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. In this paper, I will discuss the recent results from my laboratory, in which we designed an experiment 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 is exceedingly unlikely, corresponding to an 11.5 standard deviation effect.
Marissa Giustina, University of Vienna, Physics
Information-Theoretic Interpretations of Quantum Mechanics: 2016 Annual Philosophy of Physics Conference
June 11-12, 2016