Wavelength-Multiplexed Entanglement Distribution over 10 km of Fiber
Han Chuen Lim, Akio Yoshizawa, Hidemi Tsuchida, Kazuro Kikuchi
我们报告的第一个实验演示波长复用纠缠分布。来自单个宽带光源的44个通道的高度纠缠光子对分布在10 km的光纤上。
We report the first experimental demonstration of wavelength-multiplexed entanglement distribution. 44 channels of highly-entangled photon-pairs from one single broadband source are distributed over 10 km of fiber.
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Orbital angular momentum (OAM) multiplexing provides an efficient method to improve data-carrying capacity in various quantum communication protocols. It is a precondition to distribute OAM multiplexed quantum resources in quantum channels for implementing quantum communication. However, quantum steering of OAM multiplexed optical fields and the effect of channel noise on OAM multiplexed quantum resources remain unclear. Here, we generate OAM multiplexed continuous-variable (CV) entangled states and distribute them in lossy or noisy channels. We show that the decoherence property of entangleme…
Generation of frequency multiplexed entangled single photons assisted by the entanglement
提出了一种利用混合原子系综纠缠产生频率复用纠缠单光子的方案。根据特定时序驱动写入和读取场，可以重复FME单光子的生成，直到实现成功。该光源在波分复用量子密钥分发中具有重要的应用价值。
A prerequisite for universal quantum computation and other large-scale quantum information processors is the careful preparation of quantum states in massive numbers or of massive dimension. For continuous variable approaches to quantum information processing (QIP), squeezed states are the natural quantum resources, but most demonstrations have been based on a limited number of squeezed states due to the experimental complexity in up-scaling. The number of physical resources can however be significantly reduced by employing the technique of temporal multiplexing. Here, we demonstrate an applic…
Entropy of entanglement in continuous frequency space of the biphoton state from multiplexed cold atomic ensembles
我们考虑了一个多路复用冷原子系综方案，该方案产生了一个纠缠熵可控的频率纠缠双光子态。双光子态由一个通信光子（信号）和一个红外光子（闲频）组成，通过与两个经典泵浦场的四波混频。将原子系综与频移和相移的信号光和闲频光进行复用，可以对双光子态的光谱特性进行操纵和控制。该方案通过映射出纠缠熵，为纠缠资源提供了最优配置。这为有效的长距离量子通信和量子信息处理中潜在有用的多模结构铺平了道路。
The ability to transmit quantum states over long distances is a fundamental requirement of the quantum internet and is reliant upon quantum repeaters. Quantum repeaters involve entangled photon sources that emit and deliver photonic entangled states at high rates and quantum memories that can temporarily store quantum states. Improvement of the entanglement distribution rate is essential for quantum repeaters, and multiplexing is expected to be a breakthrough. However, limited studies exist on multiplexed photon sources and their coupling with a multiplexed quantum memory. Here, we demonstrate…
The sources, which generate atom-photon quantum correlations or entanglement based on quantum memory, are basic blocks for building quantum repeaters (QRs). For achieving highly entanglement-generation rates in ensemble-based QRs, spatial-, temporal- and spectral-multimode memories are needed. The previous temporal-multimode memories are based on rephrasing mechanisms in inhomogeneous-broadened media. Here, by applying a train of multi-direction write pulses into a homogeneous-broadened atomic ensemble to induce Duan-Lukin-Cirac-Zoller-like Raman processes, we prepare up to 19 pairs of modes, …
