title: Significant-Loophole-Free Test of Bell's Theorem with Entangled Photons.
abstract: Local realism is the worldview in which physical properties of objects exist independently of measurement and where physical influences cannot travel faster than the speed of light. Bell's theorem states that this worldview is incompatible with the predictions of quantum mechanics, as is expressed in Bell's inequalities. Previous experiments convincingly supported the quantum predictions. Yet, every experiment requires assumptions that provide loopholes for a local realist explanation. Here, we report a Bell test that closes the most significant of these loopholes simultaneously. Using a well-optimized source of entangled photons, rapid setting generation, and highly efficient superconducting detectors, we observe a violation of a Bell inequality with high statistical significance. The purely statistical probability of our results to occur under local realism does not exceed 3.74×10^{-31}, corresponding to an 11.5 standard deviation effect.
authors.affiliation: Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, Vienna 1090, Austria.|Quantum Optics, Quantum Nanophysics and Quantum Information, Faculty of Physics, University of Vienna, Boltzmanngasse 5, Vienna 1090, Austria.
authors.forename: Marissa
authors.initials: M
authors.lastname: Giustina
authors.affiliation: Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, Vienna 1090, Austria.|Quantum Optics, Quantum Nanophysics and Quantum Information, Faculty of Physics, University of Vienna, Boltzmanngasse 5, Vienna 1090, Austria.
authors.forename: Marijn A M
authors.initials: MA
authors.lastname: Versteegh
authors.affiliation: Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, Vienna 1090, Austria.|Quantum Optics, Quantum Nanophysics and Quantum Information, Faculty of Physics, University of Vienna, Boltzmanngasse 5, Vienna 1090, Austria.
authors.forename: Sören
authors.initials: S
authors.lastname: Wengerowsky
authors.affiliation: Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, Vienna 1090, Austria.|Quantum Optics, Quantum Nanophysics and Quantum Information, Faculty of Physics, University of Vienna, Boltzmanngasse 5, Vienna 1090, Austria.
authors.forename: Johannes
authors.initials: J
authors.lastname: Handsteiner
authors.affiliation: Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, Vienna 1090, Austria.|Quantum Optics, Quantum Nanophysics and Quantum Information, Faculty of Physics, University of Vienna, Boltzmanngasse 5, Vienna 1090, Austria.
authors.forename: Armin
authors.initials: A
authors.lastname: Hochrainer
authors.affiliation: Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, Vienna 1090, Austria.
authors.forename: Kevin
authors.initials: K
authors.lastname: Phelan
authors.affiliation: Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, Vienna 1090, Austria.
authors.forename: Fabian
authors.initials: F
authors.lastname: Steinlechner
authors.affiliation: Max-Planck-Institute of Quantum Optics, Hans-Kopfermann-Straße 1, 85748 Garching, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Kofler
authors.affiliation: Institutionen för Systemteknik, Linköpings Universitet, 581 83 Linköping, Sweden.
authors.forename: Jan-Åke
authors.initials: JÅ
authors.lastname: Larsson
authors.affiliation: ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Abellán
authors.affiliation: ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain.
authors.forename: Waldimar
authors.initials: W
authors.lastname: Amaya
authors.affiliation: ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain.|ICREA - Institució Catalana de Recerca i Estudis Avançats, 08015 Barcelona, Spain.
authors.forename: Valerio
authors.initials: V
authors.lastname: Pruneri
authors.affiliation: ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain.|ICREA - Institució Catalana de Recerca i Estudis Avançats, 08015 Barcelona, Spain.
authors.forename: Morgan W
authors.initials: MW
authors.lastname: Mitchell
authors.affiliation: Physikalisch-Technische Bundesanstalt, Abbestraße 1, 10587 Berlin, Germany.
authors.forename: Jörn
authors.initials: J
authors.lastname: Beyer
authors.affiliation: National Institute of Standards and Technology (NIST), 325 Broadway, Boulder, Colorado 80305, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Gerrits
authors.affiliation: National Institute of Standards and Technology (NIST), 325 Broadway, Boulder, Colorado 80305, USA.
authors.forename: Adriana E
authors.initials: AE
authors.lastname: Lita
authors.affiliation: National Institute of Standards and Technology (NIST), 325 Broadway, Boulder, Colorado 80305, USA.
authors.forename: Lynden K
authors.initials: LK
authors.lastname: Shalm
authors.affiliation: National Institute of Standards and Technology (NIST), 325 Broadway, Boulder, Colorado 80305, USA.
authors.forename: Sae Woo
authors.initials: SW
authors.lastname: Nam
authors.affiliation: Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, Vienna 1090, Austria.|Quantum Optics, Quantum Nanophysics and Quantum Information, Faculty of Physics, University of Vienna, Boltzmanngasse 5, Vienna 1090, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Scheidl
authors.affiliation: Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, Vienna 1090, Austria.
authors.forename: Rupert
authors.initials: R
authors.lastname: Ursin
authors.affiliation: Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, Vienna 1090, Austria.|Quantum Optics, Quantum Nanophysics and Quantum Information, Faculty of Physics, University of Vienna, Boltzmanngasse 5, Vienna 1090, Austria.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Wittmann
authors.affiliation: Institute for Quantum Optics and Quantum Information (IQOQI), Austrian Academy of Sciences, Boltzmanngasse 3, Vienna 1090, Austria.|Quantum Optics, Quantum Nanophysics and Quantum Information, Faculty of Physics, University of Vienna, Boltzmanngasse 5, Vienna 1090, Austria.
authors.forename: Anton
authors.initials: A
authors.lastname: Zeilinger