Bell-inequality violation with entangled photons, free of the coincidence-time loophole

Autor(en)

Jan-Ake Larsson, Marissa Giustina, Johannes Kofler, Bernhard Wittmann, Rupert Ursin, Sven Ramelow

Abstrakt

In a local realist model, physical properties are defined prior to and independent of measurement and no physical influence can propagate faster than the speed of light. Proper experimental violation of a Bell inequality would show that the world cannot be described with such a model. Experiments intended to demonstrate a violation usually require additional assumptions that make them vulnerable to a number of “loopholes.” In both pulsed and continuously pumped photonic experiments, an experimenter needs to identify which detected photons belong to the same pair, giving rise to the coincidence-time loophole. Here, via two different methods, we derive Clauser-Horne- and Eberhard-type inequalities that are not only free of the fair-sampling assumption (thus not being vulnerable to the detection loophole), but also free of the fair-coincidence assumption (thus not being vulnerable to the coincidence-time loophole). Both approaches can be used for pulsed as well as for continuously pumped experiments. Moreover, as they can also be applied to already existing experimental data, we finally show that a recent experiment [Giustina et al., Nature (London) 497, 227 (2013)] violated local realism without requiring the fair-coincidence assumption.

Organisation(en)

Quantenoptik, Quantennanophysik und Quanteninformation

Externe Organisation(en)

Cornell University, Linköping University, Max-Planck-Institut für Quantenoptik, Österreichische Akademie der Wissenschaften (ÖAW)

Journal

Physical Review A

Band

90

Anzahl der Seiten

7

ISSN

1050-2947

DOI

https://doi.org/10.1103/PhysRevA.90.032107

Publikationsdatum

09-2014

Peer-reviewed

Ja

ÖFOS 2012

103026 Quantenoptik

Schlagwörter

ASJC Scopus Sachgebiete

Atomic and Molecular Physics, and Optics

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/4522b168-ec56-488c-a138-2e2a9b926a57