Recent developments in nano-optical probing have resulted in the observation of many electronic and optical properties in quantum dot structures which show great similarity to simple atomic systems including sharp line spectra. Using a novel approach to high resolution coherent nonlinear optical spectroscopy, we have probed the fully resonant nonlinear optical response which shows many features similar to simple atomic systems in contrast to higher dimensional semiconductor heterostructures(1). The measurements also show the presence of inter-dot coupling and allows us to determine numerous relaxation rates of these structures. Interestingly, the coherent nonlinear optical response also contains features not accounted for in the present models. Using these "solid state atoms", we have shown that we can extend the concepts of coherent control and wave function engineering developed in atomic/molecular systems to the limit of a single quantum dot (2) where the excitonic wave function in a single quantum dot is manipulated and monitored on a time scale short compared to the loss of quantum coherence.

References:

1. N. H. Bonadeo, et al., "Nonlinear Nano-Optics: Probing One Exciton at a Time", Phys. Rev. Lett. 81, 2759 (1998); Gammon, et al., "Fine structure splitting in the optical spectra of single GaAs quantum dots", Phys. Rev. Lett. 76, 3005 (1996)

2. Nicolas H. Bonadeo, John Erland, D. Gammon, D. Park, D.S. Katzer, D.G. Steel, "Coherent Optical Control of the Quantum State of a Single Quantum Dot" Science 282, 1473 (1998).