Using entanglement improves precision of quantum measurements

G. Mauro D'Ariano, Paoloplacido Lo Presti, Matteo G. A. Paris

Published 2001-09-08Version 1

We show how entanglement can be used to improve the estimation of an unknown transformation. Using entanglement is always of benefit, in improving either the precision or the stability of the measurement. Examples relevant for applications are illustrated, for either qubits and continuous variables