In this work we present a calculation of the intradonor 1s-2p+ transition energies for an impurity donor present in a GaAs-AlGaAs Double Quantum Well structure as a function of an applied external magnetic field. In our calculation the impurity energy levels were obtained from a variational method by choosing a Gaussian trial wave function, and the energy corrections due to the polaronic effect were included by second order perturbation theory IWBPT as modified by Cohn, Larsen and Lax. We have considered only the GaAs bulk LO phonon in the electron-phonon coupling. A very good agreement between the theoretical and experimental results for a DQW consisting of two 100 Å well widths separated by a 100 Å potential barrier width was obtained.

In this work we have studied the electron LO phonon interaction on the pair-correlation function g(x) and its dependence on the electronic density for a GaAs-AlGaAs rectangular quantum wire within the random-phase approximation (RPA). We assumed two different values of the wire width. As negative non-physical results are found for lower electronic densities and small interparticle separations in the RPA approach, we have delimited the regions where the RPA approach cannot be used for the calculation of the Q1D electron gas collective excitation.

The ground state intrasubband pair-correlation function for a quasi-one-dimensional electron gas confined in a GaAs-Al xGa1-xAs parabolic quantum well wire within the Random-Phase Approximation (RPA) is calculated. We have considered two wires with subband energies separation homega = 2:0 meV and homega = 2:5 meV. The dependence of the pair-correlation function on the electronic density was studied and the regions where the RPA approach cannot be used were precisely determined.

We have investigated the electronic structure of Cd1_xMn xTe parabolic quantum wells and half-parabolic quantum wells heterostructures in the envelope function approximation using the k · p method. We have considered an external magnetic field applied in two different configurations: in the plane of the layer and in the growth direction. The confined states have been calculated taking into account the effective mass dependence of the Mn concentration and the strain effects. In this work we analyze the giant Zeeman splitting due to applied magnetic fields and we havecompared the energies of the excitonic transitions hh (lh) ->el for the magnetic field in the two considered configurations. Comparison of our results for the half-parabolic quantum wells with available experimental data is made.