The effect of strain on Thermodynamic properties of tetragonal graphen with considening electron doping

In this thesis, the optical response of quantum dot molecules without and with the presence of metal nanoparticles has been studied. Using the density matrix formalism, the system's behavior is analyzed, and the governing equations of the quantum system are solved in the steady state. By solving the dynamic equations of the system, the linear and nonlinear optical responses have been investigated by calculating the first- and third-order susceptibilities, and the two-photon absorption cross section of quantum dot molecules has been determined. In addition, the phenomenon of induced tra  arency resulting from electron (hole) tunneling between quantum dots in quantum dot molecules has been studied, and the effect of physical parameters such as the tunneling intensity, the energy difference between the energy levels, and the distance between the quantum dot and the metal nanoparticle in a quantum dot molecule system has been investigated. The results obtained can be useful in improving the control of optical properties and designing nanophotonic and optoelectronic structures.

D* meson in the non-relativistic state in the proton-proton collision at the energy of the center of mass ?S=7Tev through the fragmentation of heavy quarks and using the factorization theorem based on the QCD theory of disturbance in hadron colliders We have studied LHC. In this case, after the proton-proton collision,quark c emitted a gluon with spin one and created a quark-antiquark pair, and the desired meson is created from the combination of heavy quark and antiquark. In the first step, calculate the function and the probability of fragmentation for quark c and b in the initial scale of fragmentation. Then, by applying the factorization theorem, we have calculated the differential cross-sectional and the total cross-sectional of ??the production of these particles. And finally, we have studied the behavior of the differential pt

   In this treatise,we investigate the unpolarized transverse momentum dependent (TMD) structure of light nuclei in the modified chiral quark exchange model (QEM), for the first time. To this end, we calculate the TMD quark and gluon distributions inside the bound state nucleons of the light nuclei based on the modified chiral quark model (cQM) in which the TMD bare quark distributions of the bounded nucleons are needed. In order to compute these bare distributions, we first obtain the bare quark momentum densities using the QEM and then calculate the TMD bare distributions applying a theoretical method in which the light-cone variables are used. Finally, considering the nucleon structure of helium, tritium and deuteron nuclei, we obtain their TMD quark and gluon densities at low Q2 scale. Finally, considering the nucleon structure of   14N - 12C -4He - 6Li   uclei, we obtain their TMD quark and gluon densities at low Q2 scale. Due to the unavailability of experimental results for such nuclei, we have examined the general behavior of the obtained distributions. It is shown that our results have appropriate properties that are expected for the TMD distribution functions. Keywords: EMC effect, chiral quark model, quark exchange model, transverse momentum, light nuclei      

ما در اين پژوهش يك روش براي تخمين جهت بردار مغناطيسي بي هنجاري هاي مغناطيسي ارائه ميدهيم.در واقع هدف از تفسير بي هنجاري هاي مغناطيسي ، تعيين موقعيت منابع مغناطيسي است كه باعث پديد آمدن بي هنجاري هايي در ميدان مغناطيسي زمين ميشوند.در نظر گرفتن اين واقعيت كه شكل جانبي و مكان قرار گرفتن بي هنجاري هاي مغناطيسي،نه تنها به مكان و شكل عاملان بي هنجاري ، بلكه به ميدان مغناطيسي زمين و بردار مغناطش منبع مغناطيسي وابسته ميباشد،رسيدن به اين هدف را براي ما دشوار ميكند.روشي كه ما در اين پژوهش براي تخمين جهت مغناطش ارائه ميدهيم مبتني بر داده هاي حاصل از تانسور گراديان مغناطيسي و يكي از تبديل هاي ميدان مغناطيسي بنام تبديل انتقال به قطب است.داده اي كه از تانسور گراديان مغناطيسي حاصل ميشود با نام شدت منبع به هنجار شده شناخته ميشود كه داراي كمترين ميزان وابستگي به بردار مغناطش است.در حالي كه روش هاي رايج مانند بي هنجاري شدت كل ميدان مغناطيسي تا حد قابل توجهي به جهت مغناطش وابسته هستند. اين ويژگي شدت منبع به هنجار شده را به يك پارامتر قابل اطمينان جهت محاسبات مغناطيسي تبديل كرده است.لازم به ذكر است كه شدت منبع به هنجار شده نتايج دقيقي را از مكان منبع مغناطيسي به نمايش ميگذارد.از طرفي فيلتر انتقال به قطب به جهت مغناطش وابسته ميباشد و هنگامي كه جهت هاي صحيح از بردار مغناطش را براي آن استفاده كنيم، بر مكان منبع مغناطيسي متمركز خواهد شد.ما از همبستگي بين داده هاي شدت منبع به هنجار شده و انتقال به قطب براي يافتن جهت مغناطش منبع مورد نظر استفاده ميكنيم.براي يك زاويه ي انحراف و يك زاويه ي ميل،ضريب همبستگي بيشترين مقدار را دارا ميباشد كه آن را به عنوان جهت مغناطش صحيح بي هنجاري مغناطيسي در نظر ميگيريم.ما روش پيشنهادي را براي مدل هاي مغناطيسي مصنوعي ايزوله و متداخل بكار برديم و ميزان خطا را در هر يك از موارد مورد بررسي قرار داديم.و مقايسه اي هر چند اجمالي از شدت منبع به هنجار شده و اندازه ي ميدان كل   بر روي داده هاي حاصل شده به عمل آورديم.و كارايي شدت منبع به هنجار شده و دقت آن را در جهت تعيين مغناطش بي هنجاري به اثبات رسانديم.  

