npj Quantum Information最新文献_第4页

Unveiling quantum steering by quantum-classical uncertainty complementarity 量子经典不确定性互补性揭示量子导向

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-05-08 DOI: 10.1038/s41534-025-01017-w

Kuan-Yi Lee, Jhen-Dong Lin, Karel Lemr, Antonín Černoch, Adam Miranowicz, Franco Nori, Huan-Yu Ku, Yueh-Nan Chen

{"title":"Unveiling quantum steering by quantum-classical uncertainty complementarity","authors":"Kuan-Yi Lee, Jhen-Dong Lin, Karel Lemr, Antonín Černoch, Adam Miranowicz, Franco Nori, Huan-Yu Ku, Yueh-Nan Chen","doi":"10.1038/s41534-025-01017-w","DOIUrl":"https://doi.org/10.1038/s41534-025-01017-w","url":null,"abstract":"One of the remarkable aspects of quantum steering is its ability to violate local uncertainty complementarity relations. In this vein of study, various steering witnesses have been developed. Here, we introduce a novel complementarity relation between the system’s quantum and classical uncertainties corresponding to the distillable coherence and the von Neumann entropy, respectively. We show that the proposed complementarity relation is tighter than the entropic uncertainty relation (EUR). Leveraging this result, we propose a steering witness that is more efficient than the EUR. From the operational perspective, the steering witness quantifies the amount of extra distillable coherence facilitated by quantum steerability. Notably, the proposed steering witness serves as a full entanglement measure for pure bipartite states–an ability that the EUR lacks. We also experimentally validate such a property through a photonic system. Furthermore, a deeper connection to the uncertainty principle is revealed by showcasing the steering-induced distillable coherence can quantify measurement incompatibility and quantum steerability under genuine incoherent operations. Our work establishes a clear quantitative and operational link between coherence and steering, which are vital resources of quantum technologies, and underscores our efforts in bridging the uncertainty principle with quantum coherence.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"7 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143920381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Digital reconstruction of squeezed light for quantum information processing 量子信息处理中压缩光的数字重构

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-05-03 DOI: 10.1038/s41534-025-01018-9

Huy Q. Nguyen, Ivan Derkach, Adnan A. E. Hajomer, Hou-Man Chin, Akash nag Oruganti, Ulrik L. Andersen, Vladyslav Usenko, Tobias Gehring

{"title":"Digital reconstruction of squeezed light for quantum information processing","authors":"Huy Q. Nguyen, Ivan Derkach, Adnan A. E. Hajomer, Hou-Man Chin, Akash nag Oruganti, Ulrik L. Andersen, Vladyslav Usenko, Tobias Gehring","doi":"10.1038/s41534-025-01018-9","DOIUrl":"https://doi.org/10.1038/s41534-025-01018-9","url":null,"abstract":"Squeezed light plays a vital role in quantum information processing. However, its highly sensitive nature presents significant practical challenges, particularly in remote detection, which traditionally requires complex systems such as active phase locking, clock synchronization, and polarization control. Here, we propose and demonstrate an asynchronous detection method for squeezed light eliminating the need for these complex systems. By employing radio-frequency heterodyne detection with a locally generated local oscillator and applying a series of digital unitary transformations, we successfully reconstruct squeezed states of light. We validate our approach in two key applications: the distribution of squeezed light over a 10 km fiber channel, and passive continuous-variables quantum key distribution based on squeezed vacuum states between two labs connected via deployed fiber. This demonstrates a practical digital reconstruction method for squeezed light, opening new avenues for practical distributed quantum sensing networks and high-performance, long-distance quantum communication using squeezed states.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"15 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143901380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Variational quantum algorithm for enhanced continuous variable optical phase sensing 增强连续可变光学相位传感的变分量子算法

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-05-02 DOI: 10.1038/s41534-024-00947-1

Jens A. H. Nielsen, Mateusz J. Kicinski, Tummas N. Arge, Kannan Vijayadharan, Jonathan Foldager, Johannes Borregaard, Johannes Jakob Meyer, Jonas S. Neergaard-Nielsen, Tobias Gehring, Ulrik L. Andersen

