Electric Effect of Impurity in Square Quantum Wires

Abstract

In the presence of an electric field perpendicular to the axes of thewire, the binding energy of shallow donor impurity in finite squarequantum well wires is calculated. For different impurity positionsand aspect ratios of the wires, we investigate the Stark shift ofthe 1s-like state energy of the impurity by expanding the wavefunction into a two-dimensional Fourier series and by using thevariational scheme. It is found that the electric field breaks down thedegeneracy of the states for impurities symmetrically positioned withinthe structure and leads to red-shift or blue-shift of the impurityStark energy, respectively. Furthermore, the scaling rule of thebinding energy will not be valid for the square quantum well wire underthe applied electric field.