scholarly journals Diamagnetic Susceptibility of a Confined Donor in a Quantum Dot with Different Confinements

2009 ◽  
Vol 1 (2) ◽  
pp. 200-208 ◽  
Author(s):  
A. J. Peter ◽  
J. Ebenezar
Keyword(s):  
Quantum Dot ◽  
Quantum Well ◽  
Harmonic Oscillator ◽  
Diamagnetic Susceptibility ◽  
Binding Energies ◽  
Hydrogenic Impurity ◽  
Mass Approximation ◽  
Quantum Well Wire ◽  
Hydrogenic Donor ◽  
System Geometry

The binding energies of shallow hydrogenic impurity in a GaAs/GaAlAs quantum dot with spherical confinement, harmonic oscillator-like and rectangular well-like potentials are calculated as a function of dot radius using a variational procedure within the effective mass approximation. The calculations of the binding energy of the donor impurity as a function of the system geometry have been investigated. A comparison of the eigenstates of a hydrogenic impurity in all the confinements of dots is discussed in detail.  We have computed and compared the susceptibility for a hydrogenic donor in a spherical confinement, harmonic oscillator-like and rectangular well-like potentials for a finite QD and observe a strong influence of the shape of confining potential and geometry of the dot on the susceptibility. Keywords: Quantum dot; Quantum well wire; Quantum well; Diamagnetic susceptibility; Donor impurity. © 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v1i2.1184   

EFFECT OF LASER ON THE NONPARABOLICITY OF THE CONDUCTION BAND AND HYDROGENIC IMPURITY STATES IN A SEMICONDUCTOR QUANTUM WELL

2011 ◽  
Vol 25 (13) ◽  
pp. 1785-1790 ◽  
Author(s):  
A. MERWYN JASPER D. REUBEN ◽  
P. NITHIANANTHI ◽  
C. RAJA MOHAN ◽  
K. JAYAKUMAR
Keyword(s):  
Quantum Well ◽  
Conduction Band ◽  
Binding Energies ◽  
Hydrogenic Impurity ◽  
Mass Approximation ◽  
Hydrogenic Donor ◽  
Semiconductor Quantum Well ◽  
Finite Barrier ◽  
Donor States ◽  
Limiting Values

The effect of laser on the nonparabolicity of the conduction band for hydrogenic donor states like 1s, 2s, 2p± and 2p0 in a GaAs/Al x Ga 1-x As quantum well have been computed in a finite barrier model using variational principle in the effective mass approximation. The limiting values of the ground state and few excited state binding energies for a laser dressed-donor have been obtained. The results are presented and discussed.

INFLUENCE OF PRESSURE ON THE DIAMAGNETIC SUSCEPTIBILITY OF HYDROGENIC DONOR IN SOME LOW-LYING EXCITED STATES IN A QUANTUM WELL

2007 ◽  
Vol 06 (01) ◽  
pp. 37-40 ◽  
Author(s):  
P. NITHIANANTHI ◽  
K. JAYAKUMAR
Keyword(s):  
Hydrostatic Pressure ◽  
Quantum Well ◽  
Effective Mass ◽  
Excited States ◽  
Diamagnetic Susceptibility ◽  
Mass Approximation ◽  
X Band ◽  
Hydrogenic Donor ◽  
Band Mixing ◽  
Band Crossing

The influence of Γ–X band crossing due to the applied hydrostatic pressure on the diamagnetic susceptibility (χ dia ) of a donor in low-lying excited states like 2s, 2p0, 2p± in a GaAs / Al x Ga 1-x As Quantum Well has been investigated in the effective mass approximation by considering the nonparabolicity of the conduction band. We notice that the effect of Γ–X band mixing is significant on χ dia of a donor lying in excited states. Moreover, the effect of non-parabolicity on χ dia is also predominant for lower well width region. The results are presented and discussed.

