Dynamics of excitons and Coulomb beats in a quantum dot molecule

Degani, Marcos H.; Farias, G. A.; Farinas, Paulo F.

doi:10.1063/1.2359574

Cited by 10 publications

(10 citation statements)

References 12 publications

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“…We note that the resonance of the exciton occurs at a higher field making evident the strong Coulomb interaction between the electron and hole within the exciton. 11,13 Comparision between Figs. 8͑a͒ and 8͑b͒ demonstrates the different dependence on the system thicknesses, but also make evident some similarities.…”

Section: Resultsmentioning

confidence: 79%

“…8͑a͒ and 8͑b͒ are also shown the exciton transitions energies X 0/1 0 calculated in a similar manner. 13 The comparision between the X 0 and the X ± energies allows us to see the stability of the trion state and its binding energy. We note that the resonance of the exciton occurs at a higher field making evident the strong Coulomb interaction between the electron and hole within the exciton.…”

Section: Resultsmentioning

confidence: 99%

“…Excitons in asymmetric double quantum dots have also been studied by several authors. [12][13][14] Specifically for the trions in double quantum dots, the electric-field dependent optical spectra have shown anticrossings of the spectral lines related to the level repulsion which are characteristic of a pair of quantum systems which are coupled. This coupling effect occurs in a controllable system of three interacting particles.…”

Section: Introductionmentioning

confidence: 99%

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Resonances of trion states in quantum dot molecules tuned by an electric field

Degani¹,

Maialle²

2007

Phys. Rev. B

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The quantum states of the trion ͑two electrons and one hole X − or two holes and one electron X + ͒ in double quantum dots are theoretically investigated within the effective-mass approximation for a quasi-onedimensional model: the numerical method employed is exact in the sense that it does not rely on basis-set expansions nor on perturbative or variational approaches. We have investigated the tuning by the electric field of the energy levels into resonance showing crossing and anticrossing patterns. The ground and the excited states, for the spin-singlet and spin-triplet configurations, are calculated and discussed. The electric-field dependent spectra for the X − and X + trions are similar, although they depend differently on the system parameters which define the confining potential. The oscillator strengths of the trion optical transitions are calculated for the first time for the double dot systems. For both types of trions, we found good agreement between calculations and the existing photoluminescence data obtained from vertically stacked double quantum dots. For a system of symmetric dots, we predict a parabolic dependence of the energy level of the triplet ground state on the electric field and substantially different patterns of the level anticrossings in the optical spectra.

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Section: Resultsmentioning

confidence: 79%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Resonances of trion states in quantum dot molecules tuned by an electric field

Degani¹,

Maialle²

2007

Phys. Rev. B

Self Cite

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“…Quantum dot molecules attract much attention because of the constant technological progress in manufacturing high quality vertically stacked quantum dots using spontaneous formation in a Stransky–Krastanov process. The Coulomb interaction between charged particles leads to the formation of excitons in a single quantum dot and quantum dot molecule . The external static electric field can be applied to control the optical properties of the quantum dot molecule.…”

Section: Introductionmentioning

confidence: 99%

Excitonic States and Photoluminescence Spectra of a Quantum Dot Molecule Exposed to the External Static Electric Field

Schillak

2018

Physica Status Solidi (b)

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The influence of a static electric field on the energy levels, wave functions, and optical properties of excitons in a quantum dot molecule is analyzed. Taking into account the cylindrical symmetry of the molecule, the wave functions and excitonic energies are calculated when the external constant electric field is applied along the symmetry axis. Two dots separated by a narrow barrier are considered as one system of three‐dimensional potential wells for an electron and a hole. The six‐dimensional Schrödinger equation is transformed into the equivalent eigenvalue problem given by the system of the coupled two‐dimensional second order differential equations as the separation of the relative‐ and center‐of‐mass motion of an electron and a hole is not possible in this case. The differential equations are solved numerically using finite differences method. Having the eigenfunctions and eigenvalues, the excitonic photoluminescence intensity is calculated and analyzed. As an example, the configuration indicating on the possibility of non‐monotonic behavior of the photoluminescence intensity versus electric field is discussed. The comparison of numerical results with experimental data for the GaInAs quantum dot molecule is presented. Satisfactory agreement with the available experimental data is obtained.

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“…Recent experiments [16][17][18][19][20][21][22] and theoretical papers [27][28][29][30] on the electric field effect concerned only artificial molecules formed by a pair of dots. Nevertheless, the growth technique can be applied for production of stacks of multiple dots [1,2].…”

Section: Stack Of Three Dots In Vertically-oriented Electric Fieldmentioning

confidence: 99%

Coupled Quantum Dots - Spatial Correlations between Interacting Carriers

Szafran

2008

Acta Phys. Pol. A

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We review results of our modeling of excitons and excitonic trions confined in vertically stacked InGaAs/GaAs self-assembled quantum dots. Electrons and holes in double quantum dots are much more significantly correlated than in a single dot. For that reason our modeling was based on simple confinement potentials that allow for an exact diagonalization of the resulting two-and three-particle Hamiltonians with a precise account for the relative electron and hole localization along the stack. We studied the optical signatures of the coupling in context of the photoluminescence experiments performed in the external electric field. The calculations predicted prior to the experiment the mechanism of the exciton and negative trion dissociation by electron removal from the dot occupied by the hole. We discuss the competition between the tunnel and the electrostatic interdot couplings. Effects of the non-perfect alignment of the dots as well as stacks containing more than two dots are also discussed.

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Dynamics of excitons and Coulomb beats in a quantum dot molecule

Cited by 10 publications

References 12 publications

Resonances of trion states in quantum dot molecules tuned by an electric field

Resonances of trion states in quantum dot molecules tuned by an electric field

Excitonic States and Photoluminescence Spectra of a Quantum Dot Molecule Exposed to the External Static Electric Field

Coupled Quantum Dots - Spatial Correlations between Interacting Carriers

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