Excitons in a cylindrical GaAs Pöschl–Teller quantum dot

Barseghyan, M.G.; Duque, C.A.

doi:10.1002/pssb.201046428

Cited by 13 publications

(4 citation statements)

References 29 publications

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“…(i) a hydrogenic-like function with one variational parameter 69 70 and (ii) a trial function constructed from the product of two independent Gaussian functions. In this second case, two variational parameters were used to describe the radial problem and the problem along the axial direction separately 71 , 72 . Given the high computational consumption of this procedure, the test was performed for thos evalues of the electric and magnetic field for which the perturbative calculations showed a maximum in the binding energy.…”

Section: Resultsmentioning

confidence: 99%

“…10 d correspond to the expected value of the electron-hole Coulomb potential using the trial wave functions that are obtained once the energy associated with the full Hamiltonian in Eq. ( 1 ) is minimized with respect to the two variational parameters on which the trial wave functions depend 71 , 72 . A self-consistent calculation of excitonic states in structures with axial symmetry, such as that studied in this article, is in development and will be published elsewhere soon.…”

Section: Resultsmentioning

confidence: 99%

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Electronic structure of vertically coupled quantum dot-ring heterostructures under applied electromagnetic probes. A finite-element approach

Vinasco

Laroze

Radu

et al. 2021

Sci Rep

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We theoretically investigate the electron and hole states in a semiconductor quantum dot-quantum ring coupled structure, inspired by the recent experimental report by Elborg and collaborators (2017). The finite element method constitutes the numerical technique used to solve the three-dimensional effective mass equation within the parabolic band approximation, including the effects of externally applied electric and magnetic fields. Initially, the features of conduction electron states in the proposed system appear discussed in detail, under different geometrical configurations and values of the intensity of the aforementioned electromagnetic probes. In the second part, the properties of an electron-hole pair confined within the very kind of structure reported in the reference above are investigated via a model that tries to reproduce as close as possible the developed profile. In accordance, we report on the energies of confined electron and hole, affected by the influence of an external electric field, revealing the possibility of field-induced separate spatial localization, which may result in an indirect exciton configuration. In relation with this fact, we present a preliminary analysis of such phenomenon via the calculation of the Coulomb integral.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Electronic structure of vertically coupled quantum dot-ring heterostructures under applied electromagnetic probes. A finite-element approach

Vinasco

Laroze

Radu

et al. 2021

Sci Rep

Self Cite

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“…In Reference [46], and in this work, the electron-hole Coulomb interaction obtained via a perturbative calculation was corroborated with variational calculations, considering two types of trial functions: (i) a hydrogenic-like function with one variational parameter [48,49]; and (ii) a trial function constructed by the product of two independent Gaussian functions. In this second case, two variational parameters were used to describe the radial problem and the problem along the axial direction [50,51] separately. The results obtained by the perturbative calculation coincided with the variational ones in the margin of 97% for the binding energy.…”

Section: Theoretical Modelmentioning

confidence: 99%

Shallow Donor Impurity States with Excitonic Contribution in GaAs/AlGaAs and CdTe/CdSe Truncated Conical Quantum Dots under Applied Magnetic Field

et al. 2021

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Using the effective mass approximation in a parabolic two-band model, we studied the effects of the geometrical parameters, on the electron and hole states, in two truncated conical quantum dots: (i) GaAs-(Ga,Al)As in the presence of a shallow donor impurity and under an applied magnetic field and (ii) CdSe–CdTe core–shell type-II quantum dot. For the first system, the impurity position and the applied magnetic field direction were chosen to preserve the system’s azimuthal symmetry. The finite element method obtains the solution of the Schrödinger equations for electron or hole with or without impurity with an adaptive discretization of a triangular mesh. The interaction of the electron and hole states is calculated in a first-order perturbative approximation. This study shows that the magnetic field and donor impurities are relevant factors in the optoelectronic properties of conical quantum dots. Additionally, for the CdSe–CdTe quantum dot, where, again, the axial symmetry is preserved, a switch between direct and indirect exciton is possible to be controlled through geometry.

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“…Given this result, it can be deduced that the efficiency of quantum heat engines, which use quantum systems with unequally spaced energy levels, potentially can be higher than their equivalent classical heat engines, because altering the parameters of these systems can create an inhomogeneous shift of energy levels. As an example, PT potential which is used as confining potential of diatomic molecules 13,14 and quantum dots [15][16][17][18] , unlike the harmonic oscillator have unequally spaced energy levels. Therefore, using this potential as a working substance, can improve the efficiency of quantum heat engines.…”

Section: Introductionmentioning

confidence: 99%

Quantum Otto heat engine with Pöschl-Tellerpotential in contact with coherent thermal bath

Abasabadi

Mirafzali

Baghshahi

2023

Preprint

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Work and efficiency of quantum Otto heat engines (QOHEs) can increase by using non-thermal baths or by inhomogeneousscaling of energy levels of the working substance. Given these points, at first, we construct the coherent thermal state for atrigonometric Pöschl-Teller (PT) potential. Then using a particle in this potential, which has unequally spaced energy levels,as a working substance, we investigate the work extraction and the efficiency of QOHEs that operates between cold and hotcoherent thermal baths. The results show that changing the PT potential parameters in the adiabatic processes of QOHE,which causes an inhomogeneous shift in energy levels or/and make use of the hot coherent thermal bath, improve workextraction and efficiency of QOHE relative to the classical counterpart.

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Excitons in a cylindrical GaAs Pöschl–Teller quantum dot

Cited by 13 publications

References 29 publications

Electronic structure of vertically coupled quantum dot-ring heterostructures under applied electromagnetic probes. A finite-element approach

Electronic structure of vertically coupled quantum dot-ring heterostructures under applied electromagnetic probes. A finite-element approach

Shallow Donor Impurity States with Excitonic Contribution in GaAs/AlGaAs and CdTe/CdSe Truncated Conical Quantum Dots under Applied Magnetic Field

Quantum Otto heat engine with Pöschl-Tellerpotential in contact with coherent thermal bath

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