Excitonic fine structure and binding energies of excitonic complexes in single InAs quantum dashes

Mrowiński, P.; Zieliński, Michał; Świderski, M.; Misiewicz, J.; Somers, A.; Reithmaier, J.P.; Höfling, Sven; Sęk, G.

doi:10.1103/physrevb.94.115434

Cited by 22 publications

(29 citation statements)

References 69 publications

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“…These dimensions are typical for self-assembled quantum dots and quantum dashes. 21 In our previous work 54 we have studied effects of nanostructure size and composition on quantum dashes spectra, here focus on the role of lateral deformation for pure InAs/InP system. The anisotropy is applied as by elongating the system along [110] axis and shrinking it in the perpendicular [110] axis at the same time, such that the base field (and the overall dot volume) is kept constant.…”

Section: A System and Methodsmentioning

confidence: 99%

From quantum dots to quantum dashes: Excitonic spectra of highly elongated InAs/InP nanostructures

Zieliński

2019

Phys. Rev. B

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A transition from a cylindrical quantum dot to a highly elongated quantum dash is theoretically studied here with an atomistic approach combining empirical tight binding for single particle states and configuration interaction method for excitonic properties. Large nanostructure shape anisotropy leads to a peculiar trend of the bright exciton splitting, which at certain point is quenched with further shape elongation, contradicting predictions of simplified models. Moreover strong shape elongation promotes pronounced optical activity of the dark exciton, that can reach substantial 1% fraction of the bright exciton intensity without application of any external fields. An atomistic calculation is augmented with a elementary phenomenological model expressed in terms of lighthole exciton add-mixture increasing with the shape deformation. Finally, exctionic complexes X − , X + , and XX are studied as well and the correlations due to presence of higher excited states are identified as a key-factor affecting excitonic binding energies and the fine structure.

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Section: A System and Methodsmentioning

confidence: 99%

From quantum dots to quantum dashes: Excitonic spectra of highly elongated InAs/InP nanostructures

Zieliński

2019

Phys. Rev. B

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“…1(a), we present normalized (to maximum intensities) µPL spectra from a single QDash within the 500 × 250 nm 2 mesa recorded at 5 K and 75 K. The spectral line marked with an arrow is the one identified as originating from the negatively charged exciton (X − ), based on the characteristic linear excitation-power dependence of intensity and no fine-structure splitting as shown in previous studies. 26,29,30 A common redshift of the luminescence peaks with temperature is present due to the thermal shrinkage of the material band-gap. At T = 5 K the considered peak has a Gaussian profile with the linewidth of ∼0.2 meV, which indicates an inhomogeneous impact of the environment.…”

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Strongly temperature-dependent recombination kinetics of a negatively charged exciton in asymmetric quantum dots at 1.55 µm

