Imaging Bell-type nonlocal behavior

• Published in: Science advances Vol. 5; no. 7; p. eaaw2563
• Main Authors: Moreau, Paul-Antoine, Toninelli, Ermes, Gregory, Thomas, Aspden, Reuben S, Morris, Peter A, Padgett, Miles J
• Format: Journal Article
• Language: English
• Published: United States American Association for the Advancement of Science 01.07.2019
• Subjects: Optics; Physics; SciAdv r-articles
• ISSN: 2375-2548; 2375-2548
• DOI: 10.1126/sciadv.aaw2563

The violation of a Bell inequality not only attests to the nonclassical nature of a system but also holds a very unique status within the quantum world. The amount by which the inequality is violated often provides a good benchmark on how a quantum protocol will perform. Acquiring images of such a fundamental quantum effect is a demonstration that images can capture and exploit the essence of the quantum world. Here, we report an experiment demonstrating the violation of a Bell inequality within observed images. It is based on acquiring full-field coincidence images of a phase object probed by photons from an entangled pair source. The image exhibits a violation of a Bell inequality with = 2.44 ± 0.04. This result both opens the way to new quantum imaging schemes based on the violation of a Bell inequality and suggests promise for quantum information schemes based on spatial variables.