Space-division multiplexed phase compensation for quantum communication: concept and field demonstration
针对光纤量子通信中的相位漂移问题，首次提出并现场演示了基于相邻光纤的空分复用相位补偿方案，显著降低了相位漂移并改善了量子比特错误率。
In state-of-the-art quantum key distribution (QKD) systems, the main limiting factor in increasing the key generation rate is the timing resolution in detecting photons. Here, we present and experimentally demonstrate a strategy to overcome this limitation, also for high-loss and long-distance implementations. We exploit the intrinsic wavelength correlations of entangled photons using wavelength multiplexing to generate a quantum secure key from polarization entanglement. The presented approach can be integrated into both fiber- and satellite-based quantum-communication schemes, without any ch…
High-rate generation of hybrid photon-matter entanglement remains a fundamental building block of quantum network architectures enabling protocols such as quantum secure communication or quantum distributed computing. While a tremendous effort has been made to overcome technological constraints limiting the efficiency and coherence times of current systems, an important complementary approach is to employ parallel and multiplexed architectures. Here we follow this approach experimentally demonstrating the generation of bipartite polarization-entangled photonic states across more than 500 modes…
We generated time-multiplexed degenerate optical parametric oscillator (DOPO) pulses using a nonlinear fiber Sagnac loop as a phase-sensitive amplifier (PSA) where the pump and amplified light in pump-signal-idler degenerate four-wave mixing can be spatially separated. By placing the PSA in a fiber cavity, we successfully generated more than 5,000 time-multiplexed DOPO pulses. We confirmed the bifurcation of pulse phases to 0 or $π$ relative to the pump phase, which makes them useful for representing Ising spins in an Ising model solver based on coherent optical oscillator networks. We also co…
Transmission of O-band wavelength-division-multiplexed heralded photons over a noise-corrupted optical fiber channel
我们在一个概念验证实验中将O波段的先驱光子传输到10 km的光纤上，证明了使用先驱光子来提高量子密钥分发的噪声容限的可行性。在我们的实验中，光纤信道被噪声光子破坏到这样的程度，如果我们使用衰减激光器作为光子源，则接收器处的光子信噪比< 4.0，对应于> 10.0%的量子误码率，将阻止安全密钥的有效生成。使用光子预报方案，在我们的实验中，光子信噪比被示出为> 7.8。这对应于<5.7%的量子比特错误率，这对于提取安全密钥来说已经足够了。此外，我们表明，它是可能的，将波分复用到光子预告计划，以提高整体的密钥速率。讨论并阐明了光子预言方案在抗噪声量子密钥分发中的应用前景和局限性。
Multiplexed entanglement generation over quantum networks using multi-qubit nodes
分布在几公里以上距离的量子网络将受到节点之间信息传播所需时间的限制。我们分析的协议，能够绕过这个瓶颈，采用多量子位节点和多路复用。对于每个协议，我们调查的关键网络参数，确定其性能。我们根据氮空位中心和其他有前途的网络平台的预期近期性能来模拟可实现的纠缠率。这种分析使我们能够比较在不同的制度，拟议的多路复用协议的潜力。此外，通过确定通过改进特定网络参数可能获得的收益，我们的分析表明了原型量子网络研究和开发的最有希望的途径。
Realization of a globe-spanning quantum network is a current worldwide goal, where near and long term implementations will benefit from connectivity between platforms optimized for specific tasks. Towards this goal, a quantum network architecture is herewith proposed whereby quantum processing devices based on NV$^-$ colour centers act as quantum routers and, between which, long-distance entanglement distribution is enabled by spectrally-multiplexed quantum repeaters based on absorptive quantum memories in rare-earth ion-doped crystals and imperfect entangled photon-pair sources. The inclusion…
