[quantum-info] IQC Seminar April 23rd

[Erin Cronin]

IQC Seminar

Tuesday, 23 April 2013 at 12:00PM
**Note Room** QNC 1502

Quantification of experimental evidence against local realism
Yanbao Zhang
University of Colorado at Boulder

Abstract:
    It is highly desirable to have reliable experimental demonstrations of violations of Bell inequalities for rejecting local realism. A potential problem is that due to statistical uctuations, a 
nite set of data points generated by a local realistic model can violate a Bell inequality. In order to statistically quantify the evidence against local realism in an experiment, one needs to compute an upper bound of the probability, according to local realism, of a violation at least as high as that observed. Such bounds also help to prove the security of quantum key distribution or certify the generation of genuine randomness.

    We propose a protocol for computing such a bound in a device- independent way. That is, the protocol works even when the prepared quantum state, measurement settings, and relevant local realistic models vary arbitrarily with time. If the prepared quantum state and measurement settings are stable over time, the computed bound is asymptotically tight with respect to the number of observations. The proposed protocol can also be adapted to any test with linear witnesses, such as tests for entanglement and system dimensionality.

    Joint work with Scott Glancy and Emanuel Knill of NIST.