Quantum Science and Technology最新文献_第3页

Multi-mode global driving of trapped ions for quantum circuit synthesis 量子电路合成中捕获离子的多模全局驱动

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-06-25 DOI: 10.1088/2058-9565/ade560

Philip Richerme

引用次数: 0

Dynamical structure factor from weak measurements 弱测量的动力结构因子

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-06-24 DOI: 10.1088/2058-9565/ade335

E Altuntaş, R G Lena, S Flannigan, A J Daley and I B Spielman

{"title":"Dynamical structure factor from weak measurements","authors":"E Altuntaş, R G Lena, S Flannigan, A J Daley and I B Spielman","doi":"10.1088/2058-9565/ade335","DOIUrl":"https://doi.org/10.1088/2058-9565/ade335","url":null,"abstract":"Much of our knowledge of quantum systems is encapsulated in the expectation value of Hermitian operators, experimentally obtained by averaging projective measurements. However, dynamical properties are often described by products of operators evaluated at different times; such observables cannot be measured by individual projective measurements, which occur at a single time. For example, the dynamical structure factor (DSF) describes the propagation of density excitations, such as phonons, and is derived from the spatial density operator evaluated at different times. In equilibrium systems this can be obtained by first exciting the system at a specific wavevector and frequency, then measuring the response. Here, we describe an alternative approach using a pair of time-separated weak measurements, and analytically show that their cross-correlation function directly recovers the DSF, for all systems, even far from equilibrium. This general schema can be applied to obtain the cross-correlation function of any pair of weakly observable quantities. We provide numerical confirmation of this technique with a matrix product states simulation of the one-dimensional Bose–Hubbard model, weakly measured by phase contrast imaging. We explore the limits of the method and demonstrate its applicability to real experiments with limited imaging resolution.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"13 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144479076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Communication with quantum catalysts 与量子催化剂的通信

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-06-24 DOI: 10.1088/2058-9565/ade284

Yuqi Li, Junjing Xing, Dengke Qu, Lei Xiao, Zhaobing Fan, Zhu-Jun Zheng, Haitao Ma, Peng Xue, Kishor Bharti, Dax Enshan Koh and Yunlong Xiao

{"title":"Communication with quantum catalysts","authors":"Yuqi Li, Junjing Xing, Dengke Qu, Lei Xiao, Zhaobing Fan, Zhu-Jun Zheng, Haitao Ma, Peng Xue, Kishor Bharti, Dax Enshan Koh and Yunlong Xiao","doi":"10.1088/2058-9565/ade284","DOIUrl":"https://doi.org/10.1088/2058-9565/ade284","url":null,"abstract":"Communication is essential for advancing science and technology. Quantum communication, in particular, benefits from the use of catalysts. During the communication process, these catalysts enhance performance while remaining unchanged. Although chemical catalysts that undergo deactivation typically perform worse than those that remain unaffected, quantum catalysts, referred to as embezzling catalysts, can surprisingly outperform their non-deactivating counterparts despite experiencing slight alterations. In this work, we employ embezzling quantum catalysts to enhance the transmission of both quantum and classical information. By utilizing finite-dimensional embezzling catalysts, we guarantee a non-zero catalytic channel capacity for any quantum channel while keeping variations in the catalytic system arbitrarily small. Our protocol also improves long-distance entanglement distribution. Furthermore, we introduce catalytic superdense coding, demonstrating how embezzling catalysts can boost the transmission of classical information. Finally, we explore methods to reduce the dimensionality of catalysts, a step toward making quantum catalysis a practical reality.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"53 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144479066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Thirty years of quantum computing 三十年的量子计算

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-06-22 DOI: 10.1088/2058-9565/ade0e4

David P DiVincenzo

引用次数: 0

Classical shadows with improved median-of-means estimation 改进中位数估计的经典阴影

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-06-19 DOI: 10.1088/2058-9565/addffd