Field-orthogonal temporal mode analysis of optical fields is recently developed for a new framework of quantum information science. But so far, the exact profiles of the temporal modes are not known, which makes it difficult to achieve mode selection and de-multiplexing. Here, we report a novel method that measures directly the exact form of the temporal modes. This in turn enables us to make mode-orthogonal homodyne detection with mode-matched local oscillators. We apply the method to a pulse-pumped, specially engineered fiber parametric amplifier and demonstrate temporally multiplexed multi-…
Optimal analysis of ultra broadband energy-time entanglement for high bit-rate dense wavelength division multiplexed quantum networks
我们展示了一个实验方法，用于测量能量-时间纠缠在近80 nm的光谱带宽在Single Shot与量子比特错误率低于0.5%。我们的方案是非常具有成本效益和有效的资源，因为它只采用一个源的纠缠光子和一个固定的不平衡干涉仪每个相位编码的分析基础。我们表明，当分析干涉仪适当不平衡时，可以得到最大的分析光谱带宽，这种策略可以直接应用于当今大多数基于能量-时间和时间仓纠缠的实验。因此，我们的计划有很大的潜力，提高比特率和减少资源开销的未来纠缠为基础的量子密钥分发系统。
Multiplexed entangled photon sources for all fiber quantum networks
量子信息科学的最终目标是建立一个全球性的量子网络，使量子资源能够在远程各方之间分布和共享。这种量子网络可以通过所有光纤元件来实现，其利用了低传输损耗、低成本、可扩展和相互光纤通信技术（例如密集波分复用）。因此，构建这种量子网络需要高质量的光纤纠缠光子源。在这里，我们报告的复用偏振和时间纠缠光子源的色散位移光纤工作在室温下。利用干涉、贝尔不等式和量子态层析技术对高质量的纠缠进行了表征。在100GHz的密集波分复用系统中，多信道对中纠缠的同时存在显示了多用户纠缠分布的巨大能力。我们的研究提供了一个通用的平台，并朝着构建全光纤量子网络迈出了第一步。
Multiplexed Entanglement of Multi-emitter Quantum Network Nodes
本文提出并实现了一种基于稀土离子耦合纳米光子腔的多发射体量子网络节点方案，通过频率擦除光子探测和实时量子前馈实现可区分171Yb离子的复用纠缠，并演示了复用纠缠提升分发速率及制备三离子W态，为可扩展量子网络奠定基础。
Quantum key distribution with continuous variables already uses advantageous high-speed single-mode homodyne detection with low electronic noise at room temperature. Together with continuous-variable information encoding to nonclassical states, the distance for secure key transmission through lossy channels can approach 300 km in current optical fibers. Such protocols tolerate higher channel noise and also limited data processing efficiency compared to coherent-state protocols. The secret key rate can be further increased by increasing the system clock rates, and, further, by a suitable freque…
High-rate multiplexed entanglement source based on time-bin qubits for advanced quantum networks
本文提出一种基于时间比特量子比特的4.09 GHz高速率复用纠缠源，通过频率复用自发参量下转换输出实现8对纠缠，可见度达99.4%，总纠缠率达3.55e6符合率/秒，为高级量子网络提供基础构建块。
Multiplexed entanglement swapping with atomic-ensemble-based quantum memories in the single excitation regime
本研究实验演示了基于原子系综量子存储器的多路复用纠缠交换，成功将两个此前未纠缠的存储器投影至纠缠态，并发度C=0.0124，成功概率比非多路复用方案提高三倍。
High-brightness fiber-based Sagnac source of entangled photon pairs for multiplexed quantum networks
基于非线性萨格纳克干涉仪的高亮度光纤源产生纠缠光子对，支持极化和能量-时间纠缠，实现高归一化亮度和高纠缠质量，适用于多路复用量子网络。
Implementation of space-division multiplexed entanglement-based quantum cryptography over multicore fiber
本文在19芯多芯光纤中实验实现空分复用的纠缠量子密钥分发，利用SPDC光子对动量相关性将偏振纠缠光子对送入不同纤芯，并在411米传输后评估6芯与12芯配置的密钥率提升。
Exploiting two interfering fields which are initially in the same temporal mode but with the spectra altered by propagating through different fibers, we characterize how the spectra of temporal modes changes with the fiber induced dispersion by measuring the fourth-order interference when the order number and bandwidth of temporal modes are varied. The experiment is done by launching a pulsed field in different temporal modes into an unbalanced Mach-Zehnder interferometer, in which the fiber lengths in two arms are different. The results show that the mode mismatch of two interfering fields, r…
