Abstract
This chapter starts with an overview of semiconductor quantum dots (QDs). Excitons and biexcitons, their importance to the optical response of single QDs, are briefly discussed. A simple model used to successfully explain many experiments in various QD systems is discussed. Semiconductor QDs represent the simplest nanostructures where the 3D quantum confinement imposed on the electron and hole motion leads to strongly modified electronic and optical properties. The most remarkable feature that makes QDs so desirable for future generations of optical, electronic and quantum logic devices is their fully quantized atomic-like energy structure (although they normally contain 103-106 atoms). This chapter reviews and discusses physics of QDs based on various optical spectroscopy experiments performed at the single QD level. The discussion is focused on a particular model gallium arsenide (GaAS) QD system, in which the experimental efforts of the authors reside..Coherent preparation and manipulation of QD states are among the core elements for devices utilizing quantum phase, such as quantum computers based on optically driven QDs. Experiments show that the single QD exciton and biexciton states can be coherently manipulated in a similar way to atoms. © 2003 Elsevier Inc. All rights reserved..