   در كل كار مافرض كرده ايم كه ميدان تورم در معادله حركت در غلتش ثابت قابل قبول است. ما فرض مي كنيم كه تورم با هيچ قشر ديگري همراه نيست بنابراين تورم سرد است. در ادامه كه برسي ما شامل يك مدل تورمي ثابت جديد نيست، اما حاوي يك رويكردي جديد براي بازسازي پتانسيل تورمي كه ثبات تكامل ميدان را ثابت مي كند. به جاي استفاده از ميدان به عنوان متغير، ما از تعدادي عدد توان الكترونيكي استفاده مي كنيم كه به نظر مي رسد يك ابزار مفيد در تورم گرم است. راه حل هاي تحليلي براي پارامترهابل، ميدان اسكالر و پتانسيل به عنوان تابعي از عدد توان الكتذوني، محاسبه شده است. سرانجام، نشان داده شد كه اين روش كاملاً منطبق است بر تحليل راه حل هايي كه تاكنون در تورم   غلتش ثابت به دست آمده است.

In this work, we investigate the optical response of a molecule in an active layer in core-shell and multilayer metallic nanoparticles by calculating its scattering cross section. The molecule in the active layer as a point electric dipole is considered. We also study the effect of an external point charge placed next to the nanoshell on the far-field Raman scattering or fluoresce emission of molecules residing inside the particle. It shown that the presence of an electric charge near plasmonic nanoshells can increase the far-field enhancement. The effect of physical and geometrical parameters on the far-field scattering cross section of the Raman active layer is investigated.

   In this work, we investigate optical nonlinear phenomena up to ninth order of hybrid molecule composed of a semiconductor quantum dot near a spherical metallic nanoparticle (SQD-MNP),and a hybrid nanosystem consisting of   two metallic nanoparticles and a semiconductor quantum dot (MNP-SQD-MNP) in the presence of an external field because for some applications higher-order nonlinearities are desired. On the other hand, by using the density matrix approach, the higher order nonlinear susceptibilities such as third, fifth, seventh and ninth order are obtained. We found that the non-linear optical response of these hybrid systems dependent on the interparticle distance, the size of particle, material of the nanoparticle and the dielectric constant of the inviroment. Also, the higher-order nonlinear refractive indices and absorption coefficient related to the nonlinear susceptibilities are derived and numerically discussed.   

