Stark Effect Dependence on Hydrogenic Impurities in GaAs Parabolic Quantum-Well Wires

摘要

The ground-state and lowest excited-state binding energies of a hydrogenic impurity in GaAs parabolicquantum-well wires(QWWs)subjected to external electric and magnetic Gelds are investigated using the finite-differencemethod within the quasi-one-dimensional effective potential model.We define an effective radius ρ_(eff)of a cylindricalQWW,which can describe the strength of the lateral confinement.For the ground state,the position of the largestprobability density of electron in x-y plane is located at a point,while for the lowest excited state,is located on acircularity whose radius is ρ_(eff).The point and circularity are pushed along the left half of the center axis of thequantum-well wire by the electric field dire ted along the right half.When an impurity is located at the point or withinthe circularity,the ground-state or lowest excited-state binding energies are the largest;when the impurity is apart fromthe point or circularity,the ground-state or lowest excited-state binding energies start to decrease.