{"title":"Variational quantum algorithm for enhanced continuous variable optical phase sensing","authors":"Jens A. H. Nielsen, Mateusz J. Kicinski, Tummas N. Arge, Kannan Vijayadharan, Jonathan Foldager, Johannes Borregaard, Johannes Jakob Meyer, Jonas S. Neergaard-Nielsen, Tobias Gehring, Ulrik L. Andersen","doi":"10.1038/s41534-024-00947-1","DOIUrl":"https://doi.org/10.1038/s41534-024-00947-1","url":null,"abstract":"Variational quantum algorithms (VQAs) are hybrid quantum-classical approaches used for tackling a wide range of problems on noisy intermediate-scale quantum (NISQ) devices. Testing these algorithms on relevant hardware is crucial to investigate the effect of noise and imperfections and to assess their practical value. Here, we implement a variational algorithm designed for optimized parameter estimation on a continuous variable platform based on squeezed light, a key component for high-precision optical phase estimation. We investigate the ability of the algorithm to identify the optimal metrology process, including the optimization of the probe state and measurement strategy for small-angle optical phase sensing. Two different optimization strategies are employed, the first being a gradient descent optimizer using Gaussian parameter shift rules to estimate the gradient of the cost function directly from the measurements. The second strategy involves a gradient-free Bayesian optimizer, fine-tuning the system using the same cost function and trained on the data acquired through the gradient-dependent algorithm. We find that both algorithms can steer the experiment towards the optimal metrology process. However, they find minima not predicted by our theoretical model, demonstrating the strength of variational algorithms in modelling complex noise environments, a non-trivial task.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"111 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143898085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Entanglement of photonic modes from a continuously driven two-level system 连续驱动双能级系统中光子模式的纠缠

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-04-28 DOI: 10.1038/s41534-025-00995-1

Jiaying Yang, Ingrid Strandberg, Alejandro Vivas-Viaña, Akshay Gaikwad, Claudia Castillo-Moreno, Anton Frisk Kockum, Muhammad Asad Ullah, Carlos Sánchez Muñoz, Axel Martin Eriksson, Simone Gasparinetti

{"title":"Entanglement of photonic modes from a continuously driven two-level system","authors":"Jiaying Yang, Ingrid Strandberg, Alejandro Vivas-Viaña, Akshay Gaikwad, Claudia Castillo-Moreno, Anton Frisk Kockum, Muhammad Asad Ullah, Carlos Sánchez Muñoz, Axel Martin Eriksson, Simone Gasparinetti","doi":"10.1038/s41534-025-00995-1","DOIUrl":"https://doi.org/10.1038/s41534-025-00995-1","url":null,"abstract":"The ability to generate entangled states of light is a key primitive for quantum communication and distributed quantum computation. Continuously driven sources, including those based on spontaneous parametric downconversion, are usually probabilistic, whereas deterministic sources require accurate timing of the control fields. Here, we experimentally generate entangled photonic modes by continuously exciting a quantum emitter - a superconducting qubit - with a coherent drive, taking advantage of mode matching in the time and frequency domain. Using joint quantum state tomography and logarithmic negativity, we show that entanglement is generated between modes extracted from the two sidebands of the resonance fluorescence spectrum. Because the entangled photonic modes are perfectly orthogonal, they can be transferred into distinct quantum memories. Our approach can be utilized to distribute entanglement at a high rate in various physical platforms, with applications in waveguide quantum electrodynamics, distributed quantum computing, and quantum networks.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"41 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143880829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Steering nonlocality in high-speed telecommunication system without detection loophole 无检测漏洞的高速通信系统转向非定域性研究

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-04-24 DOI: 10.1038/s41534-025-01021-0

