SHAPE EFFECT OF SEMIMAGNETIC QUANTUM DOT ON THE BOUND MAGNETIC POLARON

2011 ◽  
Vol 10 (04n05) ◽  
pp. 665-668 ◽  
Author(s):  
A. MERWYN JASPER DE REUBEN ◽  
K. JAYAKUMAR

The effect of geometry, concentration of Mn ion and the magnetic field on the binding energy of a donor and the donor bound magnetic polaronic shift in a finite Cd 1–x1 Mn x1 Te / Cd 1–x2 Mn x2 Te Quantum Dot within the effective mass approximation is carried out employing the variational principle. The results are presented and discussed.

2009 ◽  
Vol 23 (26) ◽  
pp. 5109-5118 ◽  
Author(s):  
A. JOHN PETER

The binding energy of shallow hydrogenic impurities in parabolic GaAs/GaAlAs quantum dots is calculated as a function of dot radius in the influence of magnetic field. The binding energy has been calculated following a variational procedure within the effective-mass approximation. Calculations are presented with constant effective-mass and position dependent effective masses. A finite confining potential well with depth is determined by the discontinuity of the band gap in the quantum dot and the cladding. The results show that the impurity binding energy (i) increases as the dot radius decreases for the infinite case, (ii) reaches a peak value around 1R* as the dot radius decreases and then diminishes to a limiting value corresponding to the radius for which there are no bound states in the well for the infinite case, and (iii) increases with the magnetic field. Also it is found that (i) the use of constant effective mass (0.067 m0) is justified for dot sizes ≥ a* where a* is the effective Bohr radius which is about 100 Å for GaAs , in the estimation of ionization energy and (ii) the binding energy shows complicated behavior when the position dependent mass is included for the dot size ≤ a*. These results are compared with the available existing literatures.


2007 ◽  
Vol 21 (17) ◽  
pp. 3035-3044 ◽  
Author(s):  
A. JOHN PETER

Using a variational approach, the binding energy of shallow hydrogenic impurities in a semimagnetic parabolic quantum dot is calculated within the effective mass approximation. The binding energy is computed for Cd 1-x in Mn x in Te / Cd 1-x out Mn x out Te structures as a function of the dot size in an external magnetic field. The results show that the impurity binding energy (i) increases with the reduction in dot sizes (ii) decreases when the magnetic field is increased for a given dot and (iii) increases to a maximum value at 100 Å and then decreases as the size of the dot increases beyond 100 Å for a realistic model. Spin polaronic shifts are estimated using a mean field theory. These results are compared with the existing literatures.


2011 ◽  
Vol 25 (32) ◽  
pp. 2451-2459 ◽  
Author(s):  
U. YESILGUL ◽  
F. UNGAN ◽  
E. KASAPOGLU ◽  
H. SARI ◽  
I. SÖKMEN

The intersubband transitions and impurity binding energy in differently shaped semiconductor quantum wells under a magnetic field are calculated using a variational method within the effective mass approximation. Our calculations have revealed the dependence of the intersubband transitions and impurity binding energy on the magnetic field strength and the shape of the quantum wells.


2004 ◽  
Vol 18 (17n19) ◽  
pp. 2529-2533 ◽  
Author(s):  
XIANGHUA ZENG ◽  
JIAFENG CHANG ◽  
PENGXIA ZHOU

In this paper,the ground state energies of hydrogen-like impurity in a lens-shaped quantum dot ( GaAs / In 1-x Ga x As ) under vertical magnetic field have been discussed by using effective mass approximation and variational method. It gives that for a lens-shaped quantum dot, due to the asymmetry of the vertical and lateral bound potentials, the electronic ground state energies are related not only with the deviation distance but also with the deviation direction; for the spherical quantum dot, the ground state energy is only related with the distance of the impurity deviation, neither with vertical nor lateral deviation. And with the increasing of the magnetic field, the ground state energy is increasing.


2013 ◽  
Vol 380-384 ◽  
pp. 4837-4840
Author(s):  
Xiu Zhi Duan ◽  
Guang Xin Wang

The electron states of self-assembled rectangular quantum wires (QWRs) are investigated in detail in the presence of a magnetic field. The calculations are done in the single band effective mass approximation. We study the electron states for the magnetic fields applied along and perpendicular to the wire, taking into account the different masses of the various particles inside and outside the QWRs. The electron energy and the influence of the magnetic field are discussed in this paper.


2008 ◽  
Vol 15 (03) ◽  
pp. 201-205 ◽  
Author(s):  
E. KASAPOGLU ◽  
H. SARI ◽  
I. SOKMEN

The binding energy of a hydrogen-like impurity in an ellipsoidal parabolic quantum dot under the magnetic and electric fields have been discussed by using the effective mass approximation and the variational method. We have calculated the effects of the magnetic and electric fields on the binding energy of donor impurities in the quantum dots with different confinement potentials. We conclude that the structural confinement is very effective, and especially in the weak confinement potential case the magnetic field dependence of the donor binding energy is more pronounced.


2011 ◽  
Vol 25 (32) ◽  
pp. 2419-2425 ◽  
Author(s):  
SHI-HUA CHEN ◽  
QING-ZHOU YAO

Within the framework of the Landau–Pekar variational method we have investigated the effective mass of strong-coupling magnetopolarons in a parabolic quantum dot. The effective mass as functions of the magnetic field strength and the confinement length of the quantum dot are obtained in the Gaussian function approximation. It is shown that the effective mass increases with the increasing magnetic field strength and increases with the decrease in the size of the quantum dot (QD).


2011 ◽  
Vol 10 (04n05) ◽  
pp. 611-615 ◽  
Author(s):  
P. NITHIANANTHI ◽  
K. JAYAKUMAR

The effect of laser and magnetic field on the semiconductor–metal transition in a Cd 1-x2 Mn x2 Te / Cd 1-x1 Mn x1 Te / Cd 1-x2 Mn x2 Te quantum well has been investigated using variational principle in effective mass approximation for smaller Mn composition. The effect of non parabolicity of the conduction band has been included in our calculation. The results are presented and discussed.


1958 ◽  
Vol 36 (9) ◽  
pp. 1161-1167 ◽  
Author(s):  
R. R. Haering

The linear Zeeman effect of the 2p m = ± 1 donor states is calculated in the effective mass approximation. The resulting level splitting is independent of the longitudinal mass characterizing the ellipsoidal conduction band energy surfaces. This result is valid as long as the Zeeman splitting of the m = ±1 states is small compared to the energy difference between the 2p m = 0 and the 2p m = ± 1 states. The Zeeman pattern to be expected in germanium is plotted as a function of the angle between the magnetic field and the (100) direction.


2002 ◽  
Vol 09 (05n06) ◽  
pp. 1785-1789
Author(s):  
J. C. RODRÍGUEZ ◽  
K. FONSECA ◽  
R. R. REY-GONZÁLEZ

We calculate the absorption spectrum of a single exciton, confined in an In x Ga 1 - x As/GaAs disk-shaped quantum dot, as a function of the strength of an applied magnetic field. Exciton eigenstates are obtained by numerical diagonalization of the Hamiltonian, within the effective mass approximation. A correction in the expression of the Coulomb interaction matrix elements is verified.


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