   In this thesis, we have investigated electrical conductivity of bilayer graphene   lattice in two simple and Bernal layouts using spectral distribution function approach. To obtain the electrical conductivity coefficient of the systems , based on the Kubo linear response theory, the electrical conductivity of the systems can be obtained by Fourier transform of the time-dependent current -current correlation function between two current operators at different times. The operating form of the current function can be calculated by means of the charge-current continuity law. To this end, we started from a time-dependent perturbation field and introduced the conductivity coefficient as the linear response of the system to the perturbed electric field. To achieve the desired demand , first the electron tight binding Hamiltonian model, regardless of the kinetic energy effects and the interaction effects between the ions in detail , used to describe the electron dynamics , Then we apply this model for a bilayer graphene lattice considering the effects of the interlayer jump for both simple and Bernal layouts. Then we obtain the Hamiltonian of bilayer graphene lattice in two simple and Bernal layouts for any possible modifications and write the matrices in the Fourier transform matrix in Hilbert space , and after Diagonalizing the resulting Hamiltonian and obtaining the eigenvalues ??of the Hamiltonian matrix, we find the electron energy spectrum. Then, by using the Hamiltonian matrix, the matrix of the retarted Green's function of the system and its density of states can be obtained. Finally, by using the eigenvalues of Hamiltonian matrix , we will obtain the spectral distribution function, Then by placing values ??in the electrical conductivity relation, one can analyze the conductivity coefficient behavior. Common solutions in computational physics can be used to numerically analyze one-dimensional and two-dimensional integrals on the energy and wave vector of the first Brillouin region, that We used the Riemannian and Trapezoidal integration approach here, as well as the Fortran computational and programming software. After performing the necessary numerical calculations, we can discuss the results by drawing the numerical results. We first investigate the behavior of the electrical conductivity coefficient of the system in the first nearest neighbors approximation and the interlayer hopping parametter between the layers for the two simple and Bernal layouts. In addition, the effects of electron jumping to second nearrest neighbors on the physical properties as well as the effects of physical parameters changes in Hamiltonian on the thermodynamic properties of graphene bilayer lattice were thoroughly studied.    Electrical conductivity coefficient Bilayer graphene lattice Simple layout and Bernal layout Spectral distribution function approach

  in this article We investigate the structure of the light nuclei based on the modified chiral quark model (?QM. To this end, we first calculate the parton distribution functions (PDFs) of the bounded nucleons using the ?QM and then compute those of the light nuclei. For this purpose, it is first needed to obtain the bare quark densities inside the bounded nucleons of the nucleus. These bare distributions are calculated by applying the quark exchange model (QEM) in this article. Finally, we obtain the quark, antiquark, and gluon distributions and also the structure functions (SFs) of the bound state nucleons and the light nuclei at low Q2 scale (Q2 = 0.35 GeV2). These distributions can be evolved to the higher scales using DGLAP evolution equations. It is shown that the results of our theoretical framework are in good agreement with the experimental data

This research work reports results of a theoretical study of optical bistability behavior, where  is a typical feature of nonlinear effects, under an external static magnetic field from nanoparticles consisting of  magneto-optical shell and nonlinear metallic core. On the other hand, in this thesis, we study and compare  the magneto-optical properties of plasmonic nanoparticles with spherical and cylinderical geometry in the framework of dipole approximation, because the magneto-optical effect is widely used to manipulate light and  uch nanostructures with magneto-controllable optical bistability  are important to design of  optical nanoswitches, nanosensors.  The impact of the left circularly polarization (LCP) and right circularly polarization (RCP)   on the optical bistability and also the scattering efficiency is shown. In addition to  the influence of the MO effect on the bistable hysteresis and the threshold values, it is demonstrated the bistable behavior is strongly dependent on the incident polarization state.We also study the effect of locality and nonlocality on optical bistability when the core is described by a spatial dispersive dielectric function and the shell is a  magneto-optical material. To investigate the nonlocal effects we assume  the nonlocal response function i  ?(k,?). However, influence of the relevant parameters such as the incident wavelength, the volume fraction , the gyration parameter  g, LCP and RCP incident waves, and the environment on the optical bistability and the scattering coefficient is shown and discussed  

  ‎‎In this research work, the optical bistability, where a nonlinear optical system shows two different values of the local field intensity for one input intensity, in core-shell cylindrical nanoparticles is proposed and investigated within the quasistatic approximation. It is assumed that the core material of the nanoparticle is described by a spatial dispersive dielectric function or the nonlocal response function ‎?(k,?) ‎,coated with Kerr-type nonlinear shell which has a field-dependent permittivity. It is sown that the threshold values and hysteresis loop are adjustable which is important for design of optical bitable devices. However, the effect of the nonlocality, the permeability of the environment, the wavelength of the incoming light on the optical bistability behavior is studied and demonstrated.\\\\In addition to study the nonlocality and nonlocal effects, we investigate the absorption, the transmittance and reflection coefficients of a composite consisting of nanoparticles.   Finally, since graphene decorated nanomaterials can potentially be used in many applications, we study the role of graphene on the optical bistability by considering coated graphene monolayer on the core, shell and core and shell surfaces simultaneously of nanoparticle. It is shown that the optical bistable and the hysteretic behavior is strongly dependent on the Fermi energy of graphene and the carrier relaxation time in graphene

