Entanglement of excitonic states and quantum information processing in semiconductors

A review of semiconductor-based schemes for the implementation of quantum information processing devices is presented. After recalling the fundamentals of quantum information/computation theory, we shall discuss two potential implementation schemes based on charge degrees of freedom in semiconductor nanostructures. More specifically, we shall present an all-optical implementation of quantum information processing with semiconductor macroatoms/molecules. In this case the computational degrees of freedom are interband optical transitions driven by ultrafast sequences of multicolor laser-pulse trains. As alternative approach. we shall also discuss a transport-like scheme based on ballistic electrons in coupled semiconductor quantum wires. Within such implementation strategy, we shall finally propose a relatively simple quantum gating sequence for testing Bell inequality violations in a condensed-matter environment.