THE EFFECTS OF TEMPERATURE AND HYDROSTATIC PRESSURE ON THE DIAMAGNETIC SUSCEPTIBILITY OF A DONOR IN A QUANTUM WELL

2011 ◽  
Vol 18 (05) ◽  
pp. 147-152 ◽  
Author(s):  
U. YESILGUL ◽  
F. UNGAN ◽  
E. KASAPOGLU ◽  
H. SARI ◽  
I. SÖKMEN
Keyword(s):  
Hydrostatic Pressure ◽  
Binding Energy ◽  
Quantum Well ◽  
Effective Mass ◽  
Diamagnetic Susceptibility ◽  
Effective Mass Approximation ◽  
Mass Approximation ◽  
Hydrogenic Donor ◽  
Different Temperatures ◽  
Effects Of Temperature

Using the effective-mass approximation within a variational scheme, we have calculated the diamagnetic susceptibility and binding energy of a hydrogenic donor in a quantum well under different temperatures and hydrostatic pressure conditions. Our calculation have revealed the dependence of the diamagnetic susceptibility and the impurity binding on temperature and hydrostatic pressure.

scholarly journals Polaronic Effects of a Hydrogenic Donor Impurity in Low Dimensional Semiconductor Systems

2009 ◽  
Vol 1 (3) ◽  
pp. 422-429 ◽  
Author(s):  
A. J. Peter ◽  
N. Radhakrishnan
Keyword(s):  
Binding Energy ◽  
Quantum Dot ◽  
Quantum Well ◽  
Longitudinal Optical ◽  
Wire Radius ◽  
Donor Impurity ◽  
Donor Binding Energy ◽  
Quantum Well Wire ◽  
Hydrogenic Donor ◽  
Low Dimensional

The ground state of a polaron bound to hydrogen like donor impurity is investigated by considering the effect of bulk Longitudinal-Optical (LO) phonon. Donor binding energy of a hydrogenic donor, with the inclusion of electron-phonon interaction is computed for the low-dimensional semiconducting systems like quantum well, quantum well wire and quantum dot taking GaAs/AlxGa1-xAs systems as an example. Calculations are performed using a variational approach within the single band effective mass approximation. The results show that the polaronic effect is more pronounced for the lowest confinement. The polaronic effect enhances the donor binding energy but it diminishes when the well width, wire radius and dot radius become larger. Also the numerical calculations reveal that the influences of phonons on donor are considerable and should not be neglected especially for narrow dimensions in all the three confinements.Keywords: Donor binding energy; Polaronic effect; Quantum dot; Quantum wire; Quantum well.© 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.DOI: 10.3329/jsr.v1i3.2529            J. Sci. Res. 1 (3), 422- 429 (2009)

EFFECT OF DIELECTRIC SCREENING ON THE DIAMAGNETIC SUSCEPTIBILITY OF A DONOR IN LOW DIMENSIONAL SEMICONDUCTING SYSTEMS

2009 ◽  
Vol 23 (08) ◽  
pp. 2069-2075
Author(s):  
P. NITHIANANTHI ◽  
P. VICKRAMAN ◽  
K. JAYAKUMAR
Keyword(s):  
Quantum Dot ◽  
Variational Method ◽  
Quantum Well ◽  
Effective Mass ◽  
Diamagnetic Susceptibility ◽  
Quantum Well Wire ◽  
Dielectric Screening ◽  
Low Dimensional ◽  
Infinite Barrier ◽  
Barrier Model

The effect of spatial dielectric screening on the diamagnetic susceptibility (χ dia ) of a donor in Low Dimensional Semiconducting Systems like Quantum Well, Quantum Well Wire and Quantum Dot in the infinite barrier model has been computed and investigated within the effective mass theory using variational method. We observe that the effect of spatial dielectric screening on χ dia decreases with decrease of dimensionality of the system.

LASER INDUCED METAL INSULATOR TRANSITION THROUGH EXCITON MECHANISM IN QUANTUM WELL SYSTEMS

2009 ◽  
Vol 23 (09) ◽  
pp. 1229-1242 ◽  
Author(s):  
S. RAJASHABALA ◽  
S. S. KANMANI ◽  
K. NAVANEETHAKRISHNAN
Keyword(s):  
Laser Radiation ◽  
Quantum Well ◽  
Diamagnetic Susceptibility ◽  
Critical Concentration ◽  
Binding Energies ◽  
Insulator Transition ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Mass Approximation ◽  
Exciton Mechanism

Within the effective mass approximation, the binding energies of a Wannier exciton in a GaAs-Ga 1-x Al x As quantum well in an electric field are investigated using a variational method. The binding energiesare obtained upon illlumination by laser radiation. The binding energy decreases as the well size increases when the size of the well is beyond 50 Å. The above behavior is for a quantum well of finite confinement. We have investigated the metal-insulator transition in such a system and report the values of critical concentrations of excitons at which metal-insulator transition occurs for different well dimensions. The calculated diamagnetic susceptibility shows the catastrophic behavior at the critical concentration.

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