Influence of electric field on direct and indirect exciton in a concentrically coupled quantum ring heterostructure embedded in SiO2 matrix

Sherly, I. Janet; Nithiananthi, P.

doi:10.1016/j.spmi.2019.106334

Cited by 7 publications

(4 citation statements)

References 27 publications

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“…The trial wavefunction of the exciton is given by The physical parameters are calculated in atomic units (where e = ħ = m 0 = 1) and they are later converted to SI units. Table 1 gives the material parameters used in the calculation [9][10][11].…”

Section: Theoretical Formalismmentioning

confidence: 99%

“…Spin and energy transfer from the photogenerated carriers to the metal ions provides route to the production of next generation structures and devices. Study on the effect of electric field on the energy levels of exciton [11] would be a more sensible approach to explore some of the interesting optical properties of this material. The effectiveness of optical studies lies in the ability to determine the transition energy of the system precisely [9].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Electrically induced direct to indirect exciton transition in CdTe/CdMnTe concentric double quantum ring rooted in SiO₂ matrix

Sherly,

Nithiananthi

2024

Phys. Scr.

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Effect of electric field and ring dimension on the localization of direct and indirect exciton formed inside a CdTe/CdMnTe Concentric Double Quantum Ring (CDQR) has been studied using variational technique. The whole double ring structure is embedded inside a SiO2 matrix to enhance exciton localization. Electric field applied along the axial (z) axis tilts the band structure which promotes the carrier localization more in the edges than in the center of the ring. Thus, the stronger electric field gives a triangular confinement to the carrier in the edges which enhances the carrier stability. Along with the effect of electric field the ring dimension which determines the stability of the exciton retains has been estimated through the mean square distance. The effect of the location of the constituent carriers on the excitonic stability and the efficient carrier transfer from inner ring to outer ring has been calculated for both symmetric and asymmetric ring dimensions. Height of the ring has been varied to understand its effect on the localization of both direct and indirect exciton.

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Section: Theoretical Formalismmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Electrically induced direct to indirect exciton transition in CdTe/CdMnTe concentric double quantum ring rooted in SiO₂ matrix

Sherly,

Nithiananthi

2024

Phys. Scr.

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“…Such is the case in [15,16], where the breaking degeneration is observed because of magnetic field influence. In [17], the effects on direct and indirect exciton are studied in vertically coupled QRs under the application of an electric field, generating a triangular shape potential. Another work, Ref.…”

Section: Introductionmentioning

confidence: 99%

Spin–Orbit and Zeeman Effects on the Electronic Properties of Single Quantum Rings: Applied Magnetic Field and Topological Defects

et al. 2023

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Within the framework of effective mass theory, we investigate the effects of spin–orbit interaction (SOI) and Zeeman splitting on the electronic properties of an electron confined in GaAs single quantum rings. Energies and envelope wavefunctions in the system are determined by solving the Schrödinger equation via the finite element method. First, we consider an inversely quadratic model potential to describe electron confining profiles in a single quantum ring. The study also analyzes the influence of applied electric and magnetic fields. Solutions for eigenstates are then used to evaluate the linear inter-state light absorption coefficient through the corresponding resonant transition energies and electric dipole matrix moment elements, assuming circular polarization for the incident radiation. Results show that both SOI effects and Zeeman splitting reduce the absorption intensity for the considered transitions compared to the case when these interactions are absent. In addition, the magnitude and position of the resonant peaks have non-monotonic behavior with external magnetic fields. Secondly, we investigate the electronic and optical properties of the electron confined in the quantum ring with a topological defect in the structure; the results show that the crossings in the energy curves as a function of the magnetic field are eliminated, and, therefore, an improvement in transition energies occurs. In addition, the dipole matrix moments present a non-oscillatory behavior compared to the case when a topological defect is not considered.

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“…Several very recent studies have dealt with various physical processes in double quantum rings (DQRs): the influence of the electric field (EF) on excitons [13], the effects of the magnetic field and ring dimension [14], magneto-optical absorption [15], and optical rectification [16]. In this work, we theoretically investigate a DQR model inspired by a real semiconductor structure manufactured by another collective [17] through the droplet epitaxy technique.…”

Section: Introductionmentioning

confidence: 99%

Finite element 3D model of a double quantum ring: effects of electric and laser fields on the interband transition

Radu,

Stan,

Bejan

2023

New J. Phys.

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In this work, the changes in the energy of electrons and holes, oscillator strength and interband transition time when external fields are applied to a GaAs/AlGaAs semiconductor double ring grown by the droplet epitaxy technique are theoretically analyzed. We consider a static electric field and an intense laser field nonresonant with the quantum structure, with variable intensities and orientations with respect to the symmetry axis of the quantum ring (QR). In the formalism of the effective mass approximation for electrons and holes, the energies and wavefunctions were numerically computed using the finite element method implemented with an accurate three-dimensional model of the real QR. Laser dressing of the confining potential was performed using the exact integration formula at each point. Our results show major differences between the effects of the two types of applied fields, caused mainly by the static electric-field-induced strong polarizability of the confined electron-hole pair. In addition, the effects of both fields exhibit strong anisotropy in the electronic properties as a result of the particular flattened geometry of the QR. Proper combinations of field strengths and orientations are helpful in designing accurate tools for the sensitive manipulation of interband radiative properties.

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Influence of electric field on direct and indirect exciton in a concentrically coupled quantum ring heterostructure embedded in SiO2 matrix

Cited by 7 publications

References 27 publications

Electrically induced direct to indirect exciton transition in CdTe/CdMnTe concentric double quantum ring rooted in SiO₂ matrix

Electrically induced direct to indirect exciton transition in CdTe/CdMnTe concentric double quantum ring rooted in SiO₂ matrix

Spin–Orbit and Zeeman Effects on the Electronic Properties of Single Quantum Rings: Applied Magnetic Field and Topological Defects

Finite element 3D model of a double quantum ring: effects of electric and laser fields on the interband transition

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Influence of electric field on direct and indirect exciton in a concentrically coupled quantum ring heterostructure embedded in SiO2 matrix

Cited by 7 publications

References 27 publications

Electrically induced direct to indirect exciton transition in CdTe/CdMnTe concentric double quantum ring rooted in SiO2 matrix

Electrically induced direct to indirect exciton transition in CdTe/CdMnTe concentric double quantum ring rooted in SiO2 matrix

Spin–Orbit and Zeeman Effects on the Electronic Properties of Single Quantum Rings: Applied Magnetic Field and Topological Defects

Finite element 3D model of a double quantum ring: effects of electric and laser fields on the interband transition

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Electrically induced direct to indirect exciton transition in CdTe/CdMnTe concentric double quantum ring rooted in SiO₂ matrix

Electrically induced direct to indirect exciton transition in CdTe/CdMnTe concentric double quantum ring rooted in SiO₂ matrix