npj Quantum Information最新文献_第3页

Calibrating quantum gates up to 52 qubits in a superconducting processor

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-02-26 DOI: 10.1038/s41534-025-00983-5

Daojin Fan, Guoding Liu, Shaowei Li, Ming Gong, Dachao Wu, Yiming Zhang, Chen Zha, Fusheng Chen, Sirui Cao, Yangsen Ye, Qingling Zhu, Chong Ying, Shaojun Guo, Haoran Qian, Yulin Wu, Hui Deng, Gang Wu, Cheng-Zhi Peng, Xiongfeng Ma, Xiaobo Zhu, Jian-Wei Pan

{"title":"Calibrating quantum gates up to 52 qubits in a superconducting processor","authors":"Daojin Fan, Guoding Liu, Shaowei Li, Ming Gong, Dachao Wu, Yiming Zhang, Chen Zha, Fusheng Chen, Sirui Cao, Yangsen Ye, Qingling Zhu, Chong Ying, Shaojun Guo, Haoran Qian, Yulin Wu, Hui Deng, Gang Wu, Cheng-Zhi Peng, Xiongfeng Ma, Xiaobo Zhu, Jian-Wei Pan","doi":"10.1038/s41534-025-00983-5","DOIUrl":"https://doi.org/10.1038/s41534-025-00983-5","url":null,"abstract":"Benchmarking large-scale quantum gates, typically involving multiple native two-qubit and single-qubit gates, is crucial in quantum computing. Global fidelity, encompassing information about inter-gate correlations, offers a comprehensive metric for evaluating and optimizing gate performance, unlike the fidelities of individual local native gates. In this work, utilizing the character-average benchmarking protocol implementable in a shallow circuit, we successfully benchmark gate fidelities up to 52 qubits. Notably, we achieved a fidelity of 63.09% ± 0.23% for a 44-qubit parallel CZ gate. Utilizing the global fidelity of the parallel CZ gate, we explore the correlations among local CZ gates by introducing an inter-gate correlation metric, enabling one to simultaneously quantify crosstalk error when benchmarking gate fidelity. Finally, we apply our methods in gate optimization. By leveraging global fidelity for optimization, we enhance the fidelity of a 6-qubit parallel CZ gate from 87.65% to 92.04% and decrease the gate correlation from 3.53% to 3.22%, compared to local gate fidelity-based optimization. The experimental results align well with our established composite noise model, incorporating depolarizing and ZZ-coupling noises, and provide valuable insight into further study and mitigation of correlated noise.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"24 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143495518","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

Parameterized quantum comb and simpler circuits for reversing unknown qubit-unitary operations

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-02-24 DOI: 10.1038/s41534-025-00979-1

Yin Mo, Lei Zhang, Yu-Ao Chen, Yingjian Liu, Tengxiang Lin, Xin Wang

{"title":"Parameterized quantum comb and simpler circuits for reversing unknown qubit-unitary operations","authors":"Yin Mo, Lei Zhang, Yu-Ao Chen, Yingjian Liu, Tengxiang Lin, Xin Wang","doi":"10.1038/s41534-025-00979-1","DOIUrl":"https://doi.org/10.1038/s41534-025-00979-1","url":null,"abstract":"Quantum combs play a vital role in characterizing and transforming quantum processes, with wide-ranging applications in quantum information processing. However, obtaining the explicit quantum circuit for the desired quantum comb remains a challenging problem. We propose PQComb, a novel framework that employs parameterized quantum circuits (PQCs) or quantum neural networks to harness the full potential of quantum combs for diverse quantum process transformation tasks. This method is well-suited for near-term quantum devices and can be applied to various tasks in quantum machine learning. As a notable application, we present two streamlined protocols for the time-reversal simulation of unknown qubit unitary evolutions, reducing the ancilla qubit overhead from six to three compared to the previous best-known method. We also extend PQComb to solve the problems of qutrit unitary transformation and channel discrimination. Furthermore, we demonstrate the hardware efficiency and robustness of our qubit unitary inversion protocol under realistic noise simulations of IBM-Q superconducting quantum hardware, yielding a significant improvement in average similarity over the previous protocol under practical regimes. PQComb’s versatility and potential for broader applications in quantum machine learning pave the way for more efficient and practical solutions to complex quantum tasks.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"27 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143477572","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

Check-probe spectroscopy of lifetime-limited emitters in bulk-grown silicon carbide

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-02-22 DOI: 10.1038/s41534-025-00985-3

G. L. van de Stolpe, L. J. Feije, S. J. H. Loenen, A. Das, G. M. Timmer, T. W. de Jong, T. H. Taminiau

{"title":"Check-probe spectroscopy of lifetime-limited emitters in bulk-grown silicon carbide","authors":"G. L. van de Stolpe, L. J. Feije, S. J. H. Loenen, A. Das, G. M. Timmer, T. W. de Jong, T. H. Taminiau","doi":"10.1038/s41534-025-00985-3","DOIUrl":"https://doi.org/10.1038/s41534-025-00985-3","url":null,"abstract":"Solid-state single-photon emitters provide a versatile platform for exploring quantum technologies such as optically connected quantum networks. A key challenge is to ensure the optical coherence and spectral stability of the emitters. Here, we introduce a high-bandwidth ‘check-probe’ scheme to quantitatively measure (laser-induced) spectral diffusion and ionisation rates, as well as homogeneous linewidths. We demonstrate these methods on single V2 centres in commercially available bulk-grown 4H-silicon carbide. Despite observing significant spectral diffusion under laser illumination (≳GHz s−1), the optical transitions are narrow (~35 MHz), and remain stable in the dark (≳1 s). Through Landau-Zener-Stückelberg interferometry, we determine the optical coherence to be near-lifetime limited (T2 = 16.4(4) ns), hinting at the potential for using bulk-grown materials for developing quantum technologies. These results advance our understanding of spectral diffusion of quantum emitters in semiconductor materials, and may have applications for studying charge dynamics across other platforms.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"23 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143473551","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

