A5012985678- Quantum Information and Cryptography
- Quantum Computing Algorithms and Architecture
- Quantum Mechanics and Applications
- Quantum optics and atomic interactions
- Remote Sensing and Land Use
- Photonic and Optical Devices
- Mechanical and Optical Resonators
- Ecology and Vegetation Dynamics Studies
- Advanced Computational Techniques and Applications
- Environmental Quality and Pollution
- Quantum-Dot Cellular Automata
- Environmental Changes in China
- Forest, Soil, and Plant Ecology in China
- Animal Ecology and Behavior Studies
- Environmental and Agricultural Sciences
- Advanced Sensor and Control Systems
- Quantum Mechanics and Non-Hermitian Physics
- Advanced Frequency and Time Standards
- Power Systems and Technologies
- Advanced Authentication Protocols Security
- Optical Network Technologies
- Advanced Decision-Making Techniques
- Advanced Optical Sensing Technologies
- Advanced Fiber Laser Technologies
- Soil Carbon and Nitrogen Dynamics
National Institute of Metrology
2024
Beijing Academy of Quantum Information Sciences
2023
Tsinghua University
2005-2023
State Key Laboratory of Low-Dimensional Quantum Physics
2020-2021
Institute of Solid State Physics
2021
Guizhou Forestry Science Research Institute
2013-2021
Sichuan Normal University
2021
Guizhou Electric Power Design and Research Institute
2021
Lanzhou University
2019-2020
Ministry of Agriculture and Rural Affairs
2019-2020
Twin-field (TF) quantum key distribution (QKD) promises high rates over long distances to beat the rate-distance limit. Here, applying sending-or-not-sending TF QKD protocol, we experimentally demonstrate a secure that breaks absolute key-rate limit of repeaterless 509-km-long ultralow loss optical fiber. Two independent lasers are used as sources with remote-frequency-locking technique 500-km fiber distance. Practical fibers path appropriate noise filtering; and finite-key effects...
Quantum key distribution endows people with information-theoretical security in communications. Twin-field quantum (TF-QKD) has attracted considerable attention because of its outstanding rates over long distances. Recently, several demonstrations TF-QKD have been realized. Nevertheless, those experiments are implemented the laboratory, and therefore a critical question remains about whether is feasible real-world circumstances. Here, by adopting sending-or-not-sending twin-field QKD...
We present results of practical sending-or-not quantum key distribution. In real-life implementations, we need consider the following three requirements, a few different intensities rather than infinite number intensities, phase slice appropriate size infinitely small and statistical fluctuations. first show decoy-state method with only size. then give fluctuation analysis for method. Numerical simulation shows that, performance our is comparable to asymptotic case which large enough. Our...
We present improved method of sending-or-not-sending twin-field quantum key distribution (SNS TF-QKD) based on its structure and the application error rejection. %And we iteration formula for bit-flip rate survived bits after Taking finite effect into consideration with only $10^{11}$ total pulses, show that here exceeds absolute limit repeater-less whatever detection efficiency. also make comparative study different protocols numerically. It shows presents advantageous results at long...
We show that the performance of a 1310-nm quantum key distribution (QKD) system with up-conversion detectors pumped at 1550 nm is comparable or better than current 1550-nm QKD systems pump shorter wavelength. The nonlinearly-induced dark counts are reduced when wavelength light longer signal. have developed detector for system, and we experimentally study polarization sensitivity, pump-signal format, various influences on count rate. Using this in proof-of-principle experiment, achieved...
Exploring the spatiotemporal variation in vegetation net primary productivity (NPP) and evaluating impact of different drivers on NPP are vital for protection restoration Guizhou Province, which is a typical karst area China. In this study, Cox–Stuart test, linear regression spatial statistics were used to analyze Guizhou. Random Forest combined with local autocorrelation analysis was applied quantify effects eight from climate, topography, human activities growth status clusters years based...
Abstract Odd-parity error rejection (OPER), in particular the method of actively odd parity pairing (AOPP), can drastically improve asymptotic key rate sending-or-not-sending twin-field (SNS-TF) quantum distribution (QKD). However, practice, finite-key effects have to be considered for security. Here, we propose a zigzag approach verify phase-flip survived bits after OPER or AOPP. Based on this, take all efficiently calculating non-asymptotic rate. Numerical simulation shows that our here...
Abstract Small burrowing herbivores create extensive disturbances to grassland soil, which may change carbon cycling. We focused on the plateau pika ( Ochotona curzoniae ) simultaneously investigate responses of soil organic (SOC) and inorganic (SIC) stocks alpine meadows disturbance caused by this small herbivore its intensity at plot scale across five sites Qinghai‐Tibetan Plateau. The percentage bare area in a disturbed was used as proxy for pikas. Our study found that pikas reduced SIC...
