Yazar "Erdogan, I." seçeneğine göre listele

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    Binding energy and self-polarization as function of energy density in GaAs/AlAs quantum well wires
    (Elsevier Science Bv, 2006) Erdogan, I.; Akankan, O.; Akbas, H.
    In this work, we have investigated the effect of both external electric and magnetic fields on the ground-state binding energy and the self-polarization of hydrogenic impurity in square and cylindrical GaAs/AlAs quantum well wires as function of energy density and impurity position. The binding energies and self-polarizations were obtained using the effective-mass approximation within a variational scheme. (c) 2006 Elsevier B.V. All rights reserved.
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    Binding energy of 2p-bound state of a hydrogenic donor impurity in a GaAs/Ga1-xAlxAs spherical quantum dot under hydrostatic pressure
    (Elsevier, 2014) Bulut, P.; Erdogan, I.; Akbas, H.
    By using a variational procedure within the effective mass approximation, we calculated the 2p state binding energy, E-2pha(x,P), and the binding energy turning point, R-2pEbT (X, P) of a hydrogenic donor impurity located at the centre of the GaAs GaAs/Ga1-xAlxAs spherical quantum dot under the influence of hydrostatic pressure. The results obtained show that the binding energy turning point, R-2pEbT(X, P) is an important factor in dealing with the 2p bound state of a hydrogenic donor impurity embedded at the centre of the quantum dot. (C) 2014 Elsevier By. All rights reserved,
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    The effect of dielectric constant on binding energy and impurity self-polarization in a GaAs-Ga1-xAlxAs spherical quantum dot
    (Indian Assoc Cultivation Science, 2017) Mese, A. I.; Cicek, E.; Erdogan, I.; Akankan, O.; Akbas, H.
    The ground state, 1s, and the excited state, 2p, energies of a hydrogenic impurity in a GaAs-Ga1-xAlxAs spherical quantum dot, are computed as a function of the donor positions. We study how the impurity self-polarization depends on the location of the impurity and the dielectric constant. The excited state anomalous impurity self-polarization in the quantum dot is found to be present in the absence of any external influence and strongly depends on the impurity position and the radius of the dot. Therefore, the excited state anomalous impurity self-polarization can give information about the impurity position in the system. Also, the variation of E-b1s and E-b2p with the dielectric constant can be utilized as a tool for finding out the correct dielectric constant of the dot material by measuring the 1s or 2p state binding energy for a fixed dot radius and a fixed impurity position.
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    The effects of geometrical shape and impurity position on the self-polarization of a donor impurity in an infinite GaAs/AlAs tetragonal quantum dot
    (Indian Assoc Cultivation Science, 2021) Akankan, O.; Erdogan, I.; Mese, A. I.; Cicek, E.; Akbas, H.
    Using the variational method within the effective-mass approximation, the effects of geometrical shape and impurity position on the ground-state self-polarization and binding energy of a donor impurity are theoretically studied for the infinite GaAs/AlAs tetragonal quantum dot. We have found that the ground-state self-polarization and binding energy depend on geometrical shape and impurity-AlAs layer distance.
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    Effects of hydrostatic pressure on the self-polarization in GaAs/Ga1-x Alx As quantum wells under the electric field
    (Elsevier Science Bv, 2009) Erdogan, I.; Akankan, O.; Akbas, H.
    In this work we have calculated the hydrostatic pressure and the electric field effect on the self-polarization (SP) in GaAs/Ga1-xAlx As quantum well, The binding energies of donors and the self-polarization in quantum wells are investigated with a variational method considering the influence of finite barriers under hydrostatic pressure. In calculations, we take into account the electronic effective mass, dielectric constant, barrier height, well size, varying with pressure. We find that the effect of hydrostatic pressure on the self-polarization depends on value of the well widths and applied electric fields. (C) 2009 Elsevier B.V. All rights reserved.
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    Ground state normalized binding energy of impurity in asymmetric quantum wells under hydrostatic pressure
    (Academic Press Ltd- Elsevier Science Ltd, 2016) Akbas, H.; Sucu, S.; Minez, S.; Dane, C.; Akankan, O.; Erdogan, I.
