Minimum-error discrimination of entangled quantum states

Lu, Y., Coish, N., Kaltenbaek, R., Hamel, D.R., Croke, S. and Resch, K.J. (2010) Minimum-error discrimination of entangled quantum states. Physical Review A: Atomic, Molecular and Optical Physics, 82(4), 042340. (doi: 10.1103/PhysRevA.82.042340)

Abstract

Strategies to optimally discriminate between quantum states are critical in quantum technologies. We present an experimental demonstration of minimum-error discrimination between entangled states, encoded in the polarization of pairs of photons. Although the optimal measurement involves projection onto entangled states, we use a result of J. Walgate et al. [Phys. Rev. Lett. 85, 4972 (2000)] to design an optical implementation employing only local polarization measurements and feed-forward, which performs at the Helstrom bound. Our scheme can achieve perfect discrimination of orthogonal states and minimum-error discrimination of nonorthogonal states. Our experimental results show a definite advantage over schemes not using feed-forward.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Croke, Dr Sarah
• Authors: Lu, Y., Coish, N., Kaltenbaek, R., Hamel, D.R., Croke, S., and Resch, K.J.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Physical Review A: Atomic, Molecular and Optical Physics
• Publisher: American Physical Society
• ISSN: 1050-2947
• ISSN (Online): 1094-1622