Intrication, complementarity and decoherence : from thought experiments to quantum information

The manipulation of simple microscopic objects (atoms, molecules, pilotons, etc.) and the generalization of these experiments to increasingly complex mesoscopic systems is one of the most dynamic areas of quantum physics today. These " thought-experiments " have become reality, shedding new light on the fundamental concepts of the theory. These studies are also stimulated by the theoretical development of quantum information processing, itself largely influenced by classical information concepts : simple quantum systems (at two levels) can be considered as carriers of " bits " of quantum information (qubits), and their manipulation makes it possible in principle to accomplish tasks impossible with classical bits.