Contributed Talks 2b: Experimental Talks
Tue, 15 Aug
, 14:00 - 15:20
- High-Rate Quantum Key Distribution exceeding 110Mb/sWei Li (University of Science and Technology of China); Likang Zhang (University of Science and Technology of China); Hao Tan (University of Science and Technology of China); Yichen Lu (University of Science and Technology of China); Sheng-Kai Liao (University of Science and Technology of China); Jia Huang (Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences); Hao Li (Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences); Zhen Wang (Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences); Hao-Kun Mao (Harbin Institute of Technology); Bingze Yan (Harbin Institute of Technology); Qiong Li (Harbin Institute of Technology); Yang Liu (Jinan Institute of Quantum Technology); Qiang Zhang (University of Science and Technology of China); Cheng-Zhi Peng (University of Science and Technology of China); Lixing You (Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences); Feihu Xu (University of Science and Technology of China); Jianwei Pan (University of Science and Technology of China)[Abstract]Abstract: We report a quantum key distribution system that is able to generate key at a record high key rate of 115.8 Mb/s over 10-km standard fibre. This attributes to a high-efficiency multi-pixel superconducting nanowire detector, a low-error integrated transmitter, and a fast post-processing algorithm.
- 10 GBaud Continuous-Variable Quantum Key Distribution Enabled by Integrated Photonic-Electronic ReceiversAdnan A.E. Hajomer (TECHNICAL UNIVERSITY OF DENMARK); C´edric Bruynsteen (Ghent University-imec); Ivan Derkach (TECHNICAL UNIVERSITY OF DENMARK); Nitin Jain (TECHNICAL UNIVERSITY OF DENMARK); Ulrik L. Andersen (TECHNICAL UNIVERSITY OF DENMARK); Xin Yin (Ghent University-imec); Tobias Gehring (TECHNICAL UNIVERSITY OF DENMARK)[Abstract]Abstract: Quantum key distribution (QKD) is a well-known application of quantum information theory that guarantees information-theoretically secure key exchange. While QKD systems are becoming commercially available, large-scale deployment of next-generation QKD systems requires photonic and electronic devices that are low-cost, small, and easily integrated with existing network infrastructure. Continuous variable (CV) QKD is a promising option for large-scale deployment due to its compatibility with standard telecom technology. Despite this, the secret key rates of CV-QKD systems have been limited to a few megabits per second due to the bandwidth bottleneck of the receiver and the limited symbol rate of the transmitter. Here, we present the first discrete-modulated coherent state CV-QKD system operating at a classical telecom symbol rate of 10 GBaud. This system generates keys at rates exceeding 0.7 Gb/s over a distance of 5 km and 0.3 Gb/s over a distance of 10 km while being secure against collective attacks in both the asymptotic and finite-size regimes. This is made possible by using a high-speed, co-integrated phase-diverse receiver consisting of a silicon photonics optical front-end and a custom-designed integrated transimpedance amplifier. Additionally, well-engineered digital signal processing is used for quantum state preparation and measurement. Our experiment sets a new record for secure quantum communication and paves the way for the next generation of CV-QKD systems.
- High-Rate Point-to-Multipoint QKD NetworkYiming Bian (State Key Laboratory of Information Photonics and Optical Communications, School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing 100876, China); Yan Pan (Science and Technology on Communication Security Laboratory, Institute of Southwestern Communication, Chengdu 610041, China); Yichen Zhang (State Key Laboratory of Information Photonics and Optical Communications, School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing 100876, China); Heng Wang (Science and Technology on Communication Security Laboratory, Institute of Southwestern Communication, Chengdu 610041, China); Jie Yang (Science and Technology on Communication Security Laboratory, Institute of Southwestern Communication, Chengdu 610041, China); Jiayi Dou (State Key Laboratory of Information Photonics and Optical Communications, School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing 100876, China); Yang Li (Science and Technology on Communication Security Laboratory, Institute of Southwestern Communication, Chengdu 610041, China); Wei Huang (Science and Technology on Communication Security Laboratory, Institute of Southwestern Communication, Chengdu 610041, China); Song Yu (State Key Laboratory of Information Photonics and Optical Communications, School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing 100876, China); Bingjie Xu (Science and Technology on Communication Security Laboratory, Institute of Southwestern Communication, Chengdu 610041, China); Hong Guo (State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Electronics, and Center for Quantum Information Technology, Peking University, Beijing 100871, China)[Abstract]Abstract: A coherent-state point-to-multipoint protocol is proposed to simultaneously support multiple independent quantum key distribution links between a single transmitter and massive receivers. Every prepared coherent state is measured by all receivers to generate raw keys, then processed with a secure and high-efficient key distillation method to remove the correlations between different links. The simulation results show that it can achieve remarkably high key rates even with a hundred of access points. Further, a proof-of-principle experiment with one network node and four end users has been demonstrated, where the average secret key rate of 4.1 Mbps between the transmitter and each one receiver is achieved, resulting in two orders-of-magnitude higher than previous networks. This scheme is a promising step towards a high-rate multi-user solution in a scalable quantum secure network.
- merged withPassive continuous variable quantum key distributionChenyang Li (University of Toronto); Chengqiu Hu (University of Hongkong); Wenyuan Wang (University of Hongkong); Rong Wang (University of Hongkong); Hoi-Kwong Lo (University of Toronto)[Abstract]Abstract: Passive quantum key distribution (QKD) has been proposed for discrete variable (DV) protocols to eliminate side channels in the source. Unfortunately, the key rate of passive DV-QKD protocols suffers from sifting loss and additional quantum errors. In this work, we propose the general framework of passive continuous variable quantum key distribution. Rather surprisingly, we find that the passive source is a perfect candidate for the discrete-modulated continuous variable quantum key distribution (DMCV QKD) protocol. With the phase space remapping scheme, we show that passive DMCV QKD offers the same key rate as its active counterpart. Considering the important advantage of removing side channels that have plagued the active ones, passive DMCV QKD is a promising alternative. In addition, our protocol makes the system much simpler by allowing modulator-free quantum key distribution. Finally, we experimentally characterize the passive DMCV QKD source, thus showing its practicality.Fully-Passive Twin-Field Quantum Key DistributionWenyuan Wang (University of Hong Kong); Rong Wang (University of Hong Kong); Hoi-Kwong Lo (University of Hong Kong, University of Toronto, Quantum Bridge Technologies)[Abstract]Abstract: We propose a fully-passive twin-field quantum key distribution (QKD) setup where basis choice, decoy-state preparation and encoding are all implemented entirely by post-processing without any active modulation. Our protocol can remove the potential side-channels from both source modulators and detectors, and additionally retain the high key rate advantage offered by twin-field QKD, thus offering great implementation security and good performance. Importantly, we also propose a post-processing strategy that uses mismatched phase slices and minimizes the effect of sifting. We show with numerical simulation that the new protocol can still beat the repeaterless bound and provide satisfactory key rate.