Today’s computers are “classical” computers, they use binary logic based on bits equal to 0 or 1. New types of computers, called quantum computers, would be based on quantum bits called “qubits”, the quantum state of which can be any linear superposition of 0 and 1 states. This would enable to make the same calculation on a great number of values – some sort of super parallelism enabled by quantum mechanics [see for instance: http://www.larecherche.fr/content/recherche/article?id=21554 or http://fr.wikipedia.org/wiki/Ordinateur_quantique ].
We are hence looking for the appropriate candidate for these qubits. Among the possibilities, we find superconducting circuits based on Josephson junctions.
