Quantum computational advantage using photons Zhong, Han-Sen; Wang, Hui; Deng, Yu-Hao ...
Science (American Association for the Advancement of Science),
12/2020, Volume:
370, Issue:
6523
Journal Article
Peer reviewed
Open access
Quantum computers promise to perform certain tasks that are believed to be intractable to classical computers. Boson sampling is such a task and is considered a strong candidate to demonstrate the ...quantum computational advantage. We performed Gaussian boson sampling by sending 50 indistinguishable single-mode squeezed states into a 100-mode ultralow-loss interferometer with full connectivity and random matrix-the whole optical setup is phase-locked-and sampling the output using 100 high-efficiency single-photon detectors. The obtained samples were validated against plausible hypotheses exploiting thermal states, distinguishable photons, and uniform distribution. The photonic quantum computer,
, generates up to 76 output photon clicks, which yields an output state-space dimension of 10
and a sampling rate that is faster than using the state-of-the-art simulation strategy and supercomputers by a factor of ~10
.
We report phase-programmable Gaussian boson sampling (GBS) which produces up to 113 photon detection events out of a 144-mode photonic circuit. A new high-brightness and scalable quantum light source ...is developed, exploring the idea of stimulated emission of squeezed photons, which has simultaneously near-unity purity and efficiency. This GBS is programmable by tuning the phase of the input squeezed states. The obtained samples are efficiently validated by inferring from computationally friendly subsystems, which rules out hypotheses including distinguishable photons and thermal states. We show that our GBS experiment passes a nonclassicality test based on inequality constraints, and we reveal nontrivial genuine high-order correlations in the GBS samples, which are evidence of robustness against possible classical simulation schemes. This photonic quantum computer, Jiuzhang 2.0, yields a Hilbert space dimension up to ∼ 1043, and a sampling rate ∼ 1024 faster than using brute-force simulation on classical supercomputers.
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The interactions between precipitation, runoff and sedimentation could reveal information about the processes of runoff and sediment production and the environmental evolution mechanisms of basins. ...Based on the hydrometeorological data collected over a long-term time series (1955–2012) which has been divided into five periods (P1 (1956–1969), P2 (1970–1979), P3 (1980–1989), P4 (1990–1999) and P5 (2000−2012)), changes and implications of the relationships between precipitation, runoff and sediment load (precipitation-runoff-sediment relationships) were studied in the Wuding River basin, China. Conclusions are as follows. (1) There is no obvious change occurs on the distribution of annual precipitation during 1955 to 2012. However, the annual runoff and sediment load are significantly decreased by 51.9% and 86.4%, respectively, from P1 to P5. (2) Under the same precipitation conditions, the runoff and sediment present overall decreasing trends. Decrease in the runoff was greater than that in the sediment load. The incoming sediment coefficient (ISC) reduced by 69.2%, indicating that the sediment transport ability per unit runoff was weakened. The significant reduction of ISC along with the decrease of the runoff amount caused the sediment brought into the Yellow River (STWY) decreased from P1 to P5. (3) Soil conservation measures played a critical role for the changes in precipitation-runoff-sediment relationships. Due to the rapid increases in the available storage of check dams in P2 and P5 and the areas of forest and grassland in P2, relationships among the precipitation, runoff and sediment has drastically changed. Decrease of the effects on sediment interception in check dams caused the sediment increased from P3 to P4. (4) Decreases of runoff and sediment load, and changes in their relationships would continue with the sustainable management of slopes and gullies. The potentially detrimental changes in the storage of check dams and those in runoff and sediment influenced by extreme weather conditions should be monitored and managed.
•The annual runoff and sediment load have shown significant decreases (P < 0.05).•Human activities are the main driving factor of the changes in these relationships.•The decreasing effects of intercepting sediment led to the sediment increase in P4.•The STWY decreased because of the decreases in the ISC and runoff amount.•Changes in runoff and sediment under extreme weather should be considered.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Two measurement attributes related to clustering in LSGDM problems are explored.•Trust relationship and opinion similarity are both important in LSGDM scenarios.•Trust-similarity analysis (TSA) is ...developed to implement clustering operations.•A TSA-based clustering method is proposed for LSGDM events under social network.•A TSA plot is built to visualize the clustering processes.
Large-scale group decision-making (LSGDM) under a social network context has attracted much attention in the field of decision science. The clustering of individual opinions and the handling of trust relationships are the main research topics. Opinion similarity and trust relationship are considered to be two important measurement attributes for implementing clustering. Traditional clustering methods often use a single attribute to divide the original group without requiring a combination of the above two attributes. However, these two attributes play different roles in the clustering process, insofar as opinion similarity is used to measure the level of difference among individual opinions, whereas the trust relationship represents the trustworthiness of decision makers. This paper develops a trust-similarity analysis (TSA)-based clustering method to manage the clustering operation in LSGDM events under a social network context. First, the trust-similarity matrix is established to collectively describe the decision information. Second, all measurement attribute values are mapped to a trust-similarity plot from which the joint threshold can be calculated. Finally, a TSA-based clustering method is proposed that considers the attributes of opinion similarity and trust relationship and that allocates their importance to achieve specific clustering objectives. The numerical experiment and comparative analysis reveal the feasibility and advantages of the proposed method.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
QUasi-Affine TRansformation Evolutionary algorithm (QUATRE) is a new optimization algorithm based on population for complex multiple real parameter optimization problems in real world. In this paper, ...a novel multi-group multi-choice communication strategy algorithm for QUasi-Affine TRansformation Evolutionary (MM-QUATRE) algorithm is proposed to solve the disadvantage that the original QUATRE is always easily to fall into local optimization in the strategy of updating bad nodes with multiple groups and multiple choices. We compared it with other intelligent algorithms, the most advanced PSO variant, parallel PSO (P-PSO) variant, native QUATRE and parallel QUATRE (P-PSO) under CEC2013 large-scale optimization test suite. Thus, the performance of MM-QUATRE was verified. The conclusion that the MM-QUATRE algorithm is superior to other intelligent algorithms is proved by the experimental results. In addition, the application results of MM-QUATRE algorithm (MM-QUATRE-RSSI) based on RSSI in WSN node localization were analyzed and studied. The results appear that this method has higher localization accuracy than other similar algorithms.