‎In this work‎, the transfer energy between molecules near a spherical multilayer nanoparticle and a coated-graphene nanoparticle is investigated.‎The process of energy transfer from a molecule which called donor to another molecule wich called acceptor has many applications in physics and biology.the most intresting example is the desig n of biosensors based on the energy transfer.‎The donor and acceptor molecules are considered as the point dipole in the vicinity of a plasmonic nanoparticle increases the extend of the energy transfer.‎The effect of parametrs such as the refractive index of the enviroument, the size of nanoparticle,the type of metal,the distance of molecules is shown. also, the influence of the graphene on the transfered energy from the donor molecule to the acceptor molecule is studied.

Based on the laws of 0in 0in 10pt" >Such spatial periodic structures are of two types: ‎ The first type is the macro undulator in a vacuum‎, ‎such as linear magnetic undulator‎. ‎The second one is called crystalline micro undulator (nano micro undulator)‎. ‎The theory of electromagnetic radiation produced by relativistic charged particles moving in nano structures, such as in Carbon nano-tubes is one of the newest areas of the Radiation Physics.   In this Master thesis, ‎the dynamic of motion of relativistic charged particles moving in nano crystalline structures, such as Carbon nano-tubes and produced electromagnetic radiation ‎will be considered. The periodic structure of the Carbon nano tubes will be considered in brief as a device for radiation production. ‎Then‎, ‎according to the periodic structure of the Carbon nanotubes‎, ‎the approximate inter atomic potential taking n into account the thermal vibrations of atoms will be calculated‎. ‎The dynamic of channeling motion will be studied in classical and quantum approximation.   ‎At the end‎, some features of the spectrum of produced radiation will be discussed‎.

In this thesis, the optical properties of the spherical plasmonic nanoparticles and nanoshells is investigated by using tht electromagnetic Maxwell equations. Since the multilayer nanoshells reveales tunable optical charachteristics due to the hybridization of the plasmons of the inner and outer surfaces and also the plasmon-exciton interaction, studying these particles are wothnoting and interesting. The light-velocity slowing factor and the group-velocity dispersion of the nanoshell system having concentric shells around a core consist of different materials such as dielecteric, metal and semiconductor has been studied. The effect of the some pivotal parameters such as size, surrounding medium and composition of shells/core on the slow light   and   the group-velocity dispersion have been demonstrated and analysed. Furtheromre, the transmission probablity, reflection probablity and absorption probablity of a hybride system consist of a composite with embeded spherical nanoparticles and nanoshells (two layer, three layer and four layer)   sandwiched between two metalic parrallel plates has been investigated.  

