microscopy (TEM and SEM), energy dispersive X-ray, and UV-Visible spectroscopy were used. XRD patterns and EDS spectra represent formation of polycrystalline MnS phase and the existence of desired elements, respectively. Electron microscopy images showed the composition of NPs in the form of adherent spherical particles. With increasing in synthesis temperature, optical energy band gap increased and relative absorbance intensity decreased.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
8
v.
17
no.
2018
11
18
http://jrmbs.scu.ac.ir/article_13880_7c26c75efcc07388f6bbfccadddbb387.pdf
dx.doi.org/10.22055/jrmbs.2018.13880
Study of effect correlated noise in tumor growth using extensive and non-extensive entropy
رضا
خرداد
هیات علمی
author
حمید رضا
رستگار سدهی
هیات علمی
author
text
article
2018
per
It is to be noted that tumor growth has been studied by additive and multiplicative noise. These methods can be often employed as discrete procedures or they can be depended. In this paper, the tumor growth has been investigated using three different entropy models. We have calculated the steady state probability distribution function using Plank-Fokker equation. The obtained results show that the variations of intensity of the multiplicative and additive noises lead to the tumor cells growth. Also, the tumor cells growth can be controlled by changing the non-extensive degree. The growth of tumor cells increase with enhancing the correlated noises.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
8
v.
17
no.
2018
19
29
http://jrmbs.scu.ac.ir/article_13881_e96ad4f80f458a3e5cf1eebc9bbab537.pdf
dx.doi.org/10.22055/jrmbs.2018.13881
Investigation on UHECR Interactions with cosmic background photons using CRPropa 3.0
گوهر
رستگارزاده
هیأت علمی / دانشگاه سمنان
author
Hajar
Fallahnejad
Physics department, semnan university, semnan, iran
author
text
article
2018
per
In this paper using simulation code CRPropa3.0, the propagation of 104 primary cosmic rays of proton and iron with energy range of 1018 to 1021 eV have been simulated. The spectra of the secondary photons and electron- positrons generated in the interactions of ultra- high energy cosmic rays (UHECRs) with cosmic background photons are investigated. The photon and electron spectra considered here are generated in photopion production, beta decay, and pair production. The minimum energy of primaries and the spectral index of source injection is changed separately and the effect of these changes on the spectra is investigated. Also, the total primary energy percent which transfers to secondaries, is calculated. It is found that for both primaries, lowering the minimum energy of the primaries, causes decreasing of the secondaries flux, this also results to the decrease of the total energy percent carried by beta and photopion products and the increase of the energy percent of pair production. Finally, in is shown that by increasing the spectral index, the flux and the energy percent of all scondaries decreases for proton and iron primaries.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
8
v.
17
no.
2018
31
39
http://jrmbs.scu.ac.ir/article_13882_b99176b90262617f09cd6a680f9edbec.pdf
dx.doi.org/10.22055/jrmbs.2018.13882
The effect of neutron matter equation of state on the distribution of dark matter in neutron star
زینب
رضایی
هیئت علمی
author
text
article
2018
per
In this paper, we investigate the effect of neutron matter equation of state on the structure of halo of dark matter and the distribution of dark matter in neutron star using the relativistic two-fluid formalism in the dark-matter admixed neutron star. Applying the equation of state related to the free fermionic gas as dark matter equation of state, we calculate the structure of dark-matter admixed neutron star within different models of Skyrme interaction for the neutron matter, SLy230a, SLy230b, SkM*. Our results indicate that the mass-radius relation depends on the model of interaction. In addition, our calculations confirm that the neutron matter equation of state affects the size of dark matter and neutron matter cores. The results show that the surface gravitational redshift depends on the neutron matter equation of state.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
8
v.
17
no.
2018
41
50
http://jrmbs.scu.ac.ir/article_13883_84a61f30b73da8dbf3ac2786da49a1e4.pdf
dx.doi.org/10.22055/jrmbs.2018.13883
Analysis of the Three-dimensional time-dependent Schrödinger equation by the meshless local Petrov- Galerkin method
Mohamma Javad
Mahmoodabadi
Department of Mechanical Engineering, Sirjan University of Technology
author
Farideh
Shojaei
هیئت علمی
author
Zahra
Arasteh
Faculty of Physics, University of Shahid bahonar Kerman.
author
text
article
2018
per
In this paper, the meshless local Petrov-Galerkin (MLPG) method is presented for the numerical solution of the three-dimensional time-dependent Schrödinger equation. The method is based on the local weak form and the moving least squares (MLS) approximation. In this paper, the Heaviside step function is regarded as the test function. Local sub-domains are also considered as cubic shapes. In order to satisfy the essential boundary conditions, the penalty parameter technique is implemented due to the MLS approximation can’t satisfy Kroniker delta function property. The forward finite difference method is used to decompose the time expression of Schrödinger equations. Moreover, the MLPG results of the problem are compared with those obtained by an exact analytical solution which shows the efﬁciency and accuracy of this method.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
8
v.
