Randomness extraction from Bell violation with continuous parametric down conversion

报告题目:Randomness extraction from Bell violation with continuous parametric down conversion

报告人: Lijiong Shen Centre for Quantum Technologies, National University of Singapore,
 3 Science Drive 2, Singapore, 117543
报告摘要: Quantum entanglement provides sources of randomness that can be certified as being
 uncorrelated to any outside process or variable. Certified private randomness can be extracted
by a system that shows a violation of a Bell inequality. The randomness extraction rate depends 
on the observed violation and on the repetition rate of the Bell test. Photonic systems 
generally show a small violation, but thanks to their high repetition rate it is possible to
obtain high randomness generation rate.In this work, polarization-entangled photon pair 
generated by spontaneous parametric downconversion(SPDC), together with near-unit detection 
efficiency transition-edge sensors are used to demonstrate a detection loophole-free Bell 
violation. We pump the source continuously and organize detection events in uniform time
bins. We demonstrate that the observed violation and randomness generation rates depend on the 
time bin length. We calculated a randomness generation rates are in the order of hundreds of 
random bits per second.
报告人简介:Lijiong Shen obtained his Bachelor degree in Optical Information Technology and 
second Bachelor degree in International Economy and Trade in 2014 from the Suzhou University, 
China. Then he went to the National University of Singapore (NUS) to pursue his master degree 
in applied physics. After obtained his master degree in 2015, he joined the Centre for quantum 
technologies in NUSfor his PhD in quantum optics until now.His recent research is mainly on the 
Device-independent quantum random number generator,High-efficiency superconducting single-photon
detector and Secure Clock syntonization based on entangled 
photon pairs.