Electron–hole transition in a spherical quantum dot confined at the center of a cylindrical nano-wire: Comparison of isotropic and anisotropic effective mass

2012 ◽  
Vol 52 (4) ◽  
pp. 669-677 ◽  
Author(s):  
Gh. Safarpour ◽  
M. Barati ◽  
M. Moradi
Keyword(s):  
Quantum Dot ◽  
Effective Mass ◽  
Electron Hole ◽  
Spherical Quantum Dot ◽  
Hole Transition

The effect of spherical metallic nanoparticles on electromagnetically induced transparency in spherical quantum dots

2016 ◽  
Vol 30 (25) ◽  
pp. 1650215 ◽  
Author(s):  
A. Asgharinejad ◽  
H. R. Askari
Keyword(s):  
Quantum Dots ◽  
Quantum Dot ◽  
Effective Mass ◽  
Metallic Nanoparticles ◽  
Schrodinger Equation ◽  
Electromagnetically Induced Transparency ◽  
Metallic Nanoparticle ◽  
Central Potential ◽  
Spherical Quantum Dot ◽  
Induced Transparency

In this paper, electromagnetically induced transparency (EIT) is investigated in a GaAs spherical quantum dot (SQD) with central potential in presence of spherical metallic nanoparticle (SMNP). Solving the Schrödinger equation in effective mass, eigenfunctions and eigenvalues of SQD are obtained. By using the obtained eigenfunctions and eigenvalues, the susceptibility of SQD is found. In addition, dependence of EIT on radius of SQD and SMNP, distance between SMNP and SQD and Rabi and probe frequencies are investigated.

scholarly journals Adjustment of Terahertz Properties Assigned to the First Lowest Transition of (D+, X) Excitonic Complex in a Single Spherical Quantum Dot Using Temperature and Pressure

2021 ◽  
Vol 11 (13) ◽  
pp. 5969
Author(s):  
Noreddine Aghoutane ◽  
Laura M. Pérez ◽  
Anton Tiutiunnyk ◽  
David Laroze ◽  
Sotirios Baskoutas ◽  
...  
Keyword(s):  
Refractive Index ◽  
Quantum Dot ◽  
Energy Region ◽  
Practical Importance ◽  
High Energy ◽  
Spherical Quantum Dot ◽  
Terahertz Region ◽  
Mass Approximation ◽  
Optical Responses ◽  
Temperature And Pressure

This theoretical study is devoted to the effects of pressure and temperature on the optoelectronic properties assigned to the first lowest transition of the (D+,X) excitonic complex (exciton-ionized donor) inside a single AlAs/GaAs/AlAs spherical quantum dot. Calculations are performed within the effective mass approximation theory using the variational method. Optical absorption and refractive index as function of the degree of confinement, pressure, and temperature are investigated. Numerical calculation shows that the pressure favors the electron-hole and electron-ionized donor attractions which leads to an enhancement of the binding energy, while an increasing of the temperature tends to reduce it. Our investigations show also that the resonant peaks of the absorption coefficient and the refractive index are located in the terahertz region and they undergo a shift to higher (lower) therahertz frequencies when the pressure (temperature) increases. The opposite effects caused by temperature and pressure have great practical importance because they offer an alternative approach for the adjustment and the control of the optical frequencies resulting from the transition between the fundamental and the first excited state of exciton bound to an ionized dopant. The comparison of the optical properties of exciton, impurity and (D+,X) facilitates the experimental identification of these transitions which are often close. Our investigation shows that the optical responses of (D+,X) are located between the exciton (high energy region) and donor impurity (low energy region) peaks. The whole of these conclusions may lead to the novel light detector or source of terahertz range.

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