Thermodynamic properties of two-dimensional few-electrons quantum dot using the static fluctuation approximation (SFA)

Nammas, F.S.; Sandouqa, A. S.; Ghassib, H. B.; Al-Sugheir, M. K.

doi:10.1016/j.physb.2011.09.058

Cited by 31 publications

(16 citation statements)

References 33 publications

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“…A parabolic potential was chosen because they have been used extensively 23,25,26,[100][101][102][103][104][105][106][107][108][109] to represent the confinement potential experienced by excitons in nanoparticles. The values of the force constant parameter, k, were selected such that the confining potential spanned from weakly confining region (k = 1.0 × 10 −4 a.u.)…”

Section: Physical System and Computational Detailsmentioning

confidence: 99%

Development of the Multicomponent Coupled-Cluster Theory for Investigation of Multiexcitonic Interactions

Ellis

Aggarwal²,

Chakraborty

2015

J. Chem. Theory Comput.

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Multicomponent systems are defined as chemical systems that require a quantum mechanical description of two or more different types of particles. Non-Born-Oppenheimer electron-nuclear interactions in molecules, electron-hole interactions in electronically excited nanoparticles, and electron-positron interactions are examples of physical systems that require a multicomponent quantum mechanical formalism. The central challenge in the theoretical treatment of multicomponent systems is capturing the many-body correlation effects that exist not only between particles of identical types (electron-electron) but also between particles of different types (electron-nuclear and electron-hole). In this work, the development and implementation of multicomponent coupled-cluster (mcCC) theory for treating particle-particle correlation in multicomponent systems are presented. This method provides a balanced treatment of many-particle correlation effects in a general multicomponent system while maintaining a size-consistent and size-extensive formalism. The coupled-cluster ansatz presented here is an extension of the electronic structure CCSD formulation for multicomponent systems and is defined as |ΨmcCC⟩ = eT1I+T2I+T1II+T2II+T11I,II+T12I,II+T21I,II+T22I,II|0I0II⟩. The cluster amplitudes in the mcCC wave function were obtained by projecting the mcCC Schrödinger equation onto a direct product space of singly and doubly excited states of type I and II particles and then solving the resulting mcCC equations iteratively. These equations were derived using an automated application of the generalized Wick’s theorem and were implemented using a computer-assisted source code generation approach. The applicability of the mcCC method was demonstrated by calculating ground state energies of multicomponent Hooke's atom and positronium hydride systems as well as by calculating exciton and biexciton binding energies in multiexcitonic systems. For each case, the mcCC results were benchmarked against full configuration interaction (FCI) calculations and were found to be in excellent agreement with the FCI results. The effect of neglecting certain classes of multicomponent connected excitation terms from the mcCC wave function was also investigated. The results from this study demonstrate that connected cluster operators that generate simultaneous excitation in type I and type II space are critical for capturing electron-hole correlation in multiexcitonic systems.

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Section: Physical System and Computational Detailsmentioning

confidence: 99%

Development of the Multicomponent Coupled-Cluster Theory for Investigation of Multiexcitonic Interactions

Ellis

Aggarwal²,

Chakraborty

2015

J. Chem. Theory Comput.

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“…The effective Hamiltonian in Eq. (8) was used in combination with parabolic potential which has been used extensively [99][100][101][102][103][104][105][106][107][108] for approximating the confining potential in quantum dots and wires. The electron and hole external potentials v α ext were expressed as…”

Section: Theorymentioning

confidence: 99%

Effect of Dot Size on Exciton Binding Energy and Electron–Hole Recombination Probability in CdSe Quantum Dots

Elward

Chakraborty

2013

J. Chem. Theory Comput.

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Large exciton binding energy Small exciton binding energy Cd 74608 Se 74837 Cd 199 Se 195 Cd 1012 Se 1063 ΔE ΔE ΔE valence valence conduction conduction conduction valence 0 0.5 1 EBE 0 0.5 1 EBE 0 0.5 1 EBE Peh Peh Peh Radius of quantum dotExciton binding energy and electron-hole recombination probability are presented as the two important metrics for investigating effect of dot size on electronhole interaction in CdSe quantum dots. Direct computation of electron-hole recombination probability is challenging because it requires an accurate mathematical description of electron-hole wavefunction in the neighborhood of the electron-hole coalescence point. In this work, we address this challenge by solving the electron-hole Schrodinger equation using the electron-hole explicitly correlated Hartree-Fock (eh-XCHF) method. The calculations were performed for a series of CdSe clusters ranging from Cd 20 Se 19 to Cd 74608 Se 74837 that correspond to dot diameter range of 1 − 20 nm. The calculated exciton binding energies and electron-hole recombination probabilities were found to decrease with increasing dot size. Both of these quantities were found to scale as D −n dot with respect to the dot diameter D. One of the key insights from this study is that the electron-hole recombination probability decreases at a much faster rate than the exciton binding energy as a function of dot size. It was found that an increase in the dot size by a factor of 16.1, resulted in a decrease in the exciton binding energy and electron-hole recombination probability by a factor of 14.4 and 5.5 × 10 6 , respectively.

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“…[20], the authors used the static fluctuation approximation (SFA) to study the thermodynamic properties of two-dimensional GaAs/AlGaAs parabolic QD in a magnetic field. Boyacioglu and Chatterjee [21] studied the magnetic properties of a single quantum dot confined with a Gaussian potential model.…”

Section: Introductionmentioning

confidence: 99%

Magnetic Susceptibility of Coupled Double GaAs Quantum Dot in Magnetic Fields

Elsaid

Hijaz

2017

Acta Phys. Pol. A

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We calculate the magnetic susceptibility of two interacting electrons confined in a coupled double quantum dot presented in a magnetic field by solving the relative Hamiltonian using the combined variational and exact diagonalization methods. We have investigated the dependence of the magnetic susceptibility on temperature, magnetic field strength, confining frequency, and barrier height. The singlet-triplet transitions in the ground state of the quantum dot spectra and the corresponding jumps in the magnetic susceptibility curves have been shown. The comparisons show that our results are in very good agreement with reported works.

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Thermodynamic properties of two-dimensional few-electrons quantum dot using the static fluctuation approximation (SFA)

Cited by 31 publications

References 33 publications

Development of the Multicomponent Coupled-Cluster Theory for Investigation of Multiexcitonic Interactions

Development of the Multicomponent Coupled-Cluster Theory for Investigation of Multiexcitonic Interactions

Effect of Dot Size on Exciton Binding Energy and Electron–Hole Recombination Probability in CdSe Quantum Dots

Magnetic Susceptibility of Coupled Double GaAs Quantum Dot in Magnetic Fields

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