پس از آزمايش ناكشسان عميق الكترون پروتون SLAC] در سال 1969 تلاش هاي زيادي توسط دانشمندان نظري و تجربي براي بدست آوردن اطلاعات بيشتر در مورد ساختار پارتون­ها [2]   يعني كوارك­هاي ظرفيت، كوارك­هاي دريا و گلئون­ها مربوط به هادرون­  hy;ها و هسته انجام شده است. در بخش تجربي اولين مشاهده در سال 1983 توسط گروه EMC[3] بود. آنها مشاهده كردند كه هنگامي كه هدف از دوتريم به هسته­ي ­سنگين تغيير داده شود اثر قابل توجهي در توابع ساختار نوكلئون­ها ظاهر مي­شود. اما در سال ­هاي اخير بسياري از آزمايش­ها مطالعه­ي خود را روي توابع ساختار هادرون­ها (عمدتا پروتون ونوترون) در xهاي(xمتغير مقياس بيوركن است[4] (كوچك متمركز كرده­اند كه در آنجا كوارك­هاي دريا و گلئون­ها نقش مهمي را بازي مي­كنند. در سال­هاي اخير هم, استفاده از هدف­هاي هليوم سه و تريتيوم غيرقطبيده براي پرتوهاي با انرژي GeV 11 آزمايشگاه جفرسون فراهم شده است . به منظور محاسبه تابع ساختار نوترون از نسبت تابع ساختار هليوم سه و تريتيوم استفاده مي­شود چون، برخلاف پروتون تابع ساختار نوترون را نمي­توان به صورت مستقيم مورد مطالعه قرار داد، بنابراين بايد تابع ساختار آنرا به شيوه­ي غير مستقيم استخراج كنيم. در سال 1986جفي و هدبوي[5] با استفاده از پراكندگي ناكشسان ژرف نسبت تابع ساختار پروتون يا نوترون را در حالت مقيد و آزاد را محاسبه كردند اين انتظار وجود داشت كه، نسبت تابع ساختار حالت مقيد به حالت آزاد برابر يك باشد اما با مشاهده نتايج تجربي و نتايج تئوري و مقايسه آنها ديده شد كه اين نسبت يك نيست. بنابراين به دنبال توجيه اين اختلاف با ارائه مدل­ها و روش­هاي نظري بودند. دلايل مختلفي براي اين تغيير توزيع كواركي داخل نوكلئون­هاي مقيد و آزاد بيان شد كه از جمله مي­توان به اثر فرمي، اثر انرژي بستگي و اثر تبادل كواركي اشاره كرد. در اين پايان نامه بر آن هستيم تا با استفاده از مدل كوارك سازنده سهم كوارك­هاي دريا و گلئون­ها را در توابع ساختار نوكلئون­ها اعمال نموده و انتظار مي­رود كه نتايج اين محاسبات با داده­هاي تجربي به ويژه با داده­هايي كه از آزمايشگاه سرن و جفرسون كه در سال­هاي اخير بدست آمده­اند هم­خواني بهتري داشته باشند.     

در اين پايان نامه پس از مقدمه ي مختصر بر پراكندگي هاي كشسان و ناكشسان رابطه اي براي سطح مقطع ديفرانسيلي پراكندگي ناكشسان الكترون پروتون بدست مي آيد وسپس مدل پارتون و رابطه ي اصلي اين مدل يعني رابطه ي كالان گراس بدست مي آيد اين رابطه به ما اجازه مي دهد كه ر صورت داشتن توابع توزيع پارتون هاي درون نوكلئون بتوان به توابع ساختار آنها دست يافت .

  NiO is a p-type semiconductor with a cubic structure (fcc) and band gap energy between 3.6- 4.0 eV [1-3]. Nano structures of NiO have been reported with various structures such as nanowires [4], nanoplate[5], nanotubes [6] and nano-rings [7].Excellent electronic and optical properties of NiO nano crystalline powder suggest that it could be for using in raw material for p-type tra  arent films, gas sensing units, pollutant clean-up catalysts, alkaline battery cathodes, dye sensitized solar cells and solid oxide fuel cells[8-14]. Various methods exist for synthesis of nickel oxide nanostructures such as sol-gel [15], hydrothermal [16], chemical co-precipitation [17].The NiO nanostructures was synthesized successfully by sol- gel method. Influence of annealing time and annealing temperature and impurity on morphology and structure properties of them studied. The structure parameters (nano crystals size, distance of crystal planes and lattice constant) of prepared samples were determined by XRD analyze. The NiO nanostructures size was increased with increasing annealing temperature, but with annealing time increasing, first decreased and then fixed. The SEM images showed that nanocubes were formed except for the annealing temperature of 300 °C at 24 h.

  Tin oxide nanostructures because of stability in weather conditions, chemical kinetic, mechanical hardness and resistance to high temperature has caused the most popular among the oxide transparent conductive oxides are  available.In this paper Tin Oxide Nanostructures Doped With Zinc Atoms layer chemical preparation method we want to. The nano-structure on a glass substrate using  alt  As a precursor and  Z  alt  As we prepare to impurities and physical properties such as optical properties in different circumstances, which may include absorption spectrum and energy gap and examine structural properties such as the formation of crystal growth

