Imprinting complete information about a quantum channel on its output state.
We introduce a novel property of bipartite quantum states, which we call faithfulness, and we say that a state is faithful when acting with a channel on one of the two quantum systems; the output state carries complete information about the channel. The concept of faithfulness can also be extended to sets of states, when the output states altogether carry a complete imprinting of the channel. Measures of degrees of faithfulness are proposed.
D'Ariano
Giacomo Mauro
GM
Quantum Optics and Information Group, Istituto Nazionale di Fisica della Materia, Unità di Pavia and Dipartimento di Fisica A. Volta, via Bassi 6, I-27100 Pavia, Italy. dariano@unipv.it
Lo Presti
Paoloplacido
P