Separating the classical and quantum information via quantum cloning.
An application of quantum cloning to optimally interface a quantum system with a classical observer is presented; in particular, we describe a procedure to perform a minimal disturbance measurement on a single qubit by adopting a 1-->2 cloning machine followed by a generalized measurement on a single clone and the anticlone or on the two clones. Such a scheme can be applied to enhance the transmission fidelity over a lossy quantum channel.
Ricci
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M
Dipartimento di Fisica and Istituto Nazionale per la Fisica della Materia, Università di Roma La Sapienza, piazzale A. Moro 5, Rome I-00185, Italy.
Sciarrino
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F
Cerf
N J
NJ
Filip
R
R
Fiurásek
J
J
De Martini
F
F