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Machado, Paulo César Miranda; Leite, J. R.; Osório, Francisco A. P.; Borges, Antônio Newton

doi:10.1103/physrevb.56.4128

Cited by 13 publications

(5 citation statements)

References 16 publications

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“…Quantum wires in the two-subband limit have been studied experimentally [7], and these results are in agreement with the theoretical conclusions [8]. The collective excitation has been theoretically calculated within different approximation methods, taking into account important effects such as the cross-section geometry of the wire [9,10], the potential barrier height [11], the multisubband effects [12], etc. The most common method used in the calculations has been the random-phase approximation (RPA), which gives good results when the electronic density is sufficiently high.…”

Section: Introductionsupporting

confidence: 68%

Critical Densities for the RPA Approach in Quasi-One-Dimensional Electronic Systems

Borges

Machado

Osório

et al. 2002

phys. stat. sol. (b)

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73.21.Hb The intrasubband pair-correlation function, gðxÞ, for a quasi-one-dimensional electron gas confined in a GaAs-Al x Ga 1Àx As rectangular quantum wire within the random-phase approximation (RPA) is calculated for several values of the potential barrier height and wire width. We have studied the dependence of the pair-correlation function on the electronic density, and delimited the regions where the RPA approach gives physically acceptable results, i.e. the electronic density values where gðxÞ possesses positive values for small interparticle separations. The critical density increases with increasing potential barrier height or decreasing wire width. IntroductionIn the last few years, the advent of modern semiconductor growth techniques, such as molecular beam epitaxy (MBE), made possible the fabrication of submicrometre devices. The development of such devices has led to the requirement for more accurate theoretical models for the understanding of their electronic properties. Ultrathin semiconducting wires, namely, quantum well wires (QWW), have been intensively studied. In such systems the electron gas is confined by a quasi-one-dimensional (Q1D) potential barrier that leads the electrons to have a quasi-free motion along the length of the wire, while the motion normal to the wire is quantized in two directions. The first QWW was a GaAs surrounded by Al x Ga 1Àx As fabricated by Petroff et al. [1] following a suggestion of Sakaki [2]. Recent progress in the growth of semiconductor nanostructures has made available wires of good quality. Several effects on the properties of the quasi-one-dimensional electronic gas were studied experimentally from photoluminescence and excitation photoluminescence spectroscopy [3][4][5][6].The many-body effects of the Q1D electron gas present in a QWW structure have motivated a significant number of experimental and theoretical works. Quantum wires in the two-subband limit have been studied experimentally [7], and these results are in agreement with the theoretical conclusions [8]. The collective excitation has been theoretically calculated within different approximation methods, taking into account important effects such as the cross-section geometry of the wire [9, 10], the potential barrier height [11], the multisubband effects [12], etc. The most common method used in the calculations has been the random-phase approximation (RPA), which gives good results when the electronic density is sufficiently high.

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Section: Introductionsupporting

confidence: 68%

Critical Densities for the RPA Approach in Quasi-One-Dimensional Electronic Systems

Borges

Machado

Osório

et al. 2002

phys. stat. sol. (b)

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“…2 [17]. In that work, a comparison between the results for S 0 (q x ) calculated within the RPA approach and within the STLS theory, for a GaAs QWW is presented and the authors showed that the inclusion of the LFC effect beyond RPA does not change qualitatively the shape of the structurefactor dispersion relation, but only the values of S 0 (q x ).…”

mentioning

confidence: 95%

“…More recently, the local field correction (LFC), beyond the RPA approach, within the Singwi, Tosi, Land, and Sjolander (STLS) self-consistent field theory [12], has been used to theoretically investigate the collective properties of an electron gas confined in GaAs semiconductor heterostructures such as heterojunctions [13,14], quantum wells [15], and QWW [16][17][18][19]. In these works the electronic correlations were studied and the plasmon dispersion energies, the pair correlation function and the structure factor were calculated taking into account several effects such as electronic densities, layer thickness, finite height of the potential confinement, geometric form, image charges, etc.…”

mentioning

confidence: 99%

Correlation effects for a quasi‐one‐dimensional polaron gas

Machado

Borges

Osório

2010

Physica Status Solidi (b)

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, Phone: þ55 62 3209 6400, Fax: þ55 62 3521 1806, Web: www.eee.ufg.brIn this work, we investigate the plasmon-LO phonon interaction effects on the intrasubband structure factor, electron-electron effective potential, and plasmon energy associated with the lowest subband in a GaAs-AlGaAs rectangular quantum-well wire (QWW) as a function of the electronic density. Our calculations are performed using the self-consistent field approximation, which includes the localfield correction (LFC) within the Singwi, Tosi, Land, and Sjolander (STLS) theory, at zero temperature and assuming a three-subband model, where only the first subband is occupied by electrons. We report for the first time dips in the structure factor spectra as a function of the quasi-one-dimensional (Q1D) plasmon-LO phonon wavevector that are directly related with the resonant split of the collective excitation energy into two branches due to the polaronic effects.

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“…In the mean-field approximation, the RPA generalized response function of the system can be written as [12] P.C.M. Machado et al…”

Section: Theorymentioning

confidence: 99%

“…The many-body effects of a quasi-one-dimensional (Q1D) electron gas present in a quantum well wire (QWW) structure have motivated a significant number of works [7][8][9][10][11][12]. The most common method used in theoretical works has been the random-phase approximation (RPA).…”

Section: Introductionmentioning

confidence: 99%

The effects of the plasmon-LO phonon interaction on the critical densities of RPA approach in a quasi-one-dimensional system

Machado¹,

Osório²,

Borges³

2006

Braz. J. Phys.

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In this work we have studied the electron LO phonon interaction on the pair-correlation function g(x) and its dependence on the electronic density for a GaAs-AlGaAs rectangular quantum wire within the random-phase approximation (RPA). We assumed two different values of the wire width. As negative non-physical results are found for lower electronic densities and small interparticle separations in the RPA approach, we have delimited the regions where the RPA approach cannot be used for the calculation of the Q1D electron gas collective excitation.

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Collective excitation inGaAs−Alx

Cited by 13 publications

References 16 publications

Critical Densities for the RPA Approach in Quasi-One-Dimensional Electronic Systems

Critical Densities for the RPA Approach in Quasi-One-Dimensional Electronic Systems

Correlation effects for a quasi‐one‐dimensional polaron gas

The effects of the plasmon-LO phonon interaction on the critical densities of RPA approach in a quasi-one-dimensional system

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