Optimal realization of the transposition maps
Buscemi, F, D'Ariano, G M, Perinotti, P, Sacchi, M F · CERN Document Server (European Organization for Nuclear Research) · 2003
We solve the problem of achieving the optimal physical approximation of the transposition for pure states of arbitrary quantum systems for finite and infinite dimensions. A unitary realization is also given for any finite dimension, which provides the optimal quantum cloning map of the ancilla as well.