Modeling and prospects for a solid-state quantum computer

Traditional approaches to computing based on nanoelectronics will likely need to embrace quantum phenomena over the coming decade with the trend toward decreasing on-chip feature sizes. Concurrently, as resonant tunneling and singleelectron-based quantum devices become more prevalent, one can expect quantum computing and quantum information based on appropriate isolated and coupled low-dimensional semiconducting systems to attract more attention. We report on work aimed at understanding the limitations on how to implement practical quantum information systems that counter the natural effects of decoherence and offer suitable approaches to control of such systems. The emphasis in this paper is on open systems. We close the paper with some remarks on possible practical schemes for fabricating such systems and identify some of the challenges that lie ahead in realizing these schemes.