Qiang Zeng, Huihong Yuan, Haoyang Wang, Lai Zhou, Zhiliang Yuan

{"title":"Steering nonlocality in high-speed telecommunication system without detection loophole","authors":"Qiang Zeng, Huihong Yuan, Haoyang Wang, Lai Zhou, Zhiliang Yuan","doi":"10.1038/s41534-025-01021-0","DOIUrl":"https://doi.org/10.1038/s41534-025-01021-0","url":null,"abstract":"Nonlocal correlation represents the key feature of quantum mechanics, and is an exploitable resource in quantum information processing. However, the loophole issues and the associated applicability compromises hamper the practical applications. We report the first time-bin entangled detection-loophole-free steering nonlocality demonstration in a fully chip-fiber telecommunication system, with an ultra-fast measurement switching rate (1.25 GHz). In this endeavor, we propose the phase-encoding measurement scheme to adapt the system to time-bin degree of freedom, and design and fabricate a low-loss silicon chip for efficient entanglement generation. An asymmetric configuration is introduced to mimic the active measurement implementation at the steering party thus bypassing the phase modulation loss. Consequently, we build a fiber-optic setup that can overcome the detection efficiency required by conclusive quantum steering with multiple actively switched measurement settings. Our setup presents an immediate platform for exploring applications based on steering nonlocality, especially for quantum communication.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"259 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143872892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Long optical and electron spin coherence times for erbium ions in silicon 硅中铒离子的长光学和电子自旋相干时间

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-04-18 DOI: 10.1038/s41534-025-01008-x

Ian R. Berkman, Alexey Lyasota, Gabriele G. de Boo, John G. Bartholomew, Shao Qi Lim, Brett C. Johnson, Jeffrey C. McCallum, Bin-Bin Xu, Shouyi Xie, Nikolay V. Abrosimov, Hans-Joachim Pohl, Rose L. Ahlefeldt, Matthew J. Sellars, Chunming Yin, Sven Rogge

{"title":"Long optical and electron spin coherence times for erbium ions in silicon","authors":"Ian R. Berkman, Alexey Lyasota, Gabriele G. de Boo, John G. Bartholomew, Shao Qi Lim, Brett C. Johnson, Jeffrey C. McCallum, Bin-Bin Xu, Shouyi Xie, Nikolay V. Abrosimov, Hans-Joachim Pohl, Rose L. Ahlefeldt, Matthew J. Sellars, Chunming Yin, Sven Rogge","doi":"10.1038/s41534-025-01008-x","DOIUrl":"https://doi.org/10.1038/s41534-025-01008-x","url":null,"abstract":"Spins in silicon that are accessible via a telecom-compatible optical transition are a versatile platform for quantum information processing that can leverage the well-established silicon nanofabrication industry. Key to these applications are long coherence times on the optical and spin transitions to provide a robust system for interfacing photonic and spin qubits. Here, we report telecom-compatible Er3+ sites with long optical and electron spin coherence times, measured within a nuclear spin-free silicon crystal (<0.01 % 29Si) using optical detection. We investigate two sites and find 0.1 GHz optical inhomogeneous linewidths and homogeneous linewidths below 70 kHz for both sites. We measure the electron spin coherence time of both sites using optically detected magnetic resonance and observe Hahn echo decay constants of 0.8 ms and 1.2 ms at ~ 11 mT. These optical and spin properties of Er3+:Si are an important milestone towards using optically accessible spins in silicon for a broad range of quantum information processing applications.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"49 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143849610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Unified framework for matchgate classical shadows 统一框架的匹配门经典阴影

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-04-16 DOI: 10.1038/s41534-025-01015-y

Valentin Heyraud, Héloise Chomet, Jules Tilly

{"title":"Unified framework for matchgate classical shadows","authors":"Valentin Heyraud, Héloise Chomet, Jules Tilly","doi":"10.1038/s41534-025-01015-y","DOIUrl":"https://doi.org/10.1038/s41534-025-01015-y","url":null,"abstract":"Estimating quantum fermionic properties is a computationally difficult yet crucial task for the study of electronic systems. Recent developments have begun to address this challenge by introducing classical shadows protocols relying on sampling of Fermionic Gaussian Unitaries (FGUs): a class of transformations in fermionic space which can be conveniently mapped to matchgates circuits. The different protocols proposed in the literature use different sub-ensembles of the orthogonal group O(2n) to which FGUs can be associated. We propose an approach that unifies these different protocols, proving their equivalence, and deriving from it an optimal sampling scheme. We begin by demonstrating that the first three moments of the FGU ensemble associated with SO(2n) and of its intersection with the Clifford group are equal, generalizing a result known for O(2n) and addressing a question raised in previous works. Building on this proof, we establish the equivalence between the shadows protocols resulting from FGU ensembles analyzed in the literature. Finally, from our results, we propose a sampling scheme for a small sub-ensemble of matchgates circuits that is optimal in terms of number of gates and that inherits the performances guarantees of the previous ensembles.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"26 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143836729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Universal term of entanglement entropy in the π-flux Hubbard model π-通量Hubbard模型中纠缠熵的通用项