Direct entanglement detection of quantum systems using machine learning

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-02-20 DOI: 10.1038/s41534-025-00970-w

Yulei Huang, Liangyu Che, Chao Wei, Feng Xu, Xinfang Nie, Jun Li, Dawei Lu, Tao Xin

引用次数: 0

Parallel circuit implementation of variational quantum algorithms

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-02-19 DOI: 10.1038/s41534-025-00982-6

Michele Cattelan, Sheir Yarkoni, Wolfgang Lechner

引用次数: 0

Maximal steady-state entanglement in autonomous quantum thermal machines

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-02-19 DOI: 10.1038/s41534-025-00981-7

Shishir Khandelwal, Björn Annby-Andersson, Giovanni Francesco Diotallevi, Andreas Wacker, Armin Tavakoli

引用次数: 0

Stabilization of Kerr-cat qubits with quantum circuit refrigerator

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-02-15 DOI: 10.1038/s41534-025-00974-6

Shumpei Masuda, Shunsuke Kamimura, Tsuyoshi Yamamoto, Takaaki Aoki, Akiyoshi Tomonaga

引用次数: 0

Contextual subspace variational quantum eigensolver calculation of the dissociation curve of molecular nitrogen on a superconducting quantum computer

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-02-12 DOI: 10.1038/s41534-024-00952-4

Tim Weaving, Alexis Ralli, Peter J. Love, Sauro Succi, Peter V. Coveney

{"title":"Contextual subspace variational quantum eigensolver calculation of the dissociation curve of molecular nitrogen on a superconducting quantum computer","authors":"Tim Weaving, Alexis Ralli, Peter J. Love, Sauro Succi, Peter V. Coveney","doi":"10.1038/s41534-024-00952-4","DOIUrl":"https://doi.org/10.1038/s41534-024-00952-4","url":null,"abstract":"We present an experimental demonstration of the Contextual Subspace Variational Quantum Eigensolver on superconducting hardware. Calculating the potential energy curve of molecular nitrogen proves challenging for many conventional quantum chemistry techniques, since static correlation dominates in the dissociation limit. Our quantum simulations retain good agreement with the Full Configuration Interaction energy, outperforming all benchmarked single-reference wavefunction techniques in capturing the bond-breaking appropriately. Moreover, our methodology is competitive with multiconfigurational approaches but at a saving of quantum resource, meaning larger active spaces can be treated for a fixed qubit allowance. To achieve this result, we deploy an error mitigation/suppression strategy comprised of Dynamical Decoupling, Measurement-Error Mitigation and Zero-Noise Extrapolation. Circuit parallelization also provides passive noise-averaging and improves the effective shot yield to reduce the measurement overhead. Furthermore, we introduce a modified adaptive ansatz construction algorithm that incorporates hardware awareness into our variational circuits, minimizing the transpilation cost for the target qubit topology.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"78 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143393008","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

Remote cooling of spin-ensembles through a spin-mechanical hybrid interface

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-02-07 DOI: 10.1038/s41534-025-00968-4

Yang Wang, Durga Bhaktavatsala Rao Dasari, Jörg Wrachtrup

引用次数: 0

Universal validity of the second law of information thermodynamics

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-02-07 DOI: 10.1038/s41534-024-00922-w

Shintaro Minagawa, M. Hamed Mohammady, Kenta Sakai, Kohtaro Kato, Francesco Buscemi

{"title":"Universal validity of the second law of information thermodynamics","authors":"Shintaro Minagawa, M. Hamed Mohammady, Kenta Sakai, Kohtaro Kato, Francesco Buscemi","doi":"10.1038/s41534-024-00922-w","DOIUrl":"https://doi.org/10.1038/s41534-024-00922-w","url":null,"abstract":"Adiabatic measurements, followed by feedback and erasure protocols, have often been considered as a model to embody Maxwell’s Demon paradox and to study the interplay between thermodynamics and information processing. Such studies have led to the conclusion, now widely accepted in the community, that Maxwell’s Demon and the second law of thermodynamics can peacefully coexist because any gain provided by the demon must be offset by the cost of performing the measurement and resetting the demon’s memory to its initial state. Statements of this kind are collectively referred to as second laws of information thermodynamics and have recently been extended to include quantum theoretical scenarios. However, previous studies in this direction have made several assumptions, particularly about the feedback process and the demon’s memory readout, and thus arrived at statements that are not universally applicable and whose range of validity is not clear. In this work, we fill this gap by precisely characterizing the full range of quantum feedback control and erasure protocols that are overall consistent with the second law of thermodynamics. This leads us to conclude that the second law of information thermodynamics is indeed universal: it must hold for any quantum feedback control and erasure protocol, regardless of the measurement process involved, as long as the protocol is overall compatible with thermodynamics. Our comprehensive analysis not only encompasses new scenarios but also retrieves previous ones, doing so with fewer assumptions. This simplification contributes to a clearer understanding of the theory.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"12 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143258676","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