Hydrogenic impurity in a coaxial quantum well wire: Effect of different masses of wires and barriers

2010 ◽  
Vol 42 (9) ◽  
pp. 2307-2313 ◽  
Author(s):  
I.F.I. Mikhail ◽  
S.B.A. El Sayed
Keyword(s):  
Quantum Well ◽  
Hydrogenic Impurity ◽  
Quantum Well Wire

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   

Product trial function for confined quantum systems

1995 ◽  
Vol 73 (1-2) ◽  
pp. 48-52 ◽  
Author(s):  
K. R. Brownstein
Keyword(s):  
Differential Equation ◽  
Quantum Well ◽  
Arbitrary Shape ◽  
Quantum Systems ◽  
Hydrogenic Impurity ◽  
Product Trial ◽  
Quantum Well Wire ◽  
Judicious Choice ◽  
Confined Quantum Systems ◽  
Shape And Size

To obtain the energy of a confined quantum system (e.g., a quantum-well wire) using the variational method, one usually uses a product ψ(r) = F(r)G(r) form for a trial wave function. The envelope function F takes care of the boundary condition (ψ = 0) by vanishing on the boundary of the confining region R while the function G can contain variational parameters for flexibility. We show that by judicious choice for F and G, the kinetic energy decouples into the sum of two terms: one associated with F and the other with G. For the particular case of a Coulomb potential (e.g., a hydrogenic impurity) we obtain (i) an expression for [Formula: see text] and (ii) a differential equation for the associated binding energy as a function of the size of the containing region R; both of these being valid for regions of arbitrary shape and size. A prediction of the differential equation is shown to agree with a published calculation for a quantum-well wire.

scholarly journals Effect of temperature on the binding energy of a shallow hydrogenic impurity in a quantum well wire

2009 ◽  
Vol 87 (11) ◽  
pp. 1159-1161 ◽  
Author(s):  
T. G. Emam
Keyword(s):  
Binding Energy ◽  
Quantum Well ◽  
Temperature Dependence ◽  
Dielectric Constants ◽  
Effect Of Temperature ◽  
Wire Radius ◽  
Hydrogenic Impurity ◽  
Quantum Well Wire ◽  
Barrier Region ◽  
Temperature Dependance

In this work, we investigate the variation of the binding energy of an on-axis hydrogenic impurity in a cylindrical semiconductor GaAsalxGa1–xAs quantum well wire (QWW) with temperature, by taking into account the temperature dependance of the electron masses and dielectric constants in the quantum well and potential barrier region as well as the temperature dependence of the barrier height. This investigation is important in understanding the role such impurities can play in determining the transport properties of such systems. The results show enhancement of the binding energy as the temperature is decreased, specially for small values of wire radius.

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