Abstract

Recent advances in semiconductor technology have led to the ability to dimensionally confine electron motion.¹ Semiconductor configurations that limit macroscopic electron motion to two, one, and zero dimensions are known, respectively, as quantum wells, quantum wires, and quantum dots.² In each case the dimensions of confinement are of the order of the de Broglie wavelength of the electron. The quantum dot is of particular interest in that it would be the first experimental manifestation of the particle-in-a-box (PIB) problem, so familiar from any introductory course in quantum mechanics. Λ semiconductor quantum dot has discrete energy levels that can be controlled by fabrication techniques of the box dimensions, hence producing an artificial "atom” whose properties may be engineered for various purposes. However, since the electron is not, in fact, free in the dot but is moving through the semiconductor crystal lattice, the system is not quite as clean as one might like, owing to impurities, electron—photon interactions, etc.

© 1994 Optical Society of America