Band-gap renormalization in quantum wires

Cingolani, R.; Rinaldi, R.; Ferrara, M.; Rocca, G. C. La; Lage, H.; Heitmann, D.; Ploog, K.; Kalt, H.

doi:10.1103/physrevb.48.14331

Cited by 52 publications

(56 citation statements)

References 19 publications

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“…To the best of our knowledge, this is the first calculation of electronic many-body BGR correction in QW systems including full effects of both the dynamical electron-electron and Fröhlich electron-LO-phonon interactions treated on an equal footing. We find that the calculated BGR using the full RPA dielectric function agrees very well with available experimental results [4] and depends on both the electron-hole density and quantum wire widths. Our calculated BGR in quantum wires shows an approximate materials independent two-parameter universality as a function of the scaled plasma density and wire width.…”

supporting

confidence: 81%

Band-gap renormalization in photoexcited semiconductor quantum-wire structures in theGWapproximation

Hwang

Sarma

1998

Phys. Rev. B

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We investigate the dynamical self-energy corrections of the electron-hole plasma due to electron-electron and electron-phonon interactions at the band edges of a quasi-one dimensional (1D) photoexcited electron-hole plasma. The leading-order GW dynamical screening approximation is used in the calculation by treating electron-electron Coulomb interaction and electron-optical phonon Fröhlich interaction on an equal footing. We calculate the exchangecorrelation induced band gap renormalization (BGR) as a function of the electron-hole plasma density and the quantum wire width. The calculated BGR shows good agreement with existing experimental results, and the BGR normalized by the effective quasi-1D excitonic Rydberg exhibits an approximate one-parameter universality.

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supporting

confidence: 81%

Band-gap renormalization in photoexcited semiconductor quantum-wire structures in theGWapproximation

Hwang

Sarma

1998

Phys. Rev. B

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“…This is surprising because one expects a strongly density-dependent "red shift" in the peak due to the exchange-correlation induced band gap renormalization (BGR) (i.e. a density-dependent shrinkage of the fundamental band gap due to electron and hole self-energy corrections), which should vary strongly as a function of the photoexcited electron-hole density [7][8][9]. This striking lack of any dependence of the observed photoluminescence peak energy on the photoexcitation density has led to the suggestion [1,2] that the observed quantum wire photoluminescence may be arising entirely from an excitonic (as opposed to an electron-hole plasma (EHP)) recombination mechanism, and the effective excitonic energy is, for unknown reasons, a constant (as a function of carrier density) in 1D quantum wires.…”

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confidence: 99%

Many-Body Renormalization of Semiconductor Quantum Wire Excitons: Absorption, Gain, Binding, and Unbinding

Sarma

Wang

2000

Phys. Rev. Lett.

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We consider theoretically the formation and stability of quasi-one dimensional many-body excitons in GaAs quantum wire structures under external photoexcitation conditions by solving the dynamically screened Bethe-Salpeter equation for realistic Coulomb interaction. In agreement with several recent experimental findings the calculated excitonic peak shows very weak carrier density dependence upto (and even above) the Mott transition density, nc ∼ 3 × 10 5 cm −1 . Above nc we find considerable optical gain demonstrating compellingly the possibility of one-dimensional quantum wire laser operation.PACS numbers: 71.35.Cc; 78.66.Fd; 73.20.Dx An exciton, the bound Coulombic ("hydrogenic") state between an electron in the conduction band and a hole in the valence band, is an (extensively studied) central concept in semiconductor physics. Recent interest has focused on low dimensional excitons in artificially structured semiconductor quantum well or wire systems where carrier confinement may substantially enhance the excitonic binding energy leading to novel optical phenomena. In this Letter we consider the formation, stability, and optical properties of one dimensional (1D) excitons in semiconductor quantum wires, a problem which has attracted a great deal of recent experimental [1][2][3] and theoretical [4-6] attention. Our motivation has been a number of recent puzzling experimental observations [1,2], which find the photoluminescence emitted from an initially photoexcited semiconductor quantum wire plasma to be peaked essentially at a constant energy independent of the magnitude of the photoexcitation intensity. This is surprising because one expects a strongly density-dependent "red shift" in the peak due to the exchange-correlation induced band gap renormalization (BGR) (i.e. a density-dependent shrinkage of the fundamental band gap due to electron and hole self-energy corrections), which should vary strongly as a function of the photoexcited electron-hole density [7][8][9]. This striking lack of any dependence of the observed photoluminescence peak energy on the photoexcitation density has led to the suggestion [1,2] that the observed quantum wire photoluminescence may be arising entirely from an excitonic (as opposed to an electron-hole plasma (EHP)) recombination mechanism, and the effective excitonic energy is, for unknown reasons, a constant (as a function of carrier density) in 1D quantum wires. This, however, introduces a new puzzle because one expects the excitonic level to exhibit a "blue shift" (i.e. an increase) as a function of carrier density as the Coulomb interaction weakens due to screening by the finite carrier density leading to a diminished excitonic binding energy. Thus the only way to understand the experimental observation is to invoke a near exact cancelation between the red-shift arising from the self-energy correction induced BGR and the blue-shift arising from screening induced excitonic binding weakening. In this Letter, focusing on the photoexcited quasi-equilibrium regime, we provi...

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“…With increasing the electrical pumping a broadening of the spectra and a red shift is observed. The broadening on the high energy side is due to band filling whereas the red-shift indicates the occurrence of band gap renormalization [3,4] and local sample heating at the highest applied currents. The dotted lines on the spectra represent the energy positions of the interband transitions obtained by a Gaussian deconvolution of the spectra.…”

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confidence: 99%

Electro-optic processes in InGaAs/GaAs quantum wires grown by MBE on patterned substrates

Rinaldi

DeVittorio

Cingolani

et al. 1997

Superlattices and Microstructures

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Band-gap renormalization in quantum wires

Cited by 52 publications

References 19 publications

Band-gap renormalization in photoexcited semiconductor quantum-wire structures in theGWapproximation

Band-gap renormalization in photoexcited semiconductor quantum-wire structures in theGWapproximation

Many-Body Renormalization of Semiconductor Quantum Wire Excitons: Absorption, Gain, Binding, and Unbinding

Electro-optic processes in InGaAs/GaAs quantum wires grown by MBE on patterned substrates

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