Probabilistic Cloning and Identification of Linearly Independent Quantum States

摘要: We construct a probabilistic quantum cloning machine by general unitary-reduction operation. With postselection of the measurement results, yields faithful copies input states. It is shown that states secretly chosen from certain set $\$=\left\{\left| \Psi_1\right> ,\left| \Psi_2\right> ,... \Psi_n\right> \right\} $ can be probabilistically cloned if and only $% \left| \Psi_1\right>$, $\left| \Psi_2\right>$, $... ,$ \Psi_n\right>$ are linearly-independent. derive best possible efficiencies. Probabilistic has close connection with problem identification states, which type $n+1$ outcome on $n$ linearly independent The optimal efficiencies for this obtained.