TABLE OF CONTENTS Michael E. Flatt
Department of Physics and Astronomy and Optical Science and Technology Center,
The University of Iowa, Iowa City, IA
Computers have achieved a remarkable degree of sophistication, permeating almost all aspects of human activity. It is reasonable to ask, therefore, what a new paradigm of computation might offer to surpass the current one. Over the last decade the justification for hypothetical "quantum computers" has been constructed step by step. This justification includes the development of quantum algorithms, the construction of quantum error correction procedures, and the identification of model physical processes that could be employed in an actual quantum computer. The properties of electron and nuclear spin in semiconductor nanostructures now appear well suited for use in quantum computers. Control of the properties of an individual spin touches the central questions of quantum measurement theory, and from a practical perspective will require nanofabricated structures in which the spin can reside, and within which the spin can be manipulated.
In this chapter we shall begin with the desirable properties of quantum computers, to motivate the (considerable) effort that will be required for their construction. The focus will then shift to the physical requirements of any system for quantum computation, and the role of nanoscience in fulfilling these requirements. Turning then to the properties of spin, possible physical realizations of the elements of quantum...