In recent years, much attentions have been paid to the metal-semiconductor nanostructures due to their potential applications in science and technology, and also in enhancing the nanoscale sensors and optical devices. In addition, the exciton-plasmon interactions makes them a hot topic in the field of nanoscience and plasmonics. Interaction ‎between ‎noble ‎metal ‎plasmons ‎and ‎semiconductor ‎exciton‎s could lead to interesting nonlinear optical effects such as electromagnetically induced tra  arency (EIT) and slow light. Moreover, this phenomena would open a new route for designing new optical sensors and devices based on plasmon-exciton interaction. In this study, the electrodynamic of concentric cylindrical nanoshells in the framework of the Mie formalism has been investigated theoretically . By introducing the TE and TM modes in cylindrical geometry, the scattering coefficients for core-shell and multishell nanoparticles has been calculated. By considering an effective dielectric function for the system and using the Clausius-Mossoti relation, the group velocity in the medium has been formulated. Furthermore, the induced electromagnetic tra  arency in a system consisting of a dielectric slab doped with cylindrical nanoparticles sandwiched between two metallic parallel plates has been investigated.The influence of some key parameters such as the thickness of layers, the size and composition of nanoparticles and slabs on EIT has been shown and analyzed.

  در اين پايان­نامه ما در ابتدا به معرفي پروژه برخورددهنده بزرگ هادرون-الكتروني پرداخته و سپس با معرفي مدل استاندارد فيزيك ذرات و جدول ذرات بنيادي، در مورد اهميت و خواص و نيز نحوه توليد كوارك سر به عنوان سنگين­ترين ذره بنيادي شناخته شده در طبيعت با استفاده از نتايج آزمايشگاهي صحبت خواهيم كرد. در محاسبات نظري، كوارك سر به دليل جفت شدگي بسيار زيادي كه با بوزون هيگز دارد مورد بسيار خوبي جهت تحقيق در حيطه فيزيك هيگز مي­باشد. به همين دليل در اين كار ما به جستجو و تعيين سطح مقطع براي جفت شدگي كوارك-پادكوارك سر و بوزن هيگز در فرآيند پراكندگي ناكشسان عميق الكترون-پروتون در برخورددهنده بزرگ هادرون-الكتروني پرداختيم. فرآيند مورد نظر ما كه از پراكندگي ناكشسان عميق بين الكترون و پروتون سر چشمه مي­گيرد، به وسيله فوتون مجازي منتشر شده از الكترون و نيز گلوئون ساتع شده از پروتون انجام مي­شود كه به اين فرآيند همجوشي بوزون-گلوئون مي­گوييم. نتيجه محاسبات ما با استفاده از پتانسيل عظيم به وجود آمده در برخورددهنده بزرگ هادرون-الكتروني مي­باشد به اين دليل كه برخورددهنده­هاي لپتون-هادروني نسل قبل انرژي لازم براي توليد اين ذره سنگين را نداشتند. در نهايت ما نتيجه بدست آمده از سطح مقطع مربوط به جفت­شدگي كوارك-پادكوارك سر و هيگز را با نتايج موجود در برخوردهاي هادرون-هادروني و همجوشي گلوئون-گلوئون مقايسه كرده و بيان مي­كنيم كه هرچند سطح مقطع اين فرآيند از طريق همجوشي بوزون-گلوئون كمتر است اما دقت محاسبات براي شناخت فيزيك هيگز بسيار دقيق­تر خواهد بود.

  Nickel oxide thin films use in the fabrication of electric anode, because of the high electronic efficiency and high of stability, durability, and conductivity. In this study, thin films of zinc doped nickel oxide (Zn@NiO) are prepared by Radio-frequency (RF) magnetron sputtering technique and these films are deposited on glass substrates at room temperature. The influence of various surface area percentage of Zn/Ni; 0, 2, 4, 8 and 16% (named as 0ZNO, 2ZNO, 4ZNO, 8ZNO and 16ZNO); and annealing temperatures on the structural, morphology and optical properties of the deposited thin films, are investigated. These parameters are determined by UV-Vis, XRD, AFM and SEM analysis. It is observed that with the increase of the annealing temperatures, a growth mode transformation appears from island growth to layer growth. XRD studies showed by doping Zn, intensity of the (111) plane decrease which indicates losing crystallite quality. The optical band gap of NiO thin film decreases with doping of Zn (3.45 to 3.00). Doping process led to the emergence of localized levels in area between valence band and conduction band.