Theory of autoionization and photoionization in two-electron spherical quantum dots

Abstract

The two-electron resonance states of spherically symmetric artificial atoms (quantum dots) are investigated using the complex scaled full configuration-interaction method. The one-electron confining potential term of the quantum dot is presented by a Gaussian one-electron confining potential. Contrary to natural atoms, the single electron excited states of an artificial atom become resonance states for appropriately chosen external confining potential parameters. Moreover, the external confining potential of an artificial atom can be tuned to provide efficient photodetectors, which are extremely sensitive even to a weak external radiation with a specific wavelength. In order to illustrate efficiency of such a photodetector, we calculate the ionization rates corresponding to the interaction of an artificial atom with external laser field. The mechanism for photoionization through a short-lived autoionizing singly excited resonance state is discussed.