Quantum networks scale the advantages of quantum communication protocols to more than just two distant users. Here we present a fully connected quantum network architecture in which a single entangled photon source distributes quantum states to a multitude of users. Our network architecture thus minimizes the resources required of each user without sacrificing security or functionality. As no adaptations of the source are required to add users, the network can readily be scaled to a large number of clients, whereby no trust in the provider of the quantum source is required. Unlike previous att…
Multiplexed ion-ion entanglement over $1.2$ kilometer fibers
本研究针对长距离量子网络纠缠分发效率低的问题，采用10个时间光子模式多路复用技术，在1.2公里光纤上实现囚禁离子节点间纠缠生成4.59倍加速与95.9±1.5%保真度，为可扩展大规模量子网络提供关键模块。
We theoretically investigate the spectral property of a biphoton state from multiplexed thermal atomic ensembles. This biphoton state originates from the cascade emissions, which can be generated by two weak pump fields under four-wave mixing condition. Under this condition, a signal photon from the upper transition, chosen in a telecommunication bandwidth, can be generated along with a correlated idler photon from the lower infrared transition. We can spectrally shape the biphoton state by multiplexing the atomic ensembles with frequency-shifted emissions, where the entropy of entanglement ca…
The use of multiplexed atomic quantum memories (MAQM) can significantly enhance the efficiency to establish entanglement in a quantum network. In the previous experiments, individual elements of a quantum network, such as the generation, storage and transmission of quantum entanglement have been demonstrated separately. Here we report an experiment to show the compatibility of these basic operations. Specifically, we generate photon-atom entanglement in a $6\times 5$ MAQM, convert the spin wave to time-bin photonic excitation after a controllable storage time, and then store and retrieve the p…
Chip-Integrated Broadband Multi-Photon Source for Wavelength-Multiplexed Quantum Networks
本研究通过芯片集成的宽带多光子源实现电信波段四光子纠缠，展示了高保真度和高效率的量子态生成，为密集波长复用量子网络提供了实用方案。
The implementation of quantum repeaters needed for long-distance quantum communication requires the generation of quantum entanglement distributed among the elementary links. These entanglements must be swapped among the quantum repeaters through Bell-state measurements. This study aims to improve the entanglement generation rate by frequency multiplexing the Bell-state measurements. As a preliminary step of the frequency-multiplexed Bell-state measurements, three frequency modes are mapped to a temporal mode by an atomic frequency comb prepared in $\mathrm{Pr^{3+}}$ ion-doped $\mathrm{Y_2SiO_…
Space-division multiplexed quantum key distribution exploiting multi-plane light conversion for few-mode fibers
研究利用多平面光转换实现少模光纤的空分复用量子密钥分发，通过单独单模光纤选择性激发模式，经MPLC分离到不同端口，演示了空间复用BBM92 QKD方案，给出复用链路量子误码率，为相关量子网络架构提供支持。