We theoretically study the dynamics of typical optomechanical systems, consisting a passive optical mode and an active mechanical mode, in $\mathcal{PT}$- broken-$\mathcal{PT}$-symmetric regimes. By fully analytical treatments for average displacement particle numbers, we reveal phase diagram under different conditions various regimes both $\mathcal{PT}$-symmetry stability system. find that by appropriately tuning either gain or coupling, transitions system can be flexibly controlled. As...
We present a quantitative study of various limitations on quantum cryptographic systems operating with sifted-key rates over Mbit/s. The dead time silicon APDs not only limits the rate but also causes correlation between neighboring key bits. In addition to well-known count-rate dependent timing jitter in avalanche photo-diode (APD), faint laser sources, vertical cavity surface emission lasers (VCSELs) our system, induce significant amount data-dependent jitter. Both and are major limiting...
Recent advances in quantum key distribution (QKD) have given rise to systems that operate at transmission periods significantly shorter than the dead times of their component single-photon detectors. As continue increase rate, security concerns associated with detector can limit production rate sifted bits. We present a model high-speed QKD this identifies an optimum for system link loss and response characteristics.
A Quantum Key Distribution (QKD) network can allow multi-user communication via secure key. Moreover, by actively switching nodes, one achieve high key transmission rate for the selected nodes. However, polarization properties of different fiber path are and these also randomly drift over time. Therefore, recovery after auto-compensation during critical QKD network. In this work, we use programmable controllers to implement in We will discuss its time limitation future improvement.
We have implemented a differential-phase-shift (DPS) quantum key distribution (QKD) system at 1310 nm with superconducting single-photon detectors (SSPDs). The timing jitter of the SSPDs is very small (∼60 ps) and their dark counts rate low (<200 s−1). an ideal signal wavelength for QKD system, where signals coexist classical communication 1550 in one fiber. As element DPS QKD, Michelson interferometer was designed built using Faraday mirrors that can automatically compensate polarization...
We demonstrate a three-node QKD network that allows multiple users to share secure keys. This operates on the 850 nm and 1550 wavelengths at 1.25 Gbps clock rate. The communication route is controlled by MEMS optical switches. In this paper, we report structure experimental results including performance of switch, polarization recovery, timing alignment technology during switching. demonstration experimentally shows can be extended active multi-node networks.
We have begun to expand the NIST quantum key distribution (QKD) system into a network support secure cryptography. are starting with simple three-node network, one Alice switched between Bob1 and Bob2. To such we implemented manager that not only handles switch QKD protocol startup operations but also multiplexing synchronization of secret streams. describe function, structure interfaces this report on initial switching overhead. discuss some steps plan take optimize overhead as well hide...
This paper describes the detection of single photons, which have been transmitted through standard fiber at telecom wavelength 1310 nm. Following transmission, 1310-nm photon is up-converted to 710 nm in a periodical-poled LiNbO<sub>3</sub> (PPLN) waveguide and then detected by silicon-based avalanche photodiode (Si-APD). The overall efficiency detector 20%. We also characterized sensitivity PPLN's temperature changes. focused on noise property up-conversion detector. Without classical...
五里湖是太湖北部富营养化程度最为严重的-湖湾.从2004年1月起,为了改善水质,重建五里湖生态环境,在五里湖南岸建立了一个面积为10×10<sup>4</sup>m<sup>2</sup>示范工程试验区,采用多技术措施集成应用,开展湖泊生态重建技术研究.经过近2年的生态重建研究与实践,在示范工程试验区内建立了挺水植物、浮叶植物和沉水植物群丛23个,水生植物种类从生态重建前的零上升至15科、22属、32种,水生植物的多样性指数(Shannon-Wieher...
We study the correlation in shifted key induced by dead time of Geiger-mode avalanche photodiodes (APDs) quantum cryptographic systems. A simultaneous hold-off APDs (SHA) technique eliminates these correlations.
A complete fiber-based polarization encoding quantum key distribution (QKD) system based on the BB84 protocol has been developed at National Institute of Standard and Technology (NIST). The can be operated a sifted rate more than 4 Mbit/s over optical fiber length 1 km mean photon number 0.1. channel uses 850 nm photons from attenuated high speed VCSELs classical 1550 light normal commercial coarse wavelength division multiplexing devices. Sifted-key rates error different transmission are...
The desire for quantum-generated cryptographic key broadband encryption services has motivated the development of high-transmission-rate single-photon quantum distribution (QKD) systems. maximum operational transmission rate a QKD system is ultimately limited by timing resolution detectors and recent advances have enabled demonstration systems operating at rates well in to GHz regime. We demonstrated generated one-time-pad streaming video signal with high both free-space fiber. present an...
We propose a hybrid protocol for sending-or-not-sending (SNS) twin-field quantum key distribution: replacing the signal source by heralded single-photon (HSPS) in original SNS protocol, while decoy sources are still unchanged. Numerical simulation shows that after adopting this HSPS, performance rate and secure distance is much improved.