The Experts below are selected from a list of 225 Experts worldwide ranked by ideXlab platform
K Jayakumar - One of the best experts on this subject based on the ideXlab platform.
-
impurity states and Diamagnetic Susceptibility of a donor in a triangular quantum well
AIP Conference Proceedings, 2017Co-Authors: P Kalpana, P Nithiananthi, Merwyn Jasper A D Reuben, K JayakumarAbstract:We have calculated the binding energy and the Diamagnetic Susceptibility(χdia) of the ground (1s) and few low lying excited states (2s and 2p±) in a GaAs/AlxGa1-xAs Triangular Quantum Well (TQW) for the Al composition of x = 0.3. Since the estimation of gives the carrier localization in nanostructured systems and also the calculation of (χdia) involves the , the same has also been estimated as a function of well width. The Schrodinger equation has been solved using variational technique involving Airy functions in the effective mass approximation. The results are presented and discussed.
-
the Diamagnetic Susceptibility of a donor in a semiconductor core shell quantum dot
SOLID STATE PHYSICS: Proceedings of the 59th DAE Solid State Physics Symposium#N#2014, 2015Co-Authors: M S Sudharshan, K Jayakumar, P Subhash, Nagoor Babu Shaik, P Kalpana, Merwyn Jasper A D ReubenAbstract:The effect of Aluminium concentration, shell thickness and size of the core shell Quantum Dot on the Diamagnetic Susceptibility of a donor in the Core Shell Quantum Dot is calculated in the effective mass approximation using the variational method. The results are presented and discussed.
-
Diamagnetic Susceptibility of a hydrogenic donor in a quantum dot
Physica Status Solidi B-basic Solid State Physics, 2006Co-Authors: Merwyn Jasper A D Reuben, K JayakumarAbstract:We investigate within the effective mass theory, the influence of the shape of the confining potential and the geometry of the Quantum Dot on the Diamagnetic Susceptibility Χ dia of a hydrogenic donor using variational method. We compare Χ dia of a donor in a Spherical Quantum Dot for both infinite and finite barrier model. The effect of the location of the donor and Al composition x of the Al x Ga 1-x As barrier of the Quantum Dot is also studied.
-
Diamagnetic Susceptibility of hydrogenic donor impurity in low dimensional semiconducting systems
Solid State Communications, 2006Co-Authors: P Nithiananthi, K JayakumarAbstract:Abstract The binding energies of a hydrogenic donor both in the parabolic and non-parabolic conduction band model within the effective mass approximation have been computed for the low-dimensional semiconducting systems (LDSS) like quantum well, quantum well wire and quantum dot taking GaAs/Al x Ga 1− x As systems as an example. It is observed that the effect of non-parabolicity is not effective when the system goes to lower dimensionality. The Diamagnetic Susceptibility of a hydrogenic donor impurity has also been computed in these LDSS in the infinite barrier model. Since no theoretical or experimental works on the Diamagnetic Susceptibility of LDSS are available in the literature, as a realistic case the Diamagnetic Susceptibility has been computed in the finite barrier model ( x =0.3) for a quantum well and the results are discussed in the light of semiconductor–metal transition.
R Khordad - One of the best experts on this subject based on the ideXlab platform.
-
energy gap renormalization and Diamagnetic Susceptibility in quantum wires with different cross sectional shape
Journal of Computational Electronics, 2016Co-Authors: Zakieh Avazzadeh, H Bahramiyan, R Khordad, Seyyed Abbas MohammadiAbstract:In this study, we investigate the effect of the cross-sectional shape on the energy gap renormalization and Diamagnetic Susceptibility in various quantum wires. To this end, we consider quantum wires with different cross-sectional shapes such as circular, square, hexagonal, and triangular. First, we employ the finite-element method and Arnoldi algorithm to solve the Schrodinger equation. Then, we calculate the energy levels, wavefunctions, binding energy, energy gap renormalization, and Diamagnetic Susceptibility. Our numerical results show that the binding energy decreases when the cross-sectional area is increased for all the quantum wires. Moreover, it is inferred that the cross-sectional shape is not important for large cross-sectional area when calculating the binding energy. Indeed, the main parameter is the cross-sectional area rather than the length of a side. The energy gap renormalization decreases with increasing cross-sectional area, regardless of the impurity concentration. We observe that the highest and lowest energy gap renormalization correspond to triangular and circular quantum wires, respectively. The absolute value of the Diamagnetic Susceptibility increases with increasing cross-sectional area for all the quantum wires investigated.
