Optical transition rates in a cylindrical quantum wire with a parabolic and inverse parabolic electric confining potential in a magnetic field

2021 ◽  
Vol 53 (11) ◽  
Author(s):  
Moletlanyi Tshipa ◽  
Monkami Masale
Keyword(s):  
Magnetic Field ◽  
Quantum Wire ◽  
Optical Transition ◽  
Transition Rates ◽  
Confining Potential

scholarly journals Optical Transition Rates in a Cylindrical Quantum Wire with an Inverse Parabolic Potential

2019 ◽  
Vol 2 (2) ◽  
Keyword(s):  
Quantum Wire ◽  
Optical Transition ◽  
Polarized Light ◽  
Radial Distance ◽  
Electron Transition ◽  
Dipole Approximation ◽  
Transition Rates ◽  
Free Standing ◽  
Circularly Polarized Light ◽  
Quantum Numbers

Electron transition rates due to interaction with circularly polarized light incident along the axis of a free-standing solid cylindrical nanowire are evaluated in the dipole approximation. In this case, the allowed optical transitions are only those for which the azimuthal quantum numbers of the initial and final states differ by unity. The envisaged electric potential of the quantum wire is modeled as inversely parabolic in the radial distance and such that it assumes a value of zero at the surface of the nanostructure. The investigations here are on the influence of this form of the confining potential on the transition rates involving some few electrons’ states of higher radial quantum numbers, nonetheless limited to transitions only between a pair of the electron’s energy sub bands. It is found that a sweep of the strength of the potential gives rise to modulations of the optical transition rates for higher radial quantum numbers. Furthermore, an increase of the strength of this potential reduces the transition energies thus such an increase redshifts peaks of the corresponding transitions rates.

scholarly journals RESONANT RAMAN SCATTERING OF QUANTUM WIRE IN STRONG MAGNETIC FIELD

1999 ◽  
Vol 13 (17) ◽  
pp. 2275-2283 ◽  
Author(s):  
HYUN C. LEE
Keyword(s):  
Magnetic Field ◽  
Raman Scattering ◽  
Strong Magnetic Field ◽  
Coulomb Interaction ◽  
Quantum Wire ◽  
Spin Excitation ◽  
Momentum Dependence ◽  
Near Resonance ◽  
Resonant Raman ◽  
Resonant Raman Scattering

The resonant Raman scattering of a quantum wire in a strong magnetic field is studied, focused on the effect of long range Coulomb interaction and the spin–charge separation. The energy–momentum dispersions of charge and spin excitation obtained from Raman cross-section show the characteristc cross-over behaviour induced by inter-edge Coulomb interaction. The "SPE" peak near resonance in polarized spectra becomes broad due to the momentum dependence of charge velocity. The broad peak in the depolarized spectra is shown to originate from the disparity between charge and spin excitation velocity.

scholarly journals Positive and Negative Donor Impurity in an InAs/AlAs Quantum Wire

2010 ◽  
Vol 2 (3) ◽  
pp. 433
Author(s):  
N. Arunachalam ◽  
A. J. Peter
Keyword(s):  
Binding Energy ◽  
Quantum Wire ◽  
Optical Transition ◽  
Binding Energies ◽  
Impurity Level ◽  
Wire Radius ◽  
Emission Energy ◽  
Interband Optical Transition ◽  
Mass Approximation ◽  
Charged Donor

Binding energies of positive and negative charged donor impurities in an InAs/AlAs cylindrical quantum wire are investigated. Numerical calculations are performed using the variational procedure within the single band effective mass approximation. We assume that the impurity is located at the axis of the wire. The interband optical transition with and without the exciton is computed as a function of wire radius. The valence-band anisotropy is included in our theoretical model by using different hole masses in different spatial directions. Neutral shallow donors comprise a positively charged donor and a single bound electron. It is observed that (i) negative trions have a higher binding energy than positive trions, (ii) the binding energy of the heavy-hole exciton is much larger than that of the light-hole exciton due to different hole mass values (iii) the exciton binding energy and the interband emission energy are both increased when the radius of the cylindrical quantum wire is decreased and (iv) the effect of exciton influences the interband emission energy. Our results are in good agreement with the recent published results. Keywords: Quantum wire; Impurity level; Binding energy; Excitons. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i3.4715                 J. Sci. Res. 2 (3), 433-441 (2010)  

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