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-04-15 DOI: 10.1038/s41534-025-01010-3

Yuan Da Liao

引用次数: 0

Dephasing and error dynamics affecting a singlet-triplet qubit during coherent spin shuttling 相干自旋穿梭过程中影响单重态-三重态量子比特的失相和误差动力学

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-04-12 DOI: 10.1038/s41534-025-00996-0

Natalie D. Foster, Jacob D. Henshaw, Martin Rudolph, Dwight R. Luhman, Ryan M. Jock

{"title":"Dephasing and error dynamics affecting a singlet-triplet qubit during coherent spin shuttling","authors":"Natalie D. Foster, Jacob D. Henshaw, Martin Rudolph, Dwight R. Luhman, Ryan M. Jock","doi":"10.1038/s41534-025-00996-0","DOIUrl":"https://doi.org/10.1038/s41534-025-00996-0","url":null,"abstract":"Quantum information transport over micron to millimeter scale distances is critical for the operation of practical quantum processors based on spin qubits. One method of achieving a long-range interaction is by coherent electron spin shuttling through an array of silicon quantum dots. In order to execute many shuttling operations with high fidelity, it is essential to understand the dynamics of qubit dephasing and relaxation during the shuttling process in order to mitigate them. However, errors arising after many repeated shuttles are not yet well documented. Here, we probe decay dynamics contributing to dephasing and relaxation of a singlet-triplet qubit during coherent spin shuttling over many N repeated shuttle operations, in a small external magnetic field B0 ≈ 0−10 mT, and in the absence of a micromagnet. We find that losses are dominated by magnetic dephasing, most visible for small N < 103. However, incoherent spin-flip type shuttle errors become evident for large N > 103. Additionally, we estimate shuttle error rates below 10−4 out to at least N = 103, representing an encouraging figure for future implementations of spin shuttling to entangle distant qubits.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"50 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143824901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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

Landau–Zener without a qubit: multiphoton sidebands interaction and signatures of dissipative quantum chaos 无量子位元的朗道-齐纳：多光子边带相互作用与耗散量子混沌的特征

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-04-07 DOI: 10.1038/s41534-025-00984-4

Léo Peyruchat, Fabrizio Minganti, Marco Scigliuzzo, Filippo Ferrari, Vincent Jouanny, Franco Nori, Vincenzo Savona, Pasquale Scarlino

{"title":"Landau–Zener without a qubit: multiphoton sidebands interaction and signatures of dissipative quantum chaos","authors":"Léo Peyruchat, Fabrizio Minganti, Marco Scigliuzzo, Filippo Ferrari, Vincent Jouanny, Franco Nori, Vincenzo Savona, Pasquale Scarlino","doi":"10.1038/s41534-025-00984-4","DOIUrl":"https://doi.org/10.1038/s41534-025-00984-4","url":null,"abstract":"Landau–Zener–Stückelberg–Majorana (LZSM) interference occurs when qubit parameters are periodically modulated across avoided level crossings. We explore this phenomenon in nonlinear multilevel bosonic systems, where interference is influenced by multiple energy levels. We fabricate two superconducting resonators with flux-tunable Josephson junction arrays. The first device, exhibiting weak nonlinearity, behaves like a linear resonator under weak driving but shows LZSM interference akin to two-level systems. With stronger driving, nonlinear effects alter the interference pattern. We theoretically demonstrate that merging LZSM peaks can lead to dissipative quantum chaos. In the second device, where nonlinearity exceeds photon-loss rates, we observe additional LZSM peaks from Kerr multiphoton resonances. Under Floquet theory, these resonances represent synthetic modes of coupled nonlinear cavities, revealing effective coupling as modulation parameters vary. Our findings advance the understanding of LZSM physics and emphasize the control of nonlinear Floquet states and the emergence of chaos in engineered systems, with significant implications for novel applications in quantum dynamics and quantum control.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"17 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143789692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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