Skip to content

Optimal simultaneous measurements of incompatible observables of a single photon

Research output: Contribution to journalArticle

Original languageEnglish
Article number340178
Pages (from-to)257-263
Number of pages7
Issue number3
Early online date27 Feb 2019
DateAccepted/In press - 29 Jan 2019
DateE-pub ahead of print - 27 Feb 2019
DatePublished (current) - 20 Mar 2019


The ultimate limits of measurement precision are dictated by the laws of quantum mechanics. One of the most fascinating results is that joint or simultaneous measurements of noncommuting quantum observables are possible at the cost of increased unsharpness or measurement uncertainty. Many different criteria exist for determining what an “op-timal” joint measurement is, with corresponding different trade-off relations for the measurements. It is generally a nontrivial task to devise or implement a strategy that minimizes the joint-measurement uncertainty. Here, we implement the simplest possible technique for an optimal four-outcome joint measurement and demonstrate a type of optimal measurement that has not been realized before in a photonic setting. We experimentally investigate a joint-measurement uncertainty relation that is more fundamental in the sense that it refers only to probabilities and is independent of values assigned to measurement outcomes. Using a heralded single-photon source, we demonstrate quantum-limited performance of the scheme on single quanta. Since quantum measurements underpin many concepts in quantum information science, this study is both of fundamental interest and relevant for emerging pho-tonic quantum technologies.



  • Full-text PDF (submitted manuscript)

    Rights statement: This is the accepted author manuscript (AAM). The final published version (version of record) is available online via OSA at . Please refer to any applicable terms of use of the publisher.

    Submitted manuscript, 6 MB, PDF document

    Embargo ends: 27/02/20

    Request copy

    Licence: Other



View research connections

Related faculties, schools or groups