npj Quantum Information最新文献_第2页

Lower-bounding entanglement in a general Bell scenario 一般贝尔情形下的下限纠缠

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2026-04-15 DOI: 10.1038/s41534-026-01215-0

Liang-Liang Sun, Xiang Zhou, Zhen-Peng Xu, Sixia Yu

引用次数: 0

Fusion-based implementation of qLDPC codes with quantum emitters 基于融合的量子发射体qLDPC码实现

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2026-04-13 DOI: 10.1038/s41534-026-01233-y

Susan X. Chen, Matthias C. Löbl, Ming Lai Chan, Anders S. Sørensen, Stefano Paesani

引用次数: 0

Virtual purification complements quantum error correction in quantum metrology 虚拟净化补充了量子计量中的量子误差校正

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2026-04-09 DOI: 10.1038/s41534-026-01231-0

Hyukgun Kwon, Changhun Oh, Youngrong Lim, Hyunseok Jeong, Seung-Woo Lee, Liang Jiang

{"title":"Virtual purification complements quantum error correction in quantum metrology","authors":"Hyukgun Kwon, Changhun Oh, Youngrong Lim, Hyunseok Jeong, Seung-Woo Lee, Liang Jiang","doi":"10.1038/s41534-026-01231-0","DOIUrl":"https://doi.org/10.1038/s41534-026-01231-0","url":null,"abstract":"Quantum resources enable one to achieve quantum-enhanced estimation sensitivity beyond its classical counterpart. Many studies mainly focus on reducing statistical error, under the assumption that one can always set an unbiased estimator. However, setting an unbiased estimator is not always feasible, especially when one cannot fully characterize noise. Such incomplete noise characterization induces a bias and eventually makes it impossible to attain the enhanced-estimation. In this work, we explore two systematic approaches; quantum error correction (QEC) and the virtual purification (VP) to reduce the bias, and compare their performance. First, we show that when the noise is indistinguishable from the signal, QEC cannot reduce the bias since it is impossible to construct a QEC code that corrects the noise while preserving the signal. We then show that VP can mitigate indistinguishable error that eventually enable a more accurate estimation compared to QEC. Our findings reveal that VP offers a robust alternative to QEC in scenarios where indistinguishable errors pose significant challenges. We then demonstrate that VP with a stabilizer state probe can efficiently suppress the bias under local depolarizing noise, thereby yielding a significant improvement in estimation performance compared to the QEC-based approach.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"131 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147655976","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

Nonlocality, integrability and quantum chaos in the spectrum of bell operators 钟算子谱中的非局域性、可积性和量子混沌

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2026-04-06 DOI: 10.1038/s41534-026-01232-z

Albert Aloy, Guillem Müller-Rigat, Maciej Lewenstein, Jordi Tura, Matteo Fadel

{"title":"Nonlocality, integrability and quantum chaos in the spectrum of bell operators","authors":"Albert Aloy, Guillem Müller-Rigat, Maciej Lewenstein, Jordi Tura, Matteo Fadel","doi":"10.1038/s41534-026-01232-z","DOIUrl":"https://doi.org/10.1038/s41534-026-01232-z","url":null,"abstract":"We introduce a permutationally invariant multipartite Bell inequality for many-body three-level systems and use it to investigate a connection between Bell nonlocality and (lack of) quantum chaos. An associated Bell operator is then defined via Born’s rule, mapping the conditional probabilities of the Bell inequality to quantum measurement operators. This allows us to interpret the Bell operator as an effective Hamiltonian, which we use to analyze its spectral statistics across different SU(3) irreducible representations and measurement choices. Surprisingly, we find that, in every irreducible representation exhibiting nonlocality, the measurement settings yielding maximal violation result in a Bell operator with Poissonian level statistics, thus signaling integrable behavior. This integrability is both unique and fragile, since generic or slightly perturbed measurements lead to the Wigner-Dyson statistics associated with chaotic behavior. Through further analysis, we are able to identify an emergent parity symmetry in the Bell operator near the point of maximal violation, providing an explanation for the observed regularity in the spectrum. These results suggest a deep interplay between optimal quantum measurements, non-local correlations, and integrability, opening new perspectives at the intersection of Bell nonlocality and quantum chaos.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"29 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2026-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147619881","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

Contractive unitary and classical shadow tomography 缩正和经典影层析成像

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2026-04-04 DOI: 10.1038/s41534-026-01227-w

