Stark Effect Dependence on Hydrogenic Impurities in GaAs ParabolicQuantum-Well Wires

The ground-state and lowest excited-state binding energies of ahydrogenic impurity in GaAs parabolic quantum-well wires (QWWs)subjected to external electric and magnetic fields are investigated using the finite-difference method within the quasi-one-dimensional effective potential model. We define an effective radius ρ_eff of a cylindrical QWW, which can describe the strength of the lateral confinement. For the ground state, theposition of the largest probability density of electron in x-y plane is located at a point, while for the lowest excited state, is located on a circularity whose radius is ρ_eff. The point and circularity are pushed along the left half of the center axis of the quantum-well wire by the electric field directed along theright half. When an impurity is located at the point or within the circularity, the ground-state or lowest excited-state binding energies are the largest; when the impurity is apart from the point or circularity, the ground-state or lowest excited-state binding energies start to decrease.