Multiplexed quantum memories and high-dimensional entanglement can improve the performance of quantum repeaters by promoting the entanglement generation rate and the quantum communication channel capacity. Here, we experimentally generate a high-dimensional entangled state between a photon and a collective spin wave excitation stored in the multiplexed atomic quantum memory. We verify the entanglement dimension by the quantum witness and the entanglement of formation. Then we use the high-dimensional entangled state to test the violation of the Bell-type inequality. Our work provides an effect…
Entanglement distribution over 150 km in wavelength division multiplexed channels for quantum cryptography
授予信息隐私权在我们的社会中至关重要，特别是在光纤通信网络中。量子密码学提供了一种独特的方法，可以在远程位置建立真正随机比特的相同字符串，其保密级别使用经典资源无法达到。然而，几个约束，如非优化的光子数统计和资源，探测器的噪声，和光损耗，目前限制了性能方面的可实现的密钥速率和距离。在这里，这些问题是解决使用的方法，结合了基本的和现成的技术资源。高质量的二分光子纠缠分布在150公里的光纤链路，利用波长解复用策略实现在最终用户的位置。它示出了如何符合率与所采用的电信信道的数量线性缩放，与值优于以前的实现几乎一个数量级。由于其潜在的可扩展性和与设备无关的策略的兼容性，该系统已经为真正的量子应用做好了准备，特别是基于纠缠的量子密码学。
Single and Double-click High-Rate Entanglement Generation Between Distant Ions Using Multiplexed Atomic Ensembles
本文研究了通过多路原子团簇实现远距离离子单击和双击高效率纠缠生成的方法，比较了单击和双击方案的相位稳定性要求和有限效率影响，提出了最优协议的选择依赖于相位稳定性和接口效率。
The development and wide application of quantum technologies highly depend on the capacity of the communication channels distributing entanglement. Space-division multiplexing (SDM) enhanced channel capacities in classical telecommunication and bears the potential to transfer the idea to quantum communication using current infrastructure. Here, we demonstrate an SDM of polarization-entangled photons over a 411m long 19-core multicore fiber distributing polarization-entangled photon pairs through up to 12 channels simultaneously. The quality of the multiplexed transfer is evidenced by high pola…
Two Photon Tripartite Entanglement Transfer via Time-Multiplexed Quantum Walks
该研究通过时间复用量子行走实现双光子三元纠缠转移，利用纠缠和不可分离性相互作用，将纠缠从偏振自由度转移到位置自由度。
Improvement of entanglement generation rate in frequency-multiplexed quantum repeaters using cavity-enhanced SPDC source
本文研究了基于cSPDC的频率复用量子中继器，通过推导频率复用光子的量子态表达式，计算了单光子干涉方案中纠缠生成的 heralding 概率和保真度，证明了在100模式复用下，25公里距离的 heralding 概率可提高至98%。
Entanglement swapping across a five-node relay in a multiplexed quantum-classical network
本研究首次在同一光纤上实现纠缠交换与经典通信共存，通过五节点中继和40公里光纤传输10-Gbps数据，为量子与经典网络融合部署提供路线图。
Feasible distribution of quantum entanglement over long distances remains a fundamental step towards quantum secure communication and quantum network implementations. Quantum repeater nodes based on quantum memories promise to overcome exponential signal decay inherent to optical implementations of quantum communication. While performance of current quantum memories hinders their practical application, multimode solutions with multiplexing can offer tremendous increase in entanglement distribution rates. We propose to use a wavevector-multiplexed atomic quantum memory (WV-MUX-QM) as a fundamen…
Heralded entanglement of on-demand spin-wave solid-state quantum memories for multiplexed quantum network links
本文结合窄带参量光子对源与稀土掺杂晶体固态量子存储器，实现空间分离自旋波存储器间的电信预示纠缠，支持按需读取、前馈相移和15模式时间复用。
Time-Multiplexed Measurements of Nonclassical Light at Telecom Wavelengths
