Polaronic effects on the collective excitation in a GaAs parabolic quantum wire

In this paper, the plasmon-longitudinal optical (LO) phonon interaction effects on the intrasubband structure factor, on the pair correlation function and on the intrasubband plasmon energy associated with the lowest subband in a GaAs parabolic quantum well wire (QWW) are investigated by varying the subband separation energy and the electronic density. The calculations are performed using the self-consistent field approximation, which includes the local-field correction within the Singwi, Tosi, Land and Sjölander (STLS) theory, at zero temperature and assuming a three-subband model where only the first subband is occupied by electrons. The theoretical results obtained via STLS theory are compared with the random phase approximation (RPA) approach results, in order to emphasize the importance of the local field corrections (LFC) for the calculation of the collective excitations in quasi-one-dimensional systems.

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SHORT-RANGE CORRELATION EFFECTS IN A POLARON GAS IN GaAs–AlGaAs QUANTUM WELL WIRES

Modern Physics Letters B ◽

10.1142/s0217984999001019 ◽

1999 ◽

Vol 13 (22n23) ◽

pp. 819-827 ◽

Cited By ~ 2

Author(s):

ANTÔNIO NEWTON BORGES ◽

FRANCISCO A. P. OSÓRIO ◽

PAULO CÉSAR MIRANDA MACHADO ◽

OSCAR HIPÓLITO

Keyword(s):

Quantum Well ◽

Short Range ◽

Rectangular Cross Section ◽

Random Phase ◽

Field Approximation ◽

Correlation Effects ◽

Short Range Correlation ◽

Electronic Density ◽

Quantum Well Wire ◽

Range Correlation

We investigate the short-range correlation effects of plasmon–phonon collective excitations in a quantum well wire by using the self-consistent field approximation theory proposed by Singwi, Tosi, Land and Sjolander [Phys. Rev.176, 589 (1968)]. In our calculation model, we consider a three-subband model with only one populated, for a rectangular cross-section quantum well wire with infinite height for the potential barrier. We have verified that by decreasing the wire width (and/or decreasing the electronic density), the local field correction effects are increased. We compare the present results with those obtained within the Random Phase Approximation throughout the paper and found that the differences between the two calculation methods are more significant for the intrasubband plasmon.

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Inter-subband structure factor for a quasi-one-dimensional polaron gas

International Journal of Modern Physics B ◽

10.1142/s0217979216502180 ◽

2016 ◽

Vol 30 (30) ◽

pp. 1650218

Author(s):

Paulo César Miranda Machado ◽

Francisco Aparecido Pinto Osório ◽

Antônio Newton Borges

Keyword(s):

Structure Factor ◽

Collective Excitation ◽

Pair Correlation ◽

Longitudinal Optical ◽

Static Structure Factor ◽

Phonon Coupling ◽

Excitation Spectra ◽

Static Structure ◽

One Dimensional ◽

Subband Structure

In this work, the collective excitation spectra of quasi-one-dimensional plasmon in a rectangular GaAs quantum wire is investigated. Our calculations are performed within the Singwi, Tosi, Land and Sjölander (STLS) self-consistent theory taking into account the plasmon–longitudinal optical (LO) phonon coupling effects. We have employed a three subband model with only the first subband occupied by electrons and we have considered intra-subband and inter-subband transitions. We show that the polaronic effects cause the appearance of dips and oscillations in the static structure factor dispersion relation, which are directly related with the oscillator strength transfer between the collective excitation energy branches. We have also observed oscillations in the pair-correlation function that are characteristic of inter-subband transitions and it denotes partial localization of the particle.

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Electronic Properties of n-type AlXGa1-XAs Alloys

MRS Proceedings ◽

10.1557/proc-744-m8.10 ◽

2002 ◽

Vol 744 ◽

Author(s):

A. Ferreira da Silva ◽

I. Pepe ◽

H. Haratizadeh ◽

P.O. Holtz ◽

C. Persson ◽

...

Keyword(s):

Experimental Data ◽

Local Field ◽

Random Phase Approximation ◽

Random Phase ◽

Phase Approximation ◽

Local Field Correction ◽

Theoretical Predictions ◽

Si Doped ◽

The Many ◽

Good Agreement

ABSTRACTWe have investigated, theoretically and experimentally, the reduced and optical bandgap shift of Si-doped AlXGa1-XAs alloys as a function of both the Al composition and the Si concentration. The calculations were carried out within a framework of the many particle random phase approximation with the Hubbard local-field correction, considering electron populations in the conduction minima located at the Γ, X and L-points of the Brillouin zone. The experimental data have been obtained by means of photoluminescence spectroscopy. The theoretical predictions are found to be in good agreement with the experimental results.

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