We experimentally engineer a high-spectral-purity single-photon source using a single-interferometer-coupled silicon microring. By the reconfiguration of the interferometer, different coupling conditions can be obtain...
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We experimentally engineer a high-spectral-purity single-photon source using a single-interferometer-coupled silicon microring. By the reconfiguration of the interferometer, different coupling conditions can be obtained, corresponding to different quality factors for the pump and signal/idler. The ratio between the quality factor of the pump and signal/idler ranges from 0.29 to 2.57. By constructing the signal–idler joint spectral intensity, we intuitively demonstrate the spectral correlation of the signal and idler. As the ratio between the quality factor of the pump and signal/idler increases, the spectral correlation of the signal and idler decreases, i.e., the spectral purity of the signal/idler photons increases. Furthermore,time-integrated second-order correlation of the signal photons is measured, giving a value up to 94.95 ± 3.46%. Such high-spectral-purity photons will improve the visibility of quantum interference and facilitate the development of on-chip quantum information processing.
Smart contracts are widely used on the blockchain to implement complex transactions,such as decentralized applications on *** vulnerability detection of large-scale smart contracts is critical,as attacks on smart cont...
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Smart contracts are widely used on the blockchain to implement complex transactions,such as decentralized applications on *** vulnerability detection of large-scale smart contracts is critical,as attacks on smart contracts often cause huge economic *** it is difficult to repair and update smart contracts,it is necessary to find the vulnerabilities before they are ***,code analysis,which requires traversal paths,and learning methods,which require many features to be trained,are too time-consuming to detect large-scale on-chain ***-based methods will obtain detection models from a feature space compared to code analysis methods such as symbol *** the existing features lack the interpretability of the detection results and training model,even worse,the large-scale feature space also affects the efficiency of *** paper focuses on improving the detection efficiency by reducing the dimension of the features,combined with expert *** this paper,a feature extraction model Block-gram is proposed to form low-dimensional knowledge-based features from ***,the metadata is separated and the runtime code is converted into a sequence of opcodes,which are divided into segments based on some instructions(jumps,etc.).Then,scalable Block-gram features,including 4-dimensional block features and 8-dimensional attribute features,are mined for the learning-based model ***,feature contributions are calculated from SHAP values to measure the relationship between our features and the results of the detection *** addition,six types of vulnerability labels are made on a dataset containing 33,885 contracts,and these knowledge-based features are evaluated using seven state-of-the-art learning algorithms,which show that the average detection latency speeds up 25×to 650×,compared with the features extracted by N-gram,and also can enhance the interpretability of the detection model.
Maximal multi-photon entangled states,known as NOON states,play an essential role in quantum *** the number of photons growing,NOON states are becoming increasingly powerful and advantageous for obtaining supersensiti...
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Maximal multi-photon entangled states,known as NOON states,play an essential role in quantum *** the number of photons growing,NOON states are becoming increasingly powerful and advantageous for obtaining supersensitive and super-resolved *** this paper,we propose a universal scheme for generating three-and four-photon path-entangled NOON states on a reconfigurable photonic chip via photons subtracted from pairs and detected by heralding *** method is postselection free,enabling phase supersensitive measurements and sensing at the Heisenberg *** NOON-state generator allows for integration of quantum light sources as well as practical and portable precision phase-related measurements.
Optical isolators,the photonic analogs of electronic diodes,are essential for ensuring the unidirectional flow of light in optical systems,thereby mitigating the destabilizing effects of back ***-film lithium niobate(...
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Optical isolators,the photonic analogs of electronic diodes,are essential for ensuring the unidirectional flow of light in optical systems,thereby mitigating the destabilizing effects of back ***-film lithium niobate(TFLN),hailed as“the silicon of photonics,”has emerged as a pivotal material in the realm of chip-scale nonlinear optics,propelling the demand for compact optical *** report a breakthrough in the development of a fully passive,integrated optical isolator on the TFLN platform,leveraging the Kerr effect to achieve an impressive 10.3 dB of isolation with a minimal insertion loss of 1.87 *** theoretical simulations have demonstrated that our design,when applied to a microring resonator with a Q factor of 5×10^(6),can achieve 20 dB of isolation with an input power of merely 8 *** advancement underscores the immense potential of lithium niobate-based Kerr-effect isolators in propelling the integration and application of high-performance on-chip lasers,heralding a new era in integrated photonics.
In various network monitoring tasks, the detection of superspreaders has become increasingly crucial. However, latest superspreader detection algorithms and data structures assume the target switch with a single pipel...
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1 Introduction Artificial neural networks(ANNs,also NNs)have recently emerged as leading candidate models for deep learning,popularly used in various areas[1–3].Behind the enormous success,ANNs are generally with com...
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1 Introduction Artificial neural networks(ANNs,also NNs)have recently emerged as leading candidate models for deep learning,popularly used in various areas[1–3].Behind the enormous success,ANNs are generally with complicated structures,there being an intricate data flow through multiple linear or nonlinear components between the input layer and the output ***,it is pressing to evaluate how much a specific component contributes to the final output,termed the Credit Assignment Problem(CAP)[4]in this paper.
Place recognition is a crucial component in the realm of simultaneous localization and mapping (SLAM) and autonomous driving. It can also enhance the performance of loop closure detection and global localization. LiDA...
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Link Prediction(LP) is a fundamental problem in graph machine learning that aims to predict the existence of links between nodes. Most current research on LP adopts Graph Neural Networks (GNNs) to learn the representa...
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The passive noise-shaping successive approximation register(NS-SAR) analog-to-digital converter(ADC) demonstrates highperformance in resolution improvement, power reduction, and process scaling, while its charge-shar...
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The passive noise-shaping successive approximation register(NS-SAR) analog-to-digital converter(ADC) demonstrates highperformance in resolution improvement, power reduction, and process scaling, while its charge-sharing loss and limited bandwidth weaken the noise-shaping effect. This paper presents a first-order NSSAR ADC based on error-feedback(EF) structure to realize high-efficiency noise shaping. It employs a lossless EF path by using a set of ping-pong switching capacitors with passive signal-residue summation technique. The proposed first-order EF NS-SAR prototype can be promoted to multi-order structure with the minor modification. Verified by simulation in 65-nm CMOS process, the proposed 9-bit NS-SAR ADC consumes 183.66 μW when operating at 20 MS/s with the supply voltage of 1.2 V. At the oversampling ratio of 16, it achieves a peak signal-tonoise-and-distortion ratio of 81 d B, yielding Schreier figure of merit of 176.32 d B.
Person re-identification is a challenging problem in computer vision, aiming to accurately match and recognize the same individual across different viewpoints and cameras. Due to significant variations in appearance u...
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