npj Quantum Information最新文献_第10页

Quantum state preparation of normal distributions using matrix product states 利用矩阵乘积状态制备正态分布的量子态

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-01-25 DOI: 10.1038/s41534-024-00805-0

Jason Iaconis, Sonika Johri, Elton Yechao Zhu

引用次数: 0

Three-dimensional magnetic resonance tomography with sub-10 nanometer resolution 分辨率低于 10 纳米的三维磁共振断层成像技术

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-01-25 DOI: 10.1038/s41534-024-00809-w

Mohammad T. Amawi, Andrii Trelin, You Huang, Paul Weinbrenner, Francesco Poggiali, Joachim Leibold, Martin Schalk, Friedemann Reinhard

引用次数: 0

Valid and efficient entanglement verification with finite copies of a quantum state 利用量子态的有限副本进行有效且高效的纠缠验证

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-01-24 DOI: 10.1038/s41534-024-00810-3

Paweł Cieśliński, Jan Dziewior, Lukas Knips, Waldemar Kłobus, Jasmin Meinecke, Tomasz Paterek, Harald Weinfurter, Wiesław Laskowski

引用次数: 0

Topological single-photon emission from quantum emitter chains 量子发射器链的拓扑单光子发射

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-01-23 DOI: 10.1038/s41534-024-00807-y

Yubin Wang, Huawen Xu, Xinyi Deng, Timothy C. H. Liew, Sanjib Ghosh, Qihua Xiong

引用次数: 0

Quantum LOSR networks cannot generate graph states with high fidelity 量子 LOSR 网络无法高保真地生成图状态

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-01-22 DOI: 10.1038/s41534-024-00806-z

Yi-Xuan Wang, Zhen-Peng Xu, Otfried Gühne

引用次数: 0

Theoretical guarantees for permutation-equivariant quantum neural networks 包换量子神经网络的理论保证

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-01-22 DOI: 10.1038/s41534-024-00804-1

Louis Schatzki, Martín Larocca, Quynh T. Nguyen, Frédéric Sauvage, M. Cerezo

{"title":"Theoretical guarantees for permutation-equivariant quantum neural networks","authors":"Louis Schatzki, Martín Larocca, Quynh T. Nguyen, Frédéric Sauvage, M. Cerezo","doi":"10.1038/s41534-024-00804-1","DOIUrl":"https://doi.org/10.1038/s41534-024-00804-1","url":null,"abstract":"Despite the great promise of quantum machine learning models, there are several challenges one must overcome before unlocking their full potential. For instance, models based on quantum neural networks (QNNs) can suffer from excessive local minima and barren plateaus in their training landscapes. Recently, the nascent