Bell-inequality violation with entangled photons, free of the coincidence-time loophole
2014 (English)In: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 90, no 3, 032107- p.Article in journal (Refereed) Published
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.
Place, publisher, year, edition, pages
American Physical Society , 2014. Vol. 90, no 3, 032107- p.
Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:liu:diva-111605DOI: 10.1103/PhysRevA.90.032107ISI: 000342495700001OAI: oai:DiVA.org:liu-111605DiVA: diva2:758549
Funding Agencies|Austrian Science Fund (FWF) under project CoQuS; European Commission through a Marie-Curie Fellowship [PIOF-GA-2012-329851]2014-10-272014-10-272016-08-31