Semiconductor science: the fourth generation

The author reviews work on quantum wires and quantum dots in the context of a generational framework. The first generation centered on the quantum physics of solids. The second generation saw the commercial and technical application of these new physical concepts. The third generation yielded the creation of man-made quantum systems and low-dimensional systems: inversion layers and quantum wells, superlattices, quantum wires, and quantum dots. The author discusses work on low-dimensional systems as a part of this progression. There is a clear connection between the work done during the first generation and the creation of new semiconductor structures, novel band structures, and the associated fundamental excitations. He also discusses the current directions in semiconductor research and speculates on the potential applications of semiconductor physics in the fourth generation