-
Diamagnetic Susceptibility of an off center hydrogenic donor in pyramid like and cone like quantum dots
European Physical Journal Plus, 2016Co-Authors: Zakieh Avazzadeh, H Bahramiyan, R Khordad, Seyyed Abbas MohammadiAbstract:In this study, the Diamagnetic Susceptibility of an off-center hydrogenic donor impurity confined by pyramid and cone-like quantum dots has been investigated. To this end, the finite-element method and the Arnoldi algorithm are used to find energy eigenvalues and eigenvectors of the systems. Then, the effect of impurity position and dot size has been investigated on the Diamagnetic Susceptibility. We have found that the Diamagnetic Susceptibility has a maximum around the impurity position 4nm for two quantum dots. The Diamagnetic Susceptibility in the cone-like quantum dot is smaller than that in the pyramid quantum dot. Numerical studies reveal that the Diamagnetic Susceptibility depends strongly on the geometry of the dot.
-
hydrogenic impurity states in a quantum pseudodot spin orbit interaction relativistic correction and Diamagnetic Susceptibility
International Journal of Theoretical Physics, 2013Co-Authors: R KhordadAbstract:We have studied three characteristics of a hydrogenic impurity located in the center of a quantum pseudodot within the effective mass approximation. These characteristics are the Diamagnetic Susceptibility, the spin-orbit interaction (SOI), and the relativistic correction (RC). First, we have solved analytically the Shrodinger equation without impurity by using the Laplace transformation. Then, we have applied the variational procedure to obtain energy levels and wave functions with a hydrogenic impurity in the center of quantum pseudodot. According to the results obtained from the present work reveals that (i) the Diamagnetic Susceptibility increases with increasing the pseudodot size, (ii) The mean value of r 2 increases when the pseudodot size increases, (iii) the SOI and RC increase by increasing the potential V 0, (iv) the RC and SOI approach to zero when the pseudodot increases, (v) the splitting between j=1/2 and 3/2 due to the SOI decreases by increasing pseudodot size.
-
hydrogenic impurity states in a spherical quantum antidot spin orbit interaction relativistic correction and Diamagnetic Susceptibility
European Physical Journal B, 2012Co-Authors: R Khordad, N Fathizadeh, S Davatolhagh, Alireza JafariAbstract:In the present work, we study three characteristics of a hydrogenic impurity located at the center of a GaAs/Ga1−x Al x As spherical quantum antidot within the effective mass approximation. These characteristics are the Diamagnetic Susceptibility, the spin-orbit interaction (SOI), and the relativistic correction (RC). First we outline the analytic solution of the corresponding Shrodinger equation with a hydrogenic impurity at the center and obtain the energy levels and wave functions. The results obtained from the present work reveal that the Diamagnetic Susceptibility increases with increasing the antidot size for finite barrier. The mean value of r 2 increases when the antidot size increases. The SOI and RC increase by increasing the concentration. The RC and SOI approach to zero when the antidot size increases. The splitting between j = 1/2 and 3/2 due to the SOI decreases by increasing antidot size.
-
simultaneous effects of temperature and pressure on Diamagnetic Susceptibility of a shallow donor in a quantum antidot
Physica B-condensed Matter, 2012Co-Authors: R Khordad, N FathizadehAbstract:Abstract The effect of temperature and pressure, simultaneously, on the Diamagnetic Susceptibility and binding energy of a hydrogenic donor impurity at the center of a GaAs / Ga 1 − x Al x As quantum antidot is studied within the effective mass approximation. For this goal, we first analytically solve the Schrodinger equation to obtain wavefunctions and energy levels. Then, using the electronic states, we can calculate the Diamagnetic Susceptibility. The results obtained from the present work reveals that (i) the Diamagnetic Susceptibility increases with increasing pressure, (ii) the Diamagnetic Susceptibility decreases by increasing temperature, (iii) the value of 〈 r 2 〉 decreases with increasing pressure due to the quantum confinement, and (iv) an increase in the pressure enhances the binding energy for a constant temperature.
