Photoionization Cross Section in Low-Dimensional Systems

Abstract

A theoretical investigation of the effects of the parabolic, shifted parabolic, hill-like, and cup-like parabolic confining electric potentials on photoionization cross section (PCS) in a spherical quantum dot is presented. Each of the parabolic potentials is superimposed on an infinite spherical square quantum well (ISSQW) potential. The parabolic potential blueshifts the peaks of the PCS, while the shifted parabolic potential causes a redshift. As the so-called strength of cup-like parabolic potential is increased, the peak of the PCS becomes redshifted for the s ! p transition, but blueshifted for the p ! d, d ! f (and so forth) transitions. On the contrary, an increase in the strength of the hill-like parabolic potential blueshifts peaks of the PCS for s ! p transitions, while it redshifts those of transitions between higher states. Keywords: photoionization cross section, confining electric potential, spherical quantum dot, hydrogenic impurity 1.