Winston Fu, Dax Enshan Koh, Siong Thye Goh and Jian Feng Kong

{"title":"Classical shadows with improved median-of-means estimation","authors":"Winston Fu, Dax Enshan Koh, Siong Thye Goh and Jian Feng Kong","doi":"10.1088/2058-9565/addffd","DOIUrl":"https://doi.org/10.1088/2058-9565/addffd","url":null,"abstract":"The classical shadows protocol, introduced by Huang et al (2020 Nat. Phys.16 1050), makes use of the median-of-means (MoM) estimator to efficiently estimate the expectation values of M observables with failure probability δ using only measurements. In their analysis, Huang et al used loose constants in their asymptotic performance bounds for simplicity. However, the specific values of these constants can significantly affect the number of shots used in practical implementations. To address this, we studied a modified MoM estimator proposed by Minsker (2023 Proc. 36th Conf. on Learning Theory (PMLR) 195 5925) that uses optimal constants and involves a U-statistic over the data set. For efficient estimation, we implemented two types of incomplete U-statistics estimators, the first based on random sampling and the second based on cyclically permuted sampling. We compared the performance of the original and modified estimators when used with the classical shadows protocol with single-qubit Clifford unitaries (Pauli measurements) for an Ising spin chain, and global Clifford unitaries (Clifford measurements) for the Greenberger–Horne–Zeilinger state. While the original estimator outperformed the modified estimators for Pauli measurements, the modified estimators showed improved performance over the original estimator for Clifford measurements. Our findings highlight the importance of tailoring estimators to specific measurement settings to optimize the performance of the classical shadows protocol in practical applications.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"44 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental demonstration of enhanced quantum tomography via quantum reservoir processing 利用量子库处理增强量子层析成像的实验演示

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-06-19 DOI: 10.1088/2058-9565/addffe

Tanjung Krisnanda, Pengtao Song, Adrian Copetudo, Clara Yun Fontaine, Tomasz Paterek, Timothy C H Liew and Yvonne Y Gao

{"title":"Experimental demonstration of enhanced quantum tomography via quantum reservoir processing","authors":"Tanjung Krisnanda, Pengtao Song, Adrian Copetudo, Clara Yun Fontaine, Tomasz Paterek, Timothy C H Liew and Yvonne Y Gao","doi":"10.1088/2058-9565/addffe","DOIUrl":"https://doi.org/10.1088/2058-9565/addffe","url":null,"abstract":"Quantum machine learning is a rapidly advancing discipline that leverages the features of quantum mechanics to enhance the performance of computational tasks. Quantum reservoir processing (QRP), which allows efficient optimization of a single output layer without precise control over the quantum system, stands out as one of the most versatile and practical quantum machine learning techniques. Here we experimentally demonstrate a QRP approach for continuous-variable state reconstruction on a bosonic circuit quantum electrodynamics platform. The scheme learns the true dynamical process through a minimum set of measurement outcomes of a known set of initial states. We show that the map learnt this way achieves high reconstruction fidelity for several test states, offering significantly enhanced performance over using a map calculated based on an idealized model of the system. This is due to a key feature of reservoir processing which accurately accounts for physical non-idealities such as decoherence, spurious dynamics, and systematic errors. Our results present a valuable tool for robust bosonic state and process reconstruction, concretely demonstrating the power of QRP in enhancing real-world applications.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"607 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Single photon coherent Ising machines for constrained optimization problems 约束优化问题的单光子相干伊辛机

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-06-19 DOI: 10.1088/2058-9565/addde5

Masahito Kumagai, Yoshitaka Inui, Edwin Ng, Satoshi Kako, Kazuhiko Komatsu, Hiroaki Kobayashi and Yoshihisa Yamamoto

