Editing Quantum Cloning (section)

==Properties==
*'''Universal:''' A quantum cloning machine can be universal, meaning that it can copy all the possible input states equally and that the cloning machine is independent of initial states. 
*'''Optimal:''' A quantum cloning machine can be optimal which means that the average [[fidelity]] of the copies with the original state(s) is maximum over all the possible states and there is no better machine allowed by quantum mechanics for the same setting.
*'''Symmetric/Asymmetric:''' A symmetric quantum cloning machine produce the copies which are equally well and close to the original state(s). In other words, the fidelity of all of the copies is the same. In asymmetric cloning machines instead, the fidelity of the output cloned states are different.