Electronic properties of hemispherical quantum dot/wetting layer with and without hydrogenic donor impurity

We obtain the electronic structure of an InAs hemispherical quantum dot with a wetting layer embedded in a GaAs barrier, with and without hydrogenic impurity located at the origin, using finite element method in the effective mass approximation. The binding energy is calculated as a function of the shape and size of the dot. The system is considered to interact with a weak, pulsed probe field and a strong continuous-wave control field. We obtain the expressions for the linear and nonlinear absorptions and dispersions of the probe pulse. According to results, applying the control field results in the reduction of the probe field absorption and group velocity at transparency window. Results show that as the dot size increases, the absorptions and dispersions increase and exhibit red shifts. Adding impurity to the system results in the blue shifts and the reduction of the absorptions and dispersions.