17
no.
2018
51
58
http://jrmbs.scu.ac.ir/article_13884_77be860b373fe84ac7b8c2cb0e22ba43.pdf
dx.doi.org/10.22055/jrmbs.2018.13884
Synthesis of ZnS:Mn Nanoparticles And Investigaton of Its Ability to Produce Reactive Oxygen Species
ehsan
sadeghi
university of kashan
author
mostafa
zahedifar
null
author
zahra
mahmoodian
university of kashan
author
text
article
2018
per
Today, semiconductor nanoparticles have attracted much attention in nano-medicine branches. In this study, the ability of the ZnS:Mn nanoparticles to produce reactive oxygen species including radical hydroxyl were investigated and also preparation method of these nanoparticles was reported. ZnS:Mn nanoparticles were synthesized using co-precipitation method. Excitation of nanoparticles was done by UV radiation. The formation and structure of nanostructures was investigated by XRD, SEM and PL analysis. The PL emission spectrum of the ZnS:Mn nanoparticles shows two main peaks in wavelength of 444 and 587 nm. The size of ZnS:Mn nanoparticles was obtained at about 24 nm using XRD result which it is in agreement to SEM and TEM images. According to the decrease in absorption intensity of methylene blue detector in irradiation alongside prepared nanoparticles, it can be said that ZnS:Mn nanoparticles are able to create hydroxyl radicals. This suggests that ZnS:Mn nanoparticles can be used to cancer therapy in photodynamic therapy method.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
8
v.
17
no.
2018
59
65
http://jrmbs.scu.ac.ir/article_13885_4a8f59a9a349f151ad4172abfc9967ae.pdf
dx.doi.org/10.22055/jrmbs.2018.13885
Solutions of Reactor Point Kinetics equations with six group of delayed neutrons using Collocation method
masoud
seidi
faculty of ilam university
author
parviz
darania
Department of mathematics, Faculty of Science, Urmia University, P.O.Box:165-57153, Urmia –
Iran
author
saeid
pishbin
Department of mathematics, Faculty of Science, Urmia University, P.O.Box:165-57153, Urmia –
Iran
author
text
article
2018
per
In this study we have used Collocation Method (COM) as a new method in the control and dynamics of reactor fields for solution of reactor point kinetics equations in the presence of step, linear and sinusoidal reactivities with six groups delayed neutron. The calculation code has written by MATHEMATICA software. This method in addition to the low time of calculations and convergence of solutions, it has high accuracy. The results of numerical calculations by COM compared with other numerical methods show that this method is efficient and accurate. Therefore, it can be used for dynamical computing at the startup stage of the reactor.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
8
v.
17
no.
2018
67
75
http://jrmbs.scu.ac.ir/article_13886_0a81d8ab6c527306be2bb7f1168c06f6.pdf
dx.doi.org/10.22055/jrmbs.2018.13886
The effect of magnetic field generated by the interaction of high-intensity laser pulse and low-density plasma on electron bunch acceleration in the bubble regime
مهدی
عصری
عضو هیئت علمی
author
text
article
2018
per
In this paper, the effect of the magnetic field generated by the interaction of femtosecond high-intensity laser with under-dense plasma in the bubble regime on the acceleration of an electron bunch with Gaussian distribution in velocity and position has been studied. It was seen that the magnetic field could increase the final energy of electron bunch from about 1 GeV to approximately 1.2 GeV and reduces the final energy spread. Also, the final emittance of electron bunch decreased about one order of magnitude and it has been equal to 0.38 * 10^-3 mm mrad. Moreover, we observed that the magnetic field caused ten percent increment in number of accelerated electrons.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
8
v.
17
no.
2018
77
86
http://jrmbs.scu.ac.ir/article_13887_78b84ea3e060c370eaec88bbd412e567.pdf
dx.doi.org/10.22055/jrmbs.2018.13887
Investigation of the electron distribution function Effect on the Collisional Absorption in laser- driven fusion
leila
gholamzadeh
Nuclear Group, faculty of physics, Yazd University, Yazd, Iran
author
text
article
2018
per
Inertial confinement fusion is driven by laser or heavy ion beams. In the laser driven- fusion, one of the important points is to absorb laser energy as much as possible. Collisional absorption is an essential mechanism for absorption of laser energy into the target in the critical surface. In this paper, using kinetic theory, the collisional absorption is theoretically studied in an unmagnified and uniform plasma. Collisional absorption is compared for two different one-dimensional Maxwellian and q non-extensive distribution functions and linearly polarized light laser. Our results show that higher absorption is obtained for q non-extensive distribution function and this difference will be more with increasing of q value. Also, the effect of the Coulomb logarithm and laser wavelength are considered on the collisional absorption coefficient. The absorption value will decrease with increasing of the laser wavelength and also the Coulomb logarithm value has direct relation with the absorption value of energy.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
8
v.