H A Sarkisyan - One of the best experts on this subject based on the ideXlab platform.
-
effect of hydrostatic pressure on Diamagnetic Susceptibility of hydrogenic donor impurity in core shell shell spherical quantum dot with kratzer confining potential
Physica E-low-dimensional Systems & Nanostructures, 2016Co-Authors: D B Hayrapetyan, S M Amirkhanyan, E M Kazaryan, H A SarkisyanAbstract:Abstact The effect of the hydrostatic pressure on Diamagnetic Susceptibility of on-center hydrogenic donor impurity in G a 1 − x 1 A l x 1 A s / G a A s / G a 1 − x 2 A l x 2 A s core/shell/shell structure with Kratzer confining potential has been theoretically investigated in the framework of the effective mass approximation. The Diamagnetic Susceptibility has been calculated as a function of the characteristic parameters of Kratzer confining potential. With the increase of the hydrostatic pressure, the Diamagnetic Susceptibility increases. The same dependence from the depth of the Kratzer potential was obtained. However, the value of the Diamagnetic Susceptibility became saturated. The results show that with the potential minimum point increase, the Diamagnetic Susceptibility increases until some critical value, after which it decreases.
-
Effect of hydrostatic pressure on Diamagnetic Susceptibility of hydrogenic donor impurity in core/shell/shell spherical quantum dot with Kratzer confining potential
Physica E-low-dimensional Systems & Nanostructures, 2016Co-Authors: D B Hayrapetyan, S M Amirkhanyan, E M Kazaryan, H A SarkisyanAbstract:Abstact The effect of the hydrostatic pressure on Diamagnetic Susceptibility of on-center hydrogenic donor impurity in G a 1 − x 1 A l x 1 A s / G a A s / G a 1 − x 2 A l x 2 A s core/shell/shell structure with Kratzer confining potential has been theoretically investigated in the framework of the effective mass approximation. The Diamagnetic Susceptibility has been calculated as a function of the characteristic parameters of Kratzer confining potential. With the increase of the hydrostatic pressure, the Diamagnetic Susceptibility increases. The same dependence from the depth of the Kratzer potential was obtained. However, the value of the Diamagnetic Susceptibility became saturated. The results show that with the potential minimum point increase, the Diamagnetic Susceptibility increases until some critical value, after which it decreases.
B Vaseghi - One of the best experts on this subject based on the ideXlab platform.
-
simultaneous effects of pressure and temperature on the binding energy and Diamagnetic Susceptibility of a laser dressed donor in a spherical quantum dot
Physica B-condensed Matter, 2012Co-Authors: B Vaseghi, T SajadiAbstract:Abstract Binding energies and Diamagnetic Susceptibility of an impurity in a spherical GaAs quantum dot under the simultaneous influence of static pressure, temperature and laser radiation are investigated. Pressure- and temperature-dependent dressed potential which is produced by the combined effects of laser radiation and impurity considerably change the energy spectrum and Diamagnetic Susceptibility of the system. It is shown that binding energies and Diamagnetic Susceptibility increase with increasing pressure. Moreover, laser radiation effects on the Diamagnetic Susceptibility are not significant in comparison with its effects on the binding energy.
-
simultaneous effects of hydrostatic pressure and conduction band non parabolicity on binding energies and Diamagnetic Susceptibility of a hydrogenic impurity in spherical quantum dots
Communications in Theoretical Physics, 2011Co-Authors: G Rezaei, N A Doostimotlagh, B VaseghiAbstract:Simultaneous effects of conduction band non-parabolicity and hydrostatic pressure on the binding energies of 1S, 2S, and 2P states along with Diamagnetic Susceptibility of an on-center hydrogenic impurity confined in typical GaAs/AlxGa1 xAs spherical quantum dots are theoretically investigated using the matrix diagonalization method. In this regard, the effect of band non-parabolicity has been performed using the Luttinger-Kohn effective mass equation. The binding energies and the Diamagnetic Susceptibility of the hydrogenic impurity are computed as a function of the dot radius and different values of the pressure in the presence of conduction band non-parabolicity effect. The results we arrived at are as follows: the incorporation of the band edge non-parabolicity increases the binding energies and decreases the absolute value of the Diamagnetic Susceptibility for a given pressure and radius; the binding energies increase and the magnitude of the Diamagnetic Susceptibility reduces with increasing pressure.
