Discriminating single-photon states unambiguously in high dimensions

Agnew, M., Bolduc, E., Resch, K. J., Franke-Arnold, S. and Leach, J. (2014) Discriminating single-photon states unambiguously in high dimensions. Physical Review Letters, 113, 020501. (doi: 10.1103/PhysRevLett.113.020501) (PMID:25062151)

Abstract

The ability to uniquely identify a quantum state is integral to quantum science, but for nonorthogonal states, quantum mechanics precludes deterministic, error-free discrimination. However, using the nondeterministic protocol of unambiguous state discrimination enables the error-free differentiation of states, at the cost of a lower frequency of success. We discriminate experimentally between nonorthogonal, high-dimensional states encoded in single photons; our results range from dimension d=2 to d=14. We quantify the performance of our method by comparing the total measured error rate to the theoretical rate predicted by minimum-error state discrimination. For the chosen states, we find a lower error rate by more than 1 standard deviation for dimensions up to d=12. This method will find immediate application in high-dimensional implementations of quantum information protocols, such as quantum cryptography.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Franke-Arnold, Professor Sonja
• Authors: Agnew, M., Bolduc, E., Resch, K. J., Franke-Arnold, S., and Leach, J.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Physical Review Letters
• Publisher: American Physical Society
• ISSN: 0031-9007
• ISSN (Online): 1079-7114