我们报告的实验重建的统计特性的超快脉冲II型参量下转换源在电信波长的周期性极化KTP波导，几乎完美的光子数相关性。我们使用了基于光纤装置和一对雪崩光电二极管的光子数分辨时间复用检测器。通过采用密切相关的数据模式层析成像，我们以前所未有的精确度评估了非经典轻态的性质。
On-chip multiplexed multiple entanglement sources in a single silicon nanowire
片上硅（SOI）光子电路以其低损耗、小尺寸、兼容CMOS和电信通信技术等优点，成为最有前途的可扩展量子信息技术平台。多路复用纠缠源包括：基于1cm长单根硅纳米线的能量时间纠缠源、时间箱纠缠源和偏振纠缠源，所有这些源都兼容（100 GHz）密集波分复用（DWDM）系统。利用双光子干涉图、Bell不等式和量子态层析等方法对纠缠源的性质进行了表征。在超过5个通道对上产生多个缠结，具有约97%（100%）的高原始（净）活力。这些纠缠源的发射光谱亮度达到4.2 × 105 /（s·nm·mW）。比较了连续泵浦和脉冲泵浦下产生的光子对的质量。这些高质量的多路复用纠缠源使它们非常有希望用于未来的最小化量子通信和计算系统。
Entanglement Routing over Networks with Time Multiplexed Repeaters
针对全局链路状态导致的高延迟与长量子存储需求，论文提出两种仅用局部信息、结合多路径与时间复用中继器的纠缠路由协议，并分析了块长、成功率及存储相干时间对最优性能的影响。
The quantum interface (QI) that generates entanglement between photonic and spin-wave (atomic memory) qubits is a basic building block for quantum repeaters. Realizing ensemble-based repeaters in practice requires quantum memory providing long lifetime and multimode capacity. Significant progresses have been achieved on these separate goals. The remaining challenge is to combine long-lived and multimode memories into a single QI. Here, by establishing multimode, magnetic-field-insensitive and long-wavelength spin-wave storage in laser-cooled atoms that are placed inside a phase-passively-stabi…
Towards a fiber-optic temporally multiplexed single photon source
本研究通过对光通信波段连续波预报光子源进行时域复用，在全光纤结构中主动调谐光子延迟实现与外部时钟同步，添加时域校正级提升了单光子源品质因数，获得约1.8倍亮度提升及信噪比增强，为该波段集成非经典光子源奠定基础。
Multiplexed quantum repeaters based on single-photon interference with mild stabilization
本文提出一种基于单光子干涉的量子中继器方案，通过降低相位稳定难度并利用多模量子存储器和双光子源等可行技术，实现了比现有方案更高的端节点纠缠分发率，推动了多模量子中继器发展。
Wavelength-Multiplexed Quantum Networks with Ultrafast Frequency Combs
高度纠缠的量子网络簇态是量子计算\cite{Nielsen2006,Lloyd2012}最新方法的核心。然而，用于构建光量子网络的当前方法一次一个节点地\cite{Furusawa2008,Furusawa2009,Peng2012}这样做，这缺乏可扩展性。在这里，我们展示了\emph{single-step}制造的多模量子网络的参数下转换的飞秒频率梳。超快脉冲整形\cite{weiner2000}被用来表征梳状结构的光谱纠缠\cite{vanLoock2003}。10个光谱区域之间的511个可能的二分区中的每一个被示出为纠缠的;此外，本征模分解揭示了8个独立的量子信道\cite{Braunstein2005}（qumodes）被包含在梳内。这种纠缠通过利用频率纠缠来提高量子信道容量，将经典的波分复用（WDM）概念引入到量子域。量子频率梳易于寻址，相对于退相干是鲁棒的，并且是可扩展的，这使得它成为量子信息的独特工具。
Proof-of-principle demonstration of temporally multiplexed quantum repeater link based on atomic ensemble
本研究基于原子系综实现了时分复用量子中继链路的原理性验证，通过腔增强方案将自旋波按需读取效率提升至70%，链路制备速率较单模提升一个数量级，为实用化量子网络发展奠定基础。
A qubit memory is the building block for quantum information. Cavity-enhanced spin-wave-photon entanglement has been achieved by applying dual-control modes. However, owing to cross readouts between the modes, the qubit retrieval efficiency is about one quarter lower than that for a single spin-wave mode at all storage times. Here, we overcome cross readouts using a multiplexed ring cavity. The cavity is embedded with a polarization interferometer, and we create a write-out photonic qubit entangled with a magnetic-field-insensitive spin-wave qubit by applying a single-mode write-laser beam to …
Waveguide-array-based multiplexed photonic interface for atom array
本文提出了一种基于波导阵列的多路复用光子接口，用于实现大规模量子处理单元的网络化，通过Rydberg门实现原子与光子的高效纠缠生成。
Crosstalk-induced excess noise is experimentally characterized for continuous-variable quantum key distribution, spatially multiplexed with WDM PM-16QAM channels in a 19-core fiber. The measured noise-sources are used to estimate the secret key rates for different wavelength channels.
