VARIATIONAL CALCULATIONS OF CHARGED EXCITONS IN GaAs QUANTUM-WELL WIRES

2006 ◽  
Vol 20 (13) ◽  
pp. 761-769
Author(s):  
JIAN-JUN LIU ◽  
YAN-XIU SUN
Keyword(s):  
Wave Function ◽  
Quantum Well ◽  
Quantum Wells ◽  
Interparticle Distance ◽  
Binding Energies ◽  
Equivalent Model ◽  
Variational Calculations ◽  
Quantum Well Wires ◽  
The Wire ◽  
Parameter Wave

The binding energy of positively and negatively charged excitons in GaAs quantum-well wires is calculated variationally as a function of the wire width by using a two-parameter wave function and a one-dimensional equivalent model. There is no artificial parameter added in our calculation. It is found that the binding energies are closely correlated to the sizes of the wire, and also that their magnitudes are greater than those in the two-dimensional quantum wells compared. In addition, we also calculate the average interparticle distance and the distribution of the wave function of exciton centre-of-mass as functions of the wires width. The results are discussed in detail.

On the scaling of exciton and impurity binding energies and the virial theorem in semiconductor quantum wells and quantum-well wires

2001 ◽  
Vol 692 ◽  
Author(s):  
M. de Leyva-Dios ◽  
L. E. Oliveira
Keyword(s):  
Wave Function ◽  
Quantum Well ◽  
Quantum Wells ◽  
Virial Theorem ◽  
Dimensional Space ◽  
Shallow Donor ◽  
Binding Energies ◽  
Bohr Radius ◽  
Semiconductor Quantum Wells ◽  
Quantum Well Wires

AbstractWe have used the variational and fractional-dimensional space approaches in a study of the virial theorem value and scaling of the shallow-donor binding energies versus donor Bohr radiusin GaAs-(Ga,Al)As semiconductor quantum wells and quantum-well wires. A comparison is made with previous results with respect to exciton states. In the case the donor ground-state wave function may be approximated by a D-dimensional hydrogenic wave function, the virial theorem value equals 2 and the scaling rule for the donor binding energy versus quantum-sized Bohr radius is hyperbolic, both for quantum wells and wires. In contrast, calculations within the variational scheme show that the scaling of the donor binding energies with quantum-sized Bohr radius is in general nonhyperbolic and that the virial theorem value is nonconstant.

Optical Properties of Excitons in Quantum Well Wires Under the Magnetic Field

2003 ◽  
Vol 10 (05) ◽  
pp. 737-743 ◽  
Author(s):  
E. Kasapoglu ◽  
H. Sari ◽  
I. Sökmen
Keyword(s):  
Magnetic Field ◽  
Quantum Well ◽  
Variational Approach ◽  
Binding Energies ◽  
Linear Absorption Coefficient ◽  
Linear Absorption ◽  
Mass Approximation ◽  
Quantum Well Wires ◽  
The Wire ◽  
The Magnetic Field

The binding energy of excitons in quantum well wires of GaAs surrounded by Ga 1-x Al x As was calculated in an effective mass approximation with the use of the variational approach. Results obtained show that the exciton binding energies depend on the sizes of the wire and the strength of the magnetic field. The exciton theory was then used to calculate the linear absorption coefficient of HH1–C1 excitons by varying the wire dimensions and magnetic field values.

Origin of Blue Shifts in Quantum-Well Wires Unrelated to Lateral Confinement

1992 ◽  
Vol 283 ◽  
Author(s):  
Anders Gustafsson ◽  
X. Liu ◽  
I. Maximov ◽  
L. Samuelson ◽  
W. Seifert
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Blue Shift ◽  
High Energy ◽  
Peak Position ◽  
Lateral Confinement ◽  
Quantum Well Wire ◽  
Quantum Well Wires ◽  
The Wire ◽  
Spectrally Resolved

ABSTRACTExperimentally observed blue shifts of the peak position of the luminescence from quantum-well-wire and -dot structures are often significantly larger than the calculated shifts induced by lateral confinement in the structures. In this work we have used high-quality InGaAsAnP multi-quantum-wells for the fabrication of wires. The quantum wells are in the range 3 to 17 monolayers (ML) nominally. The thinnest well, 3 ML, shows a clearly resolved split into two luminescence peaks from areas with a thickness difference of 1 ML. In the case of the wires, the luminescence from the thicker wells show a blue shift, as well a significant broadening. However, the thinnest well shows no blue shift, but a different ratio of the two peaks, with the high energy peak favoured in the wire case. We interpret these effects in terms of a reduced transfer of excitons from thinner to thicker areas of the well in the wire as compared to the unpattemed areas. This due to a reduction of the transfer from 2 dimensional to 1 dimensional in the wires. The peaks originating in areas of different ML thicknesses are not spectrally resolved in the thicker wells and the reduced transfer therefore results in a blue shift as well as a broadening of the luminescence peak.

Thermoelectric Power in Quantum Confined Bismuth Under Classically Large Magnetic Field

1990 ◽  
Vol 216 ◽  
Author(s):  
Kamakhya P. Ghatak ◽  
S. N. Biswas
Keyword(s):  
Magnetic Field ◽  
Quantum Dots ◽  
Quantum Well ◽  
Film Thickness ◽  
Quantum Wells ◽  
Thermoelectric Power ◽  
Large Magnetic Field ◽  
Quantum Well Wires ◽  
Electron Dispersion ◽  
Theoretical Results

ABSTRACTIn this paper we studied the thermoelectric power under classically large magnetic field (TPM) in quantum wells (QWs), quantum well wires (QWWS) and quantum dots (QDs) of Bi by formulating the respective electron dispersion laws. The TPM increases with increasing film thickness in an oscillatory manner in all the cases. The TPM in QD is greatest and the least for quantum wells respectively. The theoretical results are in agreement with the experimental observations as reported elsewhere.

Binding Energies of Excitons in Square Quantum-Well Wires in the Presence of a Magnetic Field

2004 ◽  
Vol 21 (1) ◽  
pp. 166-169 ◽  
Author(s):  
Zhang Ying-Tao ◽  
Di Bing ◽  
Xie Zun ◽  
Li You-Cheng
Keyword(s):  
Magnetic Field ◽  
Quantum Well ◽  
Binding Energies ◽  
Quantum Well Wires
Sign in / Sign up

Export Citation Format

Share Document