Binding energy of hydrogenic donor impurity in concentric double quantum rings: Effects of geometry, hydrostatic pressure, temperature, and aluminum concentration

2013 ◽  
Vol 48 ◽  
pp. 164-170 ◽  
Author(s):  
H.M. Baghramyan ◽  
M.G. Barseghyan ◽  
C.A. Duque ◽  
A.A. Kirakosyan
2018 ◽  
Vol 32 (11) ◽  
pp. 1850138 ◽  
Author(s):  
Min Hu ◽  
Hailong Wang ◽  
Qian Gong ◽  
Shumin Wang

Within the framework of effective-mass envelope-function theory, the ground state binding energy of a hydrogenic donor impurity is calculated in the InGaAsP/InP concentric double quantum rings (CDQRs) using the plane wave method. The effects of geometry, impurity position, external electric field and alloy composition on binding energy are considered. It is shown that the peak value of the binding energy appears in two rings with large gap as the donor impurity moves along the radial direction. The binding energy reaches the peak value at the center of ring height when the donor impurity moves along the axial direction. The binding energy shows nonlinear variation with the increase of ring height. With the external electric field applied along the z-axis, the binding energy of the donor impurity located at z[Formula: see text] decreases while that located at z[Formula: see text] increases. In addition, the binding energy decreases with increasing Ga composition, but increases with the increasing As composition.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Guangxin Wang ◽  
Xiuzhi Duan ◽  
Wei Chen

Using a variational method with two-parameter trial wave function and the effective mass approximation, the binding energy of a donor impurity in GaAs/AlxGa1−xAs cylindrical quantum ring (QR) subjected to an external field is calculated. It is shown that the donor impurity binding energy is highly dependent on the QR structure parameters (radial thickness and height), impurity position, and external electric field. The binding energy increases inchmeal as the QR parameters (radial thickness and height) decrease until a maximum value for a central impurity and then begins to drop quickly. The applied electric field can significantly modify the spread of electronic wave function in the QR and shift electronic wave function from the donor position and then leads to binding energy changes. In addition, results for the binding energies of a hydrogenic donor impurity as functions of the impurity position and applied electric field are also presented.


2013 ◽  
Vol 380-384 ◽  
pp. 4841-4844 ◽  
Author(s):  
Guang Xin Wang ◽  
Xiu Zhi Duan

The binding energy of a hydrogenic donor impurity in cylindrical GaAs quantum ring (QR) subjected to an external magnetic field is calculated within the effect mass approximation using variational method. The binding energy as a function of the QR size (the inner radius, the outer radius), the impurity position and the applied magnetic field is investigated. The results demonstrate that the ground state binding energy behaves as an decreasing function of the outer radius, and the magnetic field. Likewise, the binding energy is an increasing function of the inner radius. The binding energy firstly increases and then decreases with shifting the impurity ion from the internal surface of the QR to the external surface, indicating that there is a maximum.


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