In a quantum network that successfully creates links, shared Bell states between neighboring repeater nodes, with probability $p$ in each time slot, and performs Bell State Measurements at nodes with success probability $q<1$, the end to end entanglement generation rate drops exponentially with the distance between consumers, despite multi-path routing. If repeaters can perform multi-qubit projective measurements in the GHZ basis that succeed with probability $q$, the rate does not change with distance in a certain $(p,q)$ region, but decays exponentially outside. This region where the distanc…
CMOS-compatible, multiplexed source of heralded photon pairs: towards integrated quantum combs
我们报告了一个集成的光子对源的基础上CMOS兼容的微波谐振器，产生多个，同时，和独立的光子对在不同波长的频率梳兼容光纤通信波分复用信道（200 GHz的信道分离）和线宽，是兼容的量子存储器（110 MHz）。它在自锁泵配置中运行，无需主动稳定，即使在非常低的功率水平下也非常稳定。
A solid-state temporally multiplexed quantum memory array at the single-photon level
本文实现了一个包含十个可单独控制存储单元的固态空间复用量子存储器阵列，结合时间复用技术，在单光子水平下将弱相干脉冲存储于多达250个时空模式中，平均信噪比为10(2)，系统串扰低，有望加速量子节点间的纠缠分发速率。
A Large-Scale Reconfigurable Multiplexed Quantum Photonic Network
本文提出一种可编程8x8维多端口电路，利用多模光纤实现两个局域多用户网络间纠缠的可重构复用路由与隐形传态，展示了大规模全球量子网络的潜力。
Channel-selective frequency up-conversion for frequency-multiplexed quantum network
该研究提出了一种基于二阶非线性光学的通道选择性频率上转换技术，用于提升频率复用量子网络中不同频率光子的交互效率和测量精度。
A Metropolitan-scale Multiplexed Quantum Repeater with Bell Nonlocality
本文提出一种基于时间测量的多端量子中继器协议，实现了14.5公里距离下固态量子记忆间的 heralded 非局域纠缠，并首次在城市级量子中继器中验证了贝尔非局域性。
High-quality photonic entanglement for wavelength-multiplexed quantum communication based on a silicon chip
报道了一种基于CMOS兼容硅光子环形腔四波混频的能量时间纠缠光子对源。经过适当的优化，在$\rm 500\,μW$泵浦功率下，该光源具有400对纠缠光子/s/MHz的高光谱亮度.此外，谐振器已经被设计成产生与标准电信密集波分复用器兼容的频率梳结构。我们证明了高纯度的能量-时间纠缠，即，没有光子噪声，在电信C波段中的各种信道对之间具有接近完美的原始噪声（$>$ ~98\%）。这样一个紧凑的源代表了一条通往更复杂的量子光子电路的道路，专用于量子通信系统。
Time-Multiplexed Distributed Quantum Sensing
本文通过时间域复用实现量子传感的灵敏度提升，突破传统线性限制，实现光子、空间模式和重复次数的Heisenberg标度。
Efficient heralding of O-band passively spatial-multiplexed photons for noise-tolerant quantum key distribution
当在承载C波段数据业务的光纤传输线上实现O波段量子密钥分发时，由自发拉曼散射或经典数据信道的不充分滤波引起的噪声光子可能导致量子误码率超过安全阈值。在这种情况下，可以使用光子预告方案来拒绝不相关的噪声光子，以便将量子比特错误率恢复到低水平。然而，除非使用具有足够高的预告速率和预告效率的预告光子源，否则安全密钥速率将受到影响。在这项工作中，我们展示了一个预示光子源，具有预示效率高达74.5%。典型的预告光子源的一个缺点是预告探测器的长死区时间导致预告速率的显著下降。为了解决这个问题，我们提出了一种在预告臂处的被动空间复用配置。在这种配置中使用两个预告探测器，我们获得了预告率提高37%，预告光子探测率相应提高16%。通过在10 km长的噪声光纤中传输O波段光子，观察了量子误码率与传输光子的噪声退化二阶关联函数之间的关系。我们还观察和讨论了后脉冲对缩短探测器死时间的影响。
All-photonic GKP-qubit repeater using analog-information-assisted multiplexed entanglement ranking
提出一种基于玻色GKP码的双向多路复用量子中继器架构，利用模拟信息辅助纠缠交换排序，无需大型簇态即可实现超1000公里高鲁棒性量子通信。
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