17
no.
2018
87
94
http://jrmbs.scu.ac.ir/article_13888_56958f3a2879e6198f35cc413ab0b64f.pdf
dx.doi.org/10.22055/jrmbs.2018.13888
Ab initio calculations of structural, phonon and thermal properties of Co2MnGe and Co2MnSi
ali
fazeli kisomi
دانشگاه آزاد اسلامی اردبیل
author
Seyed Javad
Mousavi
Assistant Professor Of Physics,Department Of Physics, Rasht Branch, Islamic Azad University, Rasht, Iran
author
text
article
2018
per
In this paper, structural, phonon and thermal properties of Co2MnGe and Co2MnSi calculated and have been compared with each other. Structural properties of these alloys have a good agreement with other experimental and theoretical works. By using density functional perturbation theory and Quantum Espresso package, phonon dispersion calculation in different directions have been done. Calculation of total and partial phonon density of states demonstrated that by increasing of mass of atoms their contributions decrease at higher frequencies. Also, calculations of specific heat at constant volume and Debye temperature by quasi-harmonic Debye-Einstein model and GIBBS2 package have been performed by considering only phonon contribution in the temperatures range of 0K to 900K which have a good consistency with other theoretical works. Specific heat at low temperatures has T3 behavior, while it trend to saturation limit at high temperatures. Debye temperature decrease by increasing temperature slowly.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
8
v.
17
no.
2018
95
102
http://jrmbs.scu.ac.ir/article_13889_fa2db0800d2a5968e1ba4b11fcc0fc8e.pdf
dx.doi.org/10.22055/jrmbs.2018.13889
Intra-molecular magnetic coupling pathways in the magnetic molecule tripyridinium bis[tetrachloroferrate(III)] chloride via analysis of density of states (DOS)
Mohammad Bagher
Fathi
Condensed Matter Dep., Faculty of Physics, Kharazmi University, Tehran, Iran
author
Niloofar
Kamalkhani
Condensed Matter Dep., Faculty of Physics, Kharazmi University, Tehran, Iran
author
text
article
2018
per
The electronic charge transfer between the magnetic sites is essential for controllability of the magnetic molecules. Through an analytical study of the density of states (DOS) of the different parts of magnetic molecule [py.H]3[FeCl4]2Cl, the electronic transitions corresponding to the induced magnetization curve under the irradiation of light (Faraday rotation), we illustrate the plausible intra-molecular superexchange pathways inside the molecule. A qualitative justification of large superexchange seen previously in the molecule is addressed by employing a method for deciding the plausible pathway for magnetic coupling between magnetic centers. Results of the present work justify the previous theoretical predictions made in previous works making use of different graphical methods.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
8
v.
17
no.
2018
103
111
http://jrmbs.scu.ac.ir/article_13890_2bb1cf0a664c90c505601a15a25e60ae.pdf
dx.doi.org/10.22055/jrmbs.2018.13890
Production of CNTs fibers by wet spinning method and investigation of their physical properties
Mansour
Farbod
Department of Physics, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran
author
Sanaz
bigdeli
Department of Physics, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran
author
Abdol Mohammad
Ghalambor Dezfuli
Department of Physics, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran
author
text
article
2018
per
In this work PVA / MWCNT composite fibers were produced by a wet spinning method. In order to fabricate the fibers, first carbon nanotubes were dispersed in deionized water using sodium dodecyl sulfate (SDS) surfactant. Using UV-vis analysis, the highly dispersion of carbon nanotubes was confirmed. Such solution was mixed homogenously in an aqueous solution of PVA and then was injected into PVA and Na2SO4 static coagulation baths. The resulting fibers were uniform and homogeneous in diameter and could be spun out indefinitely. The structure of the fibers was syudied by SEM and their strength was investigated using an Instrom tensile tester.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
8
v.
17
no.
