Exciton related optical absorption in a spherical quantum dot

2014-11-10
Aksahin, Ertan
Unal, Vildan Ustoglu
Tomak, Mehmet
An exciton in a spherical quantum dot is studied analytically within the effective mass approximation. A parabolic confinement under an electric field is considered. The linear and nonlinear optical absorption coefficients are calculated within the density matrix formalism. No assumptions are made about the strength of the confinement. It is shown how the competing mechanisms of the Coulomb interaction, the confinement and the applied static electric field affect the optical absorption.
EUROPEAN PHYSICAL JOURNAL B

Suggestions

MAGNETIC-FIELD DEPENDENCE OF HYDROGENIC IMPURITY STATES IN A QUANTUM-WELL WIRE
ELSAID, M; Tomak, Mehmet (1991-02-01)
The binding energy for on-centre impurities in a rectangular quantum well wire is calculated as a function of the width of the wire and perpendicular magnetic field. The results for zero-magnetic-field cases are in perfect agreement with previous calculations.
Exciton related nonlinear optical properties of a spherical quantum dot
Aksahin, E.; Unal, V. Ustoglu; Tomak, Mehmet (2015-11-01)
The nonlinear optical properties of an exciton in a spherical quantum dot (QD) is studied analytically. The nonlinear optical coefficients are calculated within the density matrix formalism. The electronic problem is solved within the effective mass approximation. The contributions from the competing effects of the confinement, the Coulomb interaction, and the applied electric field are calculated and compared with each other. We have made no assumptions about the strength of the confinement. We concentrate...
Nonlinear optical properties of semiconductor heterostructures
Yıldırım, Hasan; Tomak, Mehmet; Department of Physics (2006)
The nonlinear optical properties of semiconductor heterostructures, such as GaAsAl/GaAs alloys, are studied with analytic and numerical methods on the basis of quantum mechanics. Particularly, second and third-order nonlinear optical properties of quantum wells described by the various types of confining potentials are considered within the density matrix formalism. We consider a Pöschl-Teller type potential which has been rarely considered in this area. It has a tunable asymmetry parameter, making it a goo...
Interacting electrons in a 2D quantum dot
Akman, N; Tomak, Mehmet (1999-04-01)
The exact numerical diagonalization of the Hamiltonian of a 2D circular quantum dot is performed for 2, 3, and 4 electrons. The results an compared with those of the perturbation theory. Our numerical results agree reasonably well for small values of the dimensionless coupling constant lambda = a/a(B) where a is the dot radius and a(B) is the effective Bohr radius. Exact diagonalization results are compared with the classical predictions, and they are found to be almost coincident for large lambda values.
Neutrino oscillations induced by spacetime torsion
Adak, M; Dereli, T; Ryder, LH (IOP Publishing, 2001-04-21)
The gravitational neutrino oscillation problem is studied by considering the Dirac Hamiltonian in a Riemann-Cartan spacetime and calculating the dynamical phase. Torsion contributions which depend on the spin direction of the mass eigenstates are found. These effects are of the order of Planck scales.
Citation Formats
E. Aksahin, V. U. Unal, and M. Tomak, “Exciton related optical absorption in a spherical quantum dot,” EUROPEAN PHYSICAL JOURNAL B, pp. 0–0, 2014, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/37331.