Hydrostatic pressure, impurity position and electric and magnetic field effects on the binding energy and photo-ionization cross section of a hydrogenic donor impurity in an InAs Pöschl-Teller quantum ring

2011 ◽  
Vol 84 (2) ◽  
pp. 265-271 ◽  
Author(s):  
M. G. Barseghyan ◽  
M. E. Mora-Ramos ◽  
C. A. Duque
Keyword(s):  
Cross Section ◽  
Ionization Cross Section ◽  
Quantum Ring ◽  
Magnetic Field Effects ◽  
Donor Impurity ◽  
Ionization Cross ◽  
Hydrogenic Donor Impurity ◽  
Hydrogenic Donor ◽  
Electric And Magnetic Field ◽  
Photo Ionization

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
Keyword(s):  
Magnetic Field ◽  
Energy Levels ◽  
Quantum Ring ◽  
Dimensional System ◽  
Magnetic Field Effects ◽  
Donor Impurity ◽  
Quantum Rings ◽  
Hydrogenic Donor Impurity ◽  
Hydrogenic Donor ◽  
The Magnetic Field

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.

The photo-ionization cross-section of neon

1953 ◽  
Vol 220 (1140) ◽  
pp. 71-76 ◽  
Keyword(s):  
Cross Section ◽  
Ionization Cross Section ◽  
Wave Length ◽  
Grazing Incidence ◽  
Absorption Coefficients ◽  
Ionization Cross ◽  
Ionization Limit ◽  
Resonance Transitions ◽  
Photo Ionization ◽  
Dipole Length

The absorption of radiation of wave-length between 230 and 800 Å in neon was measured photometrically in a grazing incidence vacuum spectrograph. For wave-lengths longer than that corresponding to the first ionization limit the absorption coefficients were found to be zero except for photo-excitation of resonance transitions. Two sharp absorption edges were observed at 575 and 256 Å corresponding to the L 3 - and L 1 -edges respectively with a flat maximum between them. The photo-ionization cross-section at the first ionization limit was found to be 5⋅4 x 10 -18 cm 2 independent of the pressure between 50 and 500 μ ; this should be compared with the theoretical value of 5⋅8 x 10 -18 cm 2 obtained by Seaton using a dipole-length approximation. Between 575 and 400 Å the calculated and experimental curves agreed closely within the limits of measurement.

Magnetic Field Effect on the Binding Energy of a Hydrogenic Donor Impurity in Cylindrical Quantum Ring

2013 ◽  
Vol 380-384 ◽  
pp. 4841-4844 ◽  
Author(s):  
Guang Xin Wang ◽  
Xiu Zhi Duan
Keyword(s):  
Magnetic Field ◽  
Binding Energy ◽  
Magnetic Field Effect ◽  
Internal Surface ◽  
Outer Radius ◽  
Quantum Ring ◽  
Donor Impurity ◽  
Hydrogenic Donor Impurity ◽  
Inner Radius ◽  
Hydrogenic Donor

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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