-
conduction band non parabolicity effect on the binding energy and the Diamagnetic Susceptibility of an on center hydrogenic impurity in spherical quantum dots
Physica E-low-dimensional Systems & Nanostructures, 2011Co-Authors: G Rezaei, N A Doostimotlagh, B VaseghiAbstract:Energy eigenvalues, binding energy and Diamagnetic Susceptibility of an on-center hydrogenic impurity confined in typical GaAs/AlxGa1� xAs spherical quantum dots are theoretically investigated, using the matrix diagonalization method. In this regard, the effect of band non-parabolicity has been performed, by means of the Luttinger–Kohn effective mass equation. The lower-lying states, the binding energy and the Diamagnetic Susceptibility of the hydrogenic impurity are computed as a function of the dot size, with and without conduction band non-parabolicity effect. Results show that the band edge nonparabolicity considerably changes the electronic structure, the binding energy and the Diamagnetic Susceptibility, especially at small radii.
S Davatolhagh - One of the best experts on this subject based on the ideXlab platform.
-
hydrogenic impurity states in a spherical quantum antidot spin orbit interaction relativistic correction and Diamagnetic Susceptibility
European Physical Journal B, 2012Co-Authors: R Khordad, N Fathizadeh, S Davatolhagh, Alireza JafariAbstract:In the present work, we study three characteristics of a hydrogenic impurity located at the center of a GaAs/Ga1−x Al x As spherical quantum antidot within the effective mass approximation. These characteristics are the Diamagnetic Susceptibility, the spin-orbit interaction (SOI), and the relativistic correction (RC). First we outline the analytic solution of the corresponding Shrodinger equation with a hydrogenic impurity at the center and obtain the energy levels and wave functions. The results obtained from the present work reveal that the Diamagnetic Susceptibility increases with increasing the antidot size for finite barrier. The mean value of r 2 increases when the antidot size increases. The SOI and RC increase by increasing the concentration. The RC and SOI approach to zero when the antidot size increases. The splitting between j = 1/2 and 3/2 due to the SOI decreases by increasing antidot size.
-
binding energy and Diamagnetic Susceptibility of an on center hydrogenic donor impurity in a spherical quantum dot placed at the center of a cylindrical nano wire
Superlattices and Microstructures, 2012Co-Authors: Gh Safarpour, Mitra Barati, Mahmood Moradi, S Davatolhagh, A ZamaniAbstract:Abstract The binding energy and Diamagnetic Susceptibility of an on-center hydrogenic donor impurity in an InAs spherical quantum dot placed at the center of a GaAs cylindrical nano-wire have been investigated using finite element method in the framework of the effective mass approximation. The binding energy and Diamagnetic Susceptibility are calculated as a function of the dot radius, nano-wire radius and nano-wire height. The results show that as the dot radius increases (I) for a dot radius smaller than some critical value, the effect of the spherical confinement on the energy levels becomes negligible and the energies remain constant, for a dot radius larger than some specific value, the energy levels decrease (II) the ground and the first excited state binding energies increase, reach a maximum and then decrease (III) the ground state Diamagnetic Susceptibility increases, reach a maximum and then decreases (IV) the first excited state Diamagnetic Susceptibility increases, indicating two maxima and then decreases. The effects of the nano-wire dimensions on the binding energy and Diamagnetic Susceptibility have also been studied. We found that the binding energy and Diamagnetic Susceptibility decrease reach a minimum value and then increase as the nano-wire radius increases. Finally we found that as the height of the nano-wire increases the ground state binding energy decreases, reaches a minimum value and then increases but the first excited state binding energy decreases and reaches a constant value.