Magnetic Field Effects on Electron Eigenstates in a Concentric Triple Quantum Ring

2010 ◽  
Vol 10 ◽  
pp. 121-130 ◽  
Author(s):  
Hojjatollah K. Salehani ◽  
Mahdi Esmaeilzadeh ◽  
Khosrow Shakouri

In this paper, the electronic eigenstates and energy spectra of a two-dimensional system formed by three concentric, coupled, semiconductor quantum rings with a perpendicular magnetic field in the presence and the absence of a single ionized hydrogenic donor impurity are studied. It is found that the magnetic field localizes the electron wave function in the inner rings. The effects of hydrogenic donor on the electronic structure of concentric triple quantum rings are investigated in the both on- and off-center configurations. It is shown that as the donor moves away from the center of the system, the ground state energy decreases monotonically, the degeneracy is lifted and the gap between the energy levels increases. Also, the binding energy of donor impurity increases with increasing magnetic field.

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.


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.


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