    We have studied and computed variationally the impurity energy, impurity energy turning points, and ground state normalized binding energy as functions of the impurity position for shallow impurity in asymmetric quantum wells under hydrostatic pressure. We found that the normalized binding energy significantly depends on the asymmetry of the well, besides depending on,the impurity position and hydrostatic pressure. Also, the dependence of the positive normalized binding energy on the pressure can be used to find out the degree of the asymmetry of the well or the impurity position in the well. (C) 2016 Elsevier Ltd. All rights reserved.
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    Hydrogenic donor in asymmetric AlxLGa1-xLAs/GaAs/AlxRGa1-xRAs quantum wells
    (Elsevier Science Bv, 2014) Akbas, H.; Dane, C.; Erdogan, I.; Akankan, O.
    In this work we study the effects of barrier height ratio V-L/V-R on asymmetric AlxLGa1-xLAs/GaAs/AlxRGa1-xRAs quantum wells in absence of external influences. We use a variational method within the effective mass approximation to observe the effects of the barrier height ratio. It has been observed that the binding energy of the impurity, the expectation value of the electron-impurity distance along the z-direction, density of impurity states, and edge binding energy difference depend strongly on the barrier height ratio. Furthermore we present new curves that analyze the binding energy of asymmetric quantum wells as functions of barrier height ratio. (C) 2014 Elsevier B.V. All rights reserved.
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    Hydrostatic pressure effects on impurity states in GaAs/AlAs quantum wells
    (Academic Press Ltd- Elsevier Science Ltd, 2011) Akbas, H.; Erdogan, I.; Akankan, O.
    Within the framework of effective-mass approximation, we have studied the effects of hydrostatic pressure on the binding energy of a shallow donor impurity in an infinite quantum well by means of a variational method. It is found that the first derivative of the binding energy and energy shift is reliable parameter for describing the structure. (C) 2011 Elsevier Ltd. All rights reserved.
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    Laser field effect on the normalized self-polarization, self-polarization and binding energy in square quantum wells made of different materials
    (Elsevier, 2023) Mese, A. I.; Cicek, E.; Ozkapi, S. G.; Ozkapi, B.; Erdogan, I.
    In this study, we examine the effect of the laser field on normalized self-polarization, self-polarization, and binding energy in square quantum wells made of four different materials under effective mass approximation. The effects of well width, laser field, and impurity position on normalized self-polarization, self-polarization, and binding energies are shown in detail. The subband energies are obtained by the finite difference method, and the impurity energies are calculated by the variational method. The laser field significantly affects binding energy, self-polarization, and normalized self-polarization. The term normalized self-polarization is defined for the first time in this study. This allows a more detailed examination of the self-polarization change depending on the impurity position. Examining the laser field effect, especially in square quantum wells made of different materials, will provide researchers with helpful information about the importance of material selection in calculating binding energy, self-polarization, and normalized self-polarization.
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    Simultaneous effects of temperature, hydrostatic pressure and electric field on the self-polarization and electric field polarization in a GaAs/Ga0.7Al0.3As spherical quantum dot with a donor impurity
    (Academic Press Ltd- Elsevier Science Ltd, 2013) Erdogan, I.; Akankan, O.; Akbas, H.
    Based on the effective mass approximation within a variational approach, we have calculated the temperature effect on the donor binding energy, self-polarization (SP), and electric field polarization (FP) in a GaAs/Ga0.7Al0.3As spherical quantum dot (SQD) with off center donor impurity under the action of electric field and hydrostatic pressure. The binding energy and polarizations are computed as a function of the temperature, and electric field strength for two different pressures. The results show that the values of the self-polarization are greater than the values of the electric field polarization. There are no reports on comparison of the SP and FP in low-dimensional structures, so far. (C) 2013 Published by Elsevier Ltd.
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    Spatial electric field effect on the self-polarization in GaAs/AlAs square quantum-well wires
    (Elsevier Science Bv, 2006) Akankan, O.; Erdogan, I.; Akbas, H.
    In the presence of a spatial electric field the ground-state energy and self-polarization (SPE) of hydrogenic impurity in infinite square quantum-well wire is calculated, where the spatial electric field is applied parallel to the position vector of the impurity. It is found that impurity ground-state energy and SPE depend strongly on the axial component of the spatial electric field and on the coordinates of the impurity position x(i),y(i), and z(i). (c) 2006 Elsevier B.V. All rights reserved.