# A strong loophole-free test of local realism

Scott Glancy
Applied and Computational Mathematics Division (ACMD), ITL, NIST

Monday, September 26, 2016 15:00-16:00,
Building 225, B111
Gaithersburg
Monday, September 26, 2016 13:00-14:00,
Room 4058
Boulder

Abstract: The principle of local realism says that any physical system has pre-existing values for all possible measurements of the system, and those values depend only on events in the past lightcone of the system. Although this principle seems natural from the perspective of classical physics, it is violated by quantum theory. In this seminar, I will describe NIST's experiment demonstrating a loophole-free violation of local realism using entangled photon pairs, a goal of fundamental physics for more than 50 years. Successful execution of the experiment required development of a high-fidelity entangled-photon source, high-efficiency single-photon detectors, and new statistical analysis techniques. Using a hypothesis test, we compute p-values as small as $5.9×10^{−9}$, rejecting the hypothesis that local realism governs our experiment.

Speaker Bio: Scott Glancy received his PhD in physics from the University of Notre Dame in 2004. He then joined the ACMD working in the quantum information theory group in Boulder as a post-doc and is now a permanent staff member. His research interests include statistical analysis of quantum experiments, optical quantum information processing, relativistic quantum information, and quantum foundations.

Presentation Slides: PDF

Contact: W. Griffin

Note: Visitors from outside NIST must contact Cathy Graham; (301) 975-3800; at least 24 hours in advance.