Yadong Wu, Ce Wang, Juan Yao, Hui Zhai, Yi-Zhuang You, Pengfei Zhang

引用次数: 0

Distributed quantum sensing with measurement-after-interaction strategies 基于交互后测量策略的分布式量子传感

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2026-04-03 DOI: 10.1038/s41534-026-01224-z

Jiajie Guo, Shuheng Liu, Matteo Fadel, Qiongyi He

引用次数: 0

Quantum cryptanalysis of SPN ciphers with known plaintext 已知明文的SPN密码的量子密码分析

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2026-04-01 DOI: 10.1038/s41534-026-01218-x

Uroosa Kiran, Aneela Safdar, Saif Ullah Khalid, Hammad Tanveer Butt, Zunera Jalil

{"title":"Quantum cryptanalysis of SPN ciphers with known plaintext","authors":"Uroosa Kiran, Aneela Safdar, Saif Ullah Khalid, Hammad Tanveer Butt, Zunera Jalil","doi":"10.1038/s41534-026-01218-x","DOIUrl":"https://doi.org/10.1038/s41534-026-01218-x","url":null,"abstract":"Key recovery attack on SPN ciphers such as AES is NP hard in complexity. Previous studies have estimated the quantum resources required for implementing Grover’s key search for AES, but these are largely theoretical in nature. The key challenges to implement Grover’s algorithm on current quantum hardware include the number of available qubits, noise, and decoherence. However, the rapid advancement of hardware has brought us closer to practical realization for the cryptanalysis of light-weight SPN ciphers. This study presents an efficient quantum circuit implementation of Mini-AES, a 16-bit variant of AES, employing standard CNOT and Toffoli gates. To the best of our knowledge, our work provides the first complete quantum implementations of all core Mini-AES components for the quantum oracle. The effects of noise are emulated for each module of the quantum oracle and quantified. Furthermore, Grover’s algorithm is applied to Mini-AES to perform successful key recovery through a known-plaintext attack, demonstrating significant amplitude amplification while using near-optimal Grover’s iterations, thereby reducing the total quantum volume. The optimal Grover’s iterations have been obtained empirically as well as validated with finite-shot analysis. Notably, the application of Grover’s algorithm reveals key clustering behavior in Mini-AES, which has been corroborated through classical simulation.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"99 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147585938","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

Fiber-integrated quantum frequency conversion for long-distance quantum networking 用于远距离量子网络的光纤集成量子变频

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2026-03-31 DOI: 10.1038/s41534-026-01225-y

Zhichuan Liao, Ao Shen, Lai Zhou, Nan Jiang, Zhiliang Yuan

{"title":"Fiber-integrated quantum frequency conversion for long-distance quantum networking","authors":"Zhichuan Liao, Ao Shen, Lai Zhou, Nan Jiang, Zhiliang Yuan","doi":"10.1038/s41534-026-01225-y","DOIUrl":"https://doi.org/10.1038/s41534-026-01225-y","url":null,"abstract":"Signal photons emitted by quantum nodes typically fall outside the low-loss telecom window of optical fibers, leading to severe transmission losses. Quantum frequency conversion (QFC) offers an effective optical interface that bridges quantum nodes with telecom-band channels, enabling long-distance quantum communication. In this work, we demonstrate a compact, fiber-integrated QFC system with low noise and a high signal-to-noise ratio (SNR). Using a periodically poled lithium niobate (PPLN) waveguide, input photons at 637.2 nm are down-converted to telecom photons at 1588.3 nm. Our system achieves a total conversion efficiency of approximately 9%, with pump-induced noise suppressed to 154 Hz. For input photon rates of 32.7, 118.0, and 327.7 kHz, the corresponding SNRs are 12.3, 43.9, and 117.8, respectively. We further develop a theoretical model to simulate the entanglement fidelity between nitrogen-vacancy (NV) center spins and the frequency-converted telecom photons. At the emission rate of an NV center, our QFC system maintains an expected fidelity exceeding 52% over a transmission distance of 100 km. These findings highlight the potential of our QFC system for scalable, long-distance quantum networking.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"18 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2026-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147585947","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

Scalable conflict-free bandit algorithm using a quantum optical setup 使用量子光学设置的可扩展无冲突强盗算法

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2026-03-30 DOI: 10.1038/s41534-026-01201-6

Kohei Konaka, André Röhm, Takatomo Mihana, Ryoichi Horisaki

引用次数: 0

On the constant depth implementation of Pauli exponentials 泡利指数的等深度实现

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2026-03-28 DOI: 10.1038/s41534-026-01226-x

Ioana Moflic, Alexandru Paler

引用次数: 0