Using Entanglement Improves the Precision of Quantum Measurements

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

doi:10.1103/PhysRevLett.87.270404

Using Entanglement Improves the Precision of Quantum Measurements

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

Phys. Rev. Lett. 87, 270404 – Published 12 December 2001

Abstract

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 or continuous variables.

Received 8 September 2001

DOI:https://doi.org/10.1103/PhysRevLett.87.270404

Authors & Affiliations

G. Mauro D'Ariano^1,2,3,*, Paoloplacido Lo Presti^1,†, and Matteo G. A. Paris^1,‡,§

¹Quantum Optics & Information Group, Istituto Nazionale di Fisica della Materia, Dipartimento di Fisica “A. Volta,” Università di Pavia, via Bassi 6, I-27100 Pavia, Italy
²Istituto Nazionale di Fisica Nucleare, Sezione di Pavia, Pavia, Italy
³Department of Electrical and Computer Engineering, Northwestern University, Evanston, Illinois 60208

^*Email address: dariano@unipv.it
^†Email address: lopresti@unipv.it
^‡Email address: paris@unipv.it
^§Electronic addresses: www.qubit.it, www.quantummechanics.it, www.quantumoptics.it