2018
113
122
http://jrmbs.scu.ac.ir/article_13891_38b82dd1218dda214830dd57bf7f4d9d.pdf
dx.doi.org/10.22055/jrmbs.2018.13891
Designing and optimization of perovskite solar cells using different electron-transporting materials
Elham
Karimi
Department of Physics, University of Kashan, Khashan, Iran
author
S.M. Bagher
Ghorashi
Department of Physics, University of Kashan, Khashan, Iran
author
text
article
2018
per
Abstract This paper presents a comparative study of organometal halide perovskite-based solar cells using two different transparent conducting oxides, including SnO2 and ZnO, as electron-transporting materials. Simulation is an interesting way of studying the behavior of every component of a solar cell device as well as analyzing the performance of the full device. A solar cell capacitance simulator (AMPS)-1D has been the tool used for numerical simulation of such devices. In this study, the inluences of thickness of absorber and ETMs, dopant concentration of absorber and ETM, and working temperature on the performance of photovoltaic solar cells are studied. The performance of both devices indicates the replacement of SnO2 by a ZnO layer. ZnO can be a good option to reduce the cost and increase the mobility of ETM for this type of solar cells.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
8
v.
17
no.
2018
123
133
http://jrmbs.scu.ac.ir/article_13893_5a9f566555f216ebb40775a529ff57c7.pdf
dx.doi.org/10.22055/jrmbs.2018.13893
Calculating the ground state entanglement of a two-dimensional spin star lattice
صغرا
قنواتی
هیات علمی
author
مجتبی
جعفرپور
هیات علمی
author
text
article
2018
per
In this study, the ground states of a 6-qubit star lattice are studied in the presence of a magnetic field. In addition, their bipartite and multipartite entanglements are obtained, using concurrence as a measure of bipartite entanglement and Meyer–Wallach measure and its generalizations as the measures of multipartite entanglement. Also a comprehensive structure of their entanglement is presented and described. It is shown that the external magnetic field is a tuning agent that determines the separable ground states, the global entangled states and the states between them. Determination of these states helps to choose the required ones, for different quantum information processes.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
8
v.
17
no.
2018
135
143
http://jrmbs.scu.ac.ir/article_13894_00b469fde91d09ad613451856e9c046d.pdf
dx.doi.org/10.22055/jrmbs.2018.13894
Spin conductivity of gapped graphene
saeed
marvi
Department of Physics , Faculty of Science, Malayer, Iran
author
rostam
moradian
Faculty member of kermanshah university
author
Hamed
Rezania
faculty member of kermanshah razi university
author
text
article
2018
per
Spin conductivity of gapped graphene using Hubbard model is calculated. We obtain spin conductivity for two cases, the first we ignore coulomb interaction between electrons and the second in presence of coulomb interaction between electrons. It can be seen that for nonitercting case, by increasing the energy gap and magnetization, the spin conductivity in a constant frequency is increased. In interacting case plots of spin conductivity versus frequency have two peaks. One of them belongs to spin up electrons and the other belongs to spin down electrons. By increasing magnetization the peaks of spin up electrons will be shifted towards lower frequencies and the peaks of spin down electrons will be shifted towards higher frequencies. By increasing the repulsion coulomb interaction and the energy gap, spin up and spin down peaks will be shifted towards higher frequencies.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
8
v.
17
no.
2018
145
155
http://jrmbs.scu.ac.ir/article_13895_4051b6b0dee687ce19e42e98d5923503.pdf
dx.doi.org/10.22055/jrmbs.2018.13895
Calculation of Reaction rate and astrophysical S-Factor for 16O (p, γ) 17F Reaction
Ali
Moghadasi
Physics Department of Arak University
author
Hossein
Sadeghi
Department of Physics
author
Reza
Pouimani
Department of Physics, Arak University
author
text
article
2018
per
The 16O(p,γ)17F reaction is an important reaction in CNO cycle and effective in the stellar revolution. The Cross Section and S-Factor calculated with using woods Saxon potential for bound levels including 5/2+( ground state) and 1/2+ (first excited state). The main portion of the total cross section for both final states is provided by E1 transitions from the incoming p wave to the bound 1d5/2 and 2s1/2 states. It is clear that contribution of S- Factor in the ground state because of deeply bound state and higher angular momentum lesser than the contribution of first excited state and the halo properties of the proton at 1/2+ state. By comparing our results with the previous results, a good agreement observed. S-Factor at zero Energy for states 5/2+ and 1/2+ calculated 0.3482 and 10.21 (keV.b), respectively. Also, we calculated reaction rate, which seen good agreement between our results and NACRE & CA88 data.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
8
v.
17
no.
