%0 Journal Article %A Sara Felloni and Giuliano Strini %D 2009 %J International Journal of Nuclear and Quantum Engineering %B World Academy of Science, Engineering and Technology %I Open Science Index 33, 2009 %T Entanglement-based Quantum Computing by Diagrams of States %U https://publications.waset.org/pdf/15942 %V 33 %X We explore entanglement in composite quantum systems and how its peculiar properties are exploited in quantum information and communication protocols by means of Diagrams of States, a novel method to graphically represent and analyze how quantum information is elaborated during computations performed by quantum circuits. We present quantum diagrams of states for Bell states generation, measurements and projections, for dense coding and quantum teleportation, for probabilistic quantum machines designed to perform approximate quantum cloning and universal NOT and, finally, for quantum privacy amplification based on entanglement purification. Diagrams of states prove to be a useful approach to analyze quantum computations, by offering an intuitive graphic representation of the processing of quantum information. They also help in conceiving novel quantum computations, from describing the desired information processing to deriving the final implementation by quantum gate arrays. %P 736 - 746