Dartmouth Events

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. Bellʼs theorem states that this
worldview is incompatible with the predictions of quantum mechanics, as is
expressed in Bellʼs 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.