Invited Speaker: ''Long Distance Quantum Key Distribution Gets Simpler''

Wed, 16 Aug , 11:30 - 12:15

    Abstract: Quantum cryptography promises secure communication between two distant users. However, secure key rate of point-point quantum key distribution (QKD) is bounded by the linear rate-loss limit. Twin-field (TF) QKD can break this limit but its implementation requires global phase tracking and usually also cumbersome interferometric implementations, which are often impractical for network deployment. We remove the above shortcomings with two different solutions. In the first solution, we introduce locally generated frequency combs to stabilise an open channel, and develop a simple and versatile TF-QKD setup that does not need service fibre. In the second, we implement a simple measurement device independent (MDI) QKD with post-measurement pairing technique. We demonstrate the capability of asynchronous MDI-QKD (also named mode-pairing MDI-QKD) overcoming the linear rate-loss limit without global phase tracking.

    Bio: Dr Lai Zhou received the B.S. and Ph.D. degrees from Tsinghua University in 2013 and 2018, respectively. He was a postdoc at the University of Oxford in 2019. He joined the Beijing Academy of Quantum Information Sciences as an assistant researcher in 2020. Currently he is an associate researcher, and his research interests include long distance quantum key distribution and quantum networks.