A quantum delayed-choice experiment

Alberto Peruzzo, Peter Shadbolt, Nicolas Brunner, Sandu Popescu, Jeremy L. O'Brien

Research output: Contribution to journalArticlepeer-review

185 Citations (Scopus)


Quantum systems exhibit particle- or wavelike behavior depending on the experimental apparatus they are confronted by. This wave-particle duality is at the heart of quantum mechanics. Its paradoxical nature is best captured in the delayed-choice thought experiment, in which a photon is forced to choose a behavior before the observer decides what to measure. Here, we report on a quantum delayed-choice experiment in which both particle and wave behaviors are investigated simultaneously. The genuinely quantum nature of the photon's behavior is certified via nonlocality, which here replaces the delayed choice of the observer in the original experiment. We observed strong nonlocal correlations, which show that the photon must simultaneously behave both as a particle and as a wave.

Original languageEnglish
Pages (from-to)634-637
Number of pages4
Issue number6107
Publication statusPublished - 2 Nov 2012
Externally publishedYes


Dive into the research topics of 'A quantum delayed-choice experiment'. Together they form a unique fingerprint.

Cite this