SignificantLoopholeFree 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 welloptimized 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.
 Publication:

Physical Review Letters
 Pub Date:
 December 2015
 DOI:
 10.1103/PhysRevLett.115.250401
 arXiv:
 arXiv:1511.03190
 Bibcode:
 2015PhRvL.115y0401G
 Keywords:

 03.65.Ud;
 42.50.Xa;
 Entanglement and quantum nonlocality;
 Optical tests of quantum theory;
 Quantum Physics
 EPrint:
 Supplementary Material is available as an arXiv ancillary file. Experimental data available on requestplease contact the corresponding authors