The Challenge of Optimal Quantum Cloning

The No Cloning Theorem prevents copying an unknown arbitrary quantum state. Buzek and Hillery [.()Bužek and Hillery, PRA\underline {54}(3),1844 (1996)] found ways to get around the No Cloning Theorem, using either a deterministic imperfect cloning method or a probabilistic exact cloning method. In this poster we will discuss optimal cloning procedures, such as using Optimal Symmetric Universal Quantum Cloning Machine and illustrate them with examples.