{"title":"Single photon coherent Ising machines for constrained optimization problems","authors":"Masahito Kumagai, Yoshitaka Inui, Edwin Ng, Satoshi Kako, Kazuhiko Komatsu, Hiroaki Kobayashi and Yoshihisa Yamamoto","doi":"10.1088/2058-9565/addde5","DOIUrl":"https://doi.org/10.1088/2058-9565/addde5","url":null,"abstract":"A Coherent Ising machine (CIM) is an oscillator-network-based analog computing system to circumvent the bottleneck in von Neumann digital computing architectures. The CIM consists of a network of degenerate optical parametric oscillators (DOPOs) and is designed to find a ground state or perform Boltzmann sampling for all degenerate ground states and low-energy excited states in combinatorial optimization problems. A nonlinear measurement feedback scheme, called chaotic amplitude control (CAC), has recently been proposed to correct pulse amplitude inhomogeneity and thereby faithfully map the Ising Hamiltonian to the loss landscape of the DOPO network. However, the quantum limit of the CIM-CAC performance is not fully explored yet. This work clarifies how the quantum noise squeezing and the measurement-induced state shift in repeated indirect quantum measurements improve the system performance. From the numerical simulation on the Ising model with the Zeeman terms, obtained from combinatorial clustering problems formulated as constrained optimization problems, it is revealed that the CIM-CAC operating in a single photon per pulse regime dramatically outperforms the standard CIM-CAC with a large photon number per pulse. This is because the standard CIM-CAC is often trapped in a periodic trajectory and cannot escape from there. On the other hand, the significant improvement is brought by the noise-induced amplitude jump in the single photon CIM-CAC.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"15 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Error-tolerant witnessing of divergences in classical and quantum statistical complexity 经典和量子统计复杂性发散的容错见证

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-06-18 DOI: 10.1088/2058-9565/addfff

Farzad Ghafari, Mile Gu, Joseph Ho, Jayne Thompson, Whei Yeap Suen, Howard M Wiseman and Geoff J Pryde

引用次数: 0

Quantum networks using rare-earth ions 使用稀土离子的量子网络

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-06-15 DOI: 10.1088/2058-9565/addd93

Wolfgang Tittel, Mikael Afzelius, Adam Kinos, Lars Rippe and Andreas Walther

引用次数: 0

Improved amplitude amplification strategies for the quantum simulation of classical transport problems 经典输运问题量子模拟的改进振幅放大策略

IF 6.7 2区物理与天体物理

Quantum Science and Technology Pub Date : 2025-06-10 DOI: 10.1088/2058-9565/addeea

Alessandro Andrea Zecchi, Claudio Sanavio, Simona Perotto and Sauro Succi

{"title":"Improved amplitude amplification strategies for the quantum simulation of classical transport problems","authors":"Alessandro Andrea Zecchi, Claudio Sanavio, Simona Perotto and Sauro Succi","doi":"10.1088/2058-9565/addeea","DOIUrl":"https://doi.org/10.1088/2058-9565/addeea","url":null,"abstract":"The quantum simulation of classical fluids often involves the use of probabilistic algorithms that encode the result of the dynamics in the form of the amplitude of the selected quantum state. In most cases, however, the amplitude probability is too low to allow an efficient use of these algorithms, thereby hindering the practical viability of the quantum simulation. The oblivious amplitude amplification (OAA) algorithm is often presented as a solution to this problem, but to no avail for most classical problems, since its applicability is limited to unitary dynamics. In this paper, we show analytically that OAA when applied to non-unitary dynamics leads to a distortion of the quantum state and to an accompanying error in the quantum update. We provide an analytical upper bound of such error as a function of the degree of non-unitarity of the dynamics and we test it against a quantum simulation of an advection-diffusion-reaction equation, a transport problem of major relevance in science and engineering. Finally, we also propose an amplification strategy that helps mitigate the distortion error, while still securing an enhanced success probability.","PeriodicalId":20821,"journal":{"name":"Quantum Science and Technology","volume":"8 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144260452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0