Electronic states in double quantum well-wires with potential W-profile: combined effects of hydrostatic pressure and electric field

摘要

Within the framework of the effective mass and parabolic band approximations and using a variational procedure, a detailed theoretical study of the combined effects of hydrostatic pressure and in-growth direction applied electric field on the electronic states and binding energy of a donor impurity in a GaAs–(Ga,Al)As coupled double quantum well-wires is presented. The particular situation of W-shaped confining potential profile is analyzed. The results obtained show that the energy for the first confined electron states as well as the impurity binding energy bear strong dependences with the hydrostatic pressure, the strength of the applied electric field, and the shape of the confining potential barriers. In the case of the electron states, it is observed that their energies are increasing (decreasing) functions of the potential-shape-related -parameter (hydrostatic pressure). It is also found that, in the high hydrostatic pressure regime (25 kbar in this work), the binding energy of a donor impurity decreases with the pressure and the effects of hydrostatic pressure on the potential barriers are predominant over the effects of hydrostatic pressure on the GaAs static dielectric constant. It is shown that the binding energy can increase or decrease depending on the combined effects of the applied electric field and the dimensions of the transversal section of the coupled quantum well wires.