Dusanowski

Gawełczyk

Misiewicz

et al. 2018

Applied Physics Letters

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We report on strongly temperature-dependent kinetics of negatively charged carrier complexes in asymmetric InAs/AlGaInAs/InP quantum dots (dashes) emitting at telecom wavelengths. The structures are highly elongated and of large volume, which results in atypical carrier confinement characteristics with s-p shell energy splittings far below the optical phonon energy, which strongly affects the phonon-assisted relaxation. Probing the emission kinetics with time-resolved microphotoluminescence from a single dot, we observe a strongly non-monotonic temperature dependence of the charged exciton lifetime. Using a kinetic rate-equation model, we find that a relaxation side-path through the excited charged exciton triplet states may lead to such behavior. This, however, involves efficient singlettriplet relaxation via the electron spin-flip. Thus, we interpret the results as an indirect observation of strongly enhanced electron spin relaxation without magnetic field, possibly resulting from atypical confinement characteristics.Due to the three-dimensional quantum confinement, various carrier complexes can be created within semiconductor nanostructures, including charged excitons (trions) that are composed of the electron-hole pair and an additional electron or hole. Trions have been extensively studied in quantum dots (QDs) from the point of view of resident spin initialization, 1,2 single photon generation 3 (no dark states limiting emission rates, contrary to neutral excitons) as well as in implementations of light-matter interfaces for spin-photon 4-6 and spinspin entanglement generation. 7-11 For these applications, understanding the occupation kinetics of carrier states and the resulting light emission is of particular importance. While it has been studied at low temperatures, 12-15 systematic studies concerning the temperature dependence of trion emission dynamics in epitaxial nanostructures are needed.Quantum dashes (QDashes) are nanostructures that are strongly elongated in one of the in-plane directions, with discrete carrier energy levels inherited from similar but much more symmetric QDs. 16,17 Typically, their width is in the range of 10-30 nm, whereas the length may vary up to above 100 nm. In InAs on InP structures, this shape asymmetry may emerge spontaneously during the epitaxial growth in a self-assembled manner. 18,19 The optical properties of such QDashes have been the subject of many studies focused on both ensembles 20-23 and single objects. [24][25][26][27][28][29][30] This has been motivated by their compatibility with modern semiconductor-based optoelectronics and nanophotonics, as well as the emission at telecom wavelengths. This makes such structures promising for future technologies involving fiber-based quantum communication and information processing. Recently, single-photon emission from india) Electronic mail: michal.gawelczyk@pwr.edu.pl vidual QDashes at telecom wavelengths up to T =80 K has been demonstrated, 30 showing their suitability for implementation in quantum-information technolog...

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“…In addition, we cannot neglect the influence of the excess carriers on entire kinetics which has evidently been the case for the excitation power dependence in the cwexcitation as shown elsewhere [18].…”

Section: P Mrowiński Et Almentioning

confidence: 99%

“…Based on that, the bright-dark states splitting is equal to 440 µeV, the binding energies of biexciton and trion are -3.1 meV and -5.6 meV, respectively. Strongly bound state of the charged exciton suggests this is the negatively charged trion [16][17][18], which could be expected for nanostructures deposited on InP substrate being unintentionally n-doped with substantial concentration of the excess electrons. Typically, as for small quantum dots, one would expect that the XX D PL line has significantly lower intensity than X D one due to the spin relaxation from bright to dark exciton which populates the X D states.…”

Section: Introductionmentioning

confidence: 99%

InAs on InP Quantum Dashes as Single Photon Emitters at the Second Telecommunication Window: Optical, Kinetic, and Excitonic Properties

Mrowiński

Dusanowski

Somers³

et al. 2017

Acta Phys. Pol. A

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In this work, InAs/InGaAlAs/InP quantum dashes have been investigated in terms of their optical, kinetic, and excitonic properties with respect to their application within the 1300 ± 40 nm spectral range, i.e. the Oband of the telecommunication technologies. We focused on the basic excitonic complexes such as neutral exciton, biexciton, and charged exciton, which have been identified by means of photoluminescence measurements. Emission and carriers' dynamics have been analyzed using rate equation model and fitting the experimental data obtained for both continuous-wave and pulsed excitation regimes. There has been found a significant impact of the charge carrier imbalance in the system and electron capturing rate on the dynamics of the optical and electronic transitions, which results in high occupation of the negatively charged trion state. Autocorrelation measurements show clear antibunching of trion emission for non-resonant excitation which indicates a potential of such kind of emitters as single photon sources for short-range quantum communication schemes.

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Excitonic fine structure and binding energies of excitonic complexes in single InAs quantum dashes

Cited by 22 publications

References 69 publications

From quantum dots to quantum dashes: Excitonic spectra of highly elongated InAs/InP nanostructures

From quantum dots to quantum dashes: Excitonic spectra of highly elongated InAs/InP nanostructures

Strongly temperature-dependent recombination kinetics of a negatively charged exciton in asymmetric quantum dots at 1.55 µm

InAs on InP Quantum Dashes as Single Photon Emitters at the Second Telecommunication Window: Optical, Kinetic, and Excitonic Properties

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