0000000000200783
AUTHOR
El Mustapha Feddi
showing 4 related works from this author
On the anomalous Stark effect in a thin disc-shaped quantum dot
2010
The effect of a lateral external electric field F on an exciton ground state in an InAs disc-shaped quantum dot has been studied using a variational method within the effective mass approximation. We consider that the radial dimension of the disc is very large compared to its height. This situation leads to separating the excitonic Hamiltonian into two independent parts: the lateral confinement which corresponds to a two-dimensional harmonic oscillator and an infinite square well in the growth direction. Our calculations show that the complete description of the lateral Stark shift requires both the linear and quadratic terms in F which explains that the exciton possess nonzero lateral dipo…
Magnetic properties of exciton trapped by an off-center ionized donor in single quantum dot
2021
Abstract It is known that the lines of exciton (X) and exciton trapped by an ionized donor ( D + , X ) are often very close which makes very difficult their experimental identification. In order to facilitate their distinction in spherical quantum dots, we investigate the effect of an applied magnetic field studying the binding energy of the complex ( D + , X ) as function of dot size and the ionized donor position. Our calculation is using a variational approach taking into account the interactions between all charge carriers. Our results show that the complex is more sensitive to the magnetic field than the exciton and that the energy of the exciton is not sufficiently affected when the i…
Magnetic field and dielectric environment effects on an exciton trapped by an ionized donor in a spherical quantum dot
2017
Abstract Magnetic field and host dielectric environment effects on the binding energy of an exciton trapped by an ionized donor in spherical quantum dot are investigated. In the framework of the effective mass approximation and by using a variational method, the calculations have been performed by developing a robust ten-terms wave function taking into account the different inter-particles correlations and the distortion of symmetry induced by the orientation of the applied magnetic field. The binding and the localization energies are determined as functions of dot size and magnetic field strength. It appears that the variation of magnetic shift obeys a quadratic law for low magnetic fields…
Lateral induced dipole moment and polarizability of excitons in a ZnO single quantum disk
2013
The lateral Stark shift of an exciton confined in a single ZnO quantum thin disk of radius R was calculated using a variational approach within the two bands effective mass approximation. It is shown that the exciton has a non negligible induced dipole moment when an external electric field is applied mainly for electron-hole separation below to the 3D excitonic Bohr radius. The behavior of the exciton lateral Stark shift proves the existence of an important correlation between the polarizability and the induced dipole moment.