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报告时间：2018年9月5日(星期三)，下午14:00报告地点：物理科技楼105会议室报告摘要: Quantum entanglement provides sources of randomness that can be certified as beinguncorrelated 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 timebins. 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.