Wound healing is a dynamic and highly regulated process that can be separated into three overlapping and interdependent phases: inflammation, proliferation, and remodelling. This review focuses on ...the inflammation stage, as it is the key stage of wound healing and plays a vital role in the local immune response and determines the progression of wound healing. Inflammatory cells, the main effector cells of the inflammatory response, have been widely studied, but little attention has been paid to the immunomodulatory effects of wound healing in non-inflammatory cells and the extracellular matrix. In this review, we attempt to deepen our understanding of the wound-healing microenvironment in the inflammatory stage by focusing on the interactions between cells and the extracellular matrix, as well as their role in regulating the immune response during the inflammatory stage. We hope our findings will provide new ideas for promoting tissue regeneration through immune regulation.
Periodically driven systems have displayed a variety of fascinating phenomena without analogies in static systems, which enrich the classification of quantum phases of matter and stimulate a wide ...range of research interests. Here, we employ discrete-time quantum walks to investigate a nontrivial topological effect unique to a two-dimensional periodically driven system: chiral edge states can exist at the interface of Floquet insulators whose Chern numbers vanish. Thanks to a resource-saving and flexible fiber-loop architecture, we realize inhomogeneous two-dimensional quantum walks up to 25 steps, over an effective 51×51 lattice with tunable local parameters. Spin-polarized chiral edge states are observed at the boundary of two distinct quantum walk domains. Our results contribute to establishing a well-controlled platform for exploring nontrivial topological phases.
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Group decision-making (GDM) in large-group social network environment (LGSNE) has attracted considerable attention in the field of decision science. Social relationships exist among decision-makers, ...and individual decisions are often influenced by others they are connected with. Opinions among large-scale decision-makers can easily be controversial and conflicting. Reaching consensus is necessary, but it requires the adjustment of some individual opinions. Due to differences in self-interest and perception, some decision-makers are noncooperative with regard to adjusting their opinions to promote consensus. This may delay consensus convergence and ultimately affect decision quality. This study proposes a two-dimensional consensus convergence model considering noncooperative behaviors. We first describe the characteristics of GDM problems in LGSNE. Two measurement attributes – trust relationship and opinion similarity – are identified as important factors throughout the decision-making process. Then, we propose a hierarchical clustering method based on the trust–similarity measure. A weight-determining method for clusters is presented that considers the internal and external features of a cluster. Based on these, a two-dimensional consensus convergence process is designed to reduce opinion differences and manage noncooperative behaviors. Finally, a numerical experiment is used to illustrate the feasibility and efficacy of the proposed model, and comparative analysis reveals its features and advantages.
•The characteristics and components of GDM problems in LGSNE are analyzed.•Opinion similarity and trust relationship are important for GDM events in LGSNE.•A trust–similarity measure-based hierarchical clustering method is presented.•A two-dimensional consensus convergence model is developed.•A weight-determining method for clusters considering multiple factors is proposed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Cancer-associated fibroblasts (CAFs) are the predominant components of the tumor microenvironment (TME) and influence cancer hallmarks, but without systematic investigation on their ubiquitous ...characteristics across different cancer types. Here, we perform pan-cancer analysis on 226 samples across 10 solid cancer types to profile the TME at single-cell resolution, illustrating the commonalities/plasticity of heterogenous CAFs. Activation trajectory of the major CAF types is divided into three states, exhibiting distinct interactions with other cell components, and relating to prognosis of immunotherapy. Moreover, minor CAF components represent the alternative origin from other TME components (e.g., endothelia and macrophages). Particularly, the ubiquitous presentation of endothelial-to-mesenchymal transition CAF, which may interact with proximal SPP1
tumor-associated macrophages, is implicated in endothelial-to-mesenchymal transition and survival stratifications. Our study comprehensively profiles the shared characteristics and dynamics of CAFs, and highlight their heterogeneity and plasticity across different cancer types. Browser of integrated pan-cancer single-cell information is available at https://gist-fgl.github.io/sc-caf-atlas/ .
RFID can automatically read the information stored on the tag. When multiple tags send data to the reader and writer at the same time, multiple tag collision will occur, resulting in the reader and ...writer being unable to successfully identify the tag. To solve this problem, an RFID multitag identification method based on decision tree is proposed. The Manchester code is used to represent different level states of voltage. The reader extracts the collision bits in the tag ID by using the Manchester code, and these collision bits form the new tag ID. In the process of decision tree search, the “XOR” command operation is added, and the query prefix is selectively sent to the tag to mark all collision bits. The process will continue until one tag is identified; then, reset the remaining unrecognized tags and continue to participate in a new round of identification. The simulation results show that the RFID multitag identification method based on decision tree can reduce the time complexity and communication overhead and improve the throughput, so it has high search efficiency.
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