HYDROGENIC IMPURITY IN QUANTUM-WELL WIRES EFFECTS OF THE IMAGE CHARGES

The ground state binding energy of a hydrogenic impurity placed on the axis of a cylindrical quantum-well wire is calculated including the effects of the image charges and the finite barrier. A variational ansatz for the wave function of the electron, that takes into account the three-dimensional behavior of the electron in small wires, has been used. Numerical results for GaAs-Ga1-xAlxAs quantum-well wires show that the effects of the image charges cause a considerable enhancement of the ground state binding energy of the impurity, especially in the case of high values of the Al composition and small wires.