2018
157
165
http://jrmbs.scu.ac.ir/article_13896_4f031152d8caf44ad9530095b2dd3d2b.pdf
dx.doi.org/10.22055/jrmbs.2018.13896
Investigation of sintering time on structural, magnetic and dielectric properties strontium spinel ferrite nanoparticles (SrFe2O4) synthesized by sol-gel method
ٍٍSeyed Ebrahim
Mousavi Ghahfarokhi
Department of physics, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran
author
Elham
Mohammadzadeh Shobegar
Department of physics, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran
author
Morteza
Zargar Shoushtari
Department of physics, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran
author
text
article
2018
per
In this paper, strontium spinel ferrite (SrFe2O4) nanoparticles were prepared by sol-gel method. Also, in order to the effect of sintering time on the structural, magnetic and dielectric properties of SrFe2O4 nanoparticles, first, the gel of the metal nitrates with certain molar ratio prepared and then the prepared powders were calcined at 700 ℃ with different times. The results of XRD show that the main phase of SrFe2O4 increase by increasing sintering times. Also, the FESEM images of the samples show that the particles of SrFe2O4 are homogeneous, but as the samples have magnetic properties, thus agglomeration of them have been occurred. The results of the samples FT-IR show that the sites of tetrahedral and octahedral which are important properties of ferrites were formed. The magnetic properties of the samples show that by increasing the sintering time, the amount of Ms and Hc has been increased which these changes are due to the distribution of ions and shape anisotropy of the nanoparticles. The results of the measurements of dielectric of the samples show that the both ε and for the samples decrease rapidly with increasing applied field frequency, while the ac electrical conductivity has been increased.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
8
v.
17
no.
2018
167
180
http://jrmbs.scu.ac.ir/article_13897_895e08231656a61704dfdbd834a1f538.pdf
dx.doi.org/10.22055/jrmbs.2018.13897
Super Quantum Discord Behaviors in Two-Qubit Heisenberg XYZ Model with Intrinsic Decoherence
Forouzan
Mirmasoudi
Department of Physics, University of Mohaghegh Ardabili, Ardabil
author
Sodeif
Ahadpour
Department of Physics, University of Mohaghegh Ardabili, Ardabil
author
text
article
2018
per
In this paper, dynamics of super-quantum discord in Heisenberg model that has Dzyaloshinskii-Moriya interaction, we will study the influence of environmental decoherence by taking Lyndblad equation. We consider Werner state as the initial state of the system. By calculating the time evolution of the system, we figure out the influence of mixture degree r on the dynamics such as super quantum discord, quantum discord and cancurrence. A remarkable result is that when the initial state is Bell state the concurrence decays from 1 to a minimum value close to 0 but the super-quantum discord and quantum discord vanish. This is contrary to recent results obtained. The effect of coupling between the quantum system and environment on super-quantum discord based on interaction parameters. The results show that the magnitude of Dzyaloshinskii-Moriya interaction that represents the interaction of spin-orbit interaction, has played a significant role the amount of super quantum discord.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
8
v.
17
no.
2018
181
189
http://jrmbs.scu.ac.ir/article_13898_688639ede3dc80d90b00b3bbc8c247b1.pdf
dx.doi.org/10.22055/jrmbs.2018.13898
Comparative Analysis of the Static and Dynamic Performances of Quantum-Dot lasers and Quantum Cascade Lasers Using Rate Equations Model
Hossein Reza
Yousefvand
Electrical Deptment, Faculty of Engineering, Islamic Azad University, Islamshahr Branch, Tehran, Iran.
author
text
article
2018
per
In this paper, the static and dynamic performances of quantum-dot (QD) semiconductor lasers and quantum cascade (QC) lasers are characterized and analyzed comparatively using the standard rate equations model. Using the presented model, the effect of photon lifetime on both the device’s output characteristics is investigated. Simulated results show that due to the ultrafast nature of intersubband transitions (ISTs) in QC lasers that dominantly induced by the longitudinal optical (LO) phonon emission with a picosecond time scale, the threshold current in QC lasers are much larger than is common for QD lasers, in which the intrinsic carrier lifetime is on the order of a few nanoseconds due to the nature of band-to-band Auger recombination process. Additionally, since the LO-phonon scattering process in QC lasers is an ultra-fast mechanism, transient oscillations of the photon density are overdamped, and no resonance appears in the frequency response. This is in contrast with the transient oscillations and frequency response of QD lasers. For comparison, this unique feature makes QC lasers ideally suited for high-speed operation.
Journal of Research on Many-body Systems
Regional Information Center for Science and Technology (RICeST)
2322-231X
8
v.
17
no.
2018
191
203
http://jrmbs.scu.ac.ir/article_13899_7c748f9aab66e08a6d609e4e165b5f72.pdf
dx.doi.org/10.22055/jrmbs.2018.13899