title: Quantum tomography for measuring experimentally the matrix elements of an arbitrary quantum operation.
abstract: Quantum operations describe any state change allowed in quantum mechanics, including the evolution of an open system or the state change due to a measurement. We present a general method based on quantum tomography for measuring experimentally the matrix elements of an arbitrary quantum operation. As input the method needs only a single entangled state. The feasibility of the technique for the electromagnetic field is shown, and the experimental setup is illustrated based on homodyne tomography of a twin beam.
authors.affiliation: Theoretical Quantum Optics Group, INFM Unità di Pavia, Dipartimento di Fisica "Alessandro Volta," Università di Pavia, Pavia, Italy.
authors.forename: G M
authors.initials: GM
authors.lastname: D'Ariano
authors.forename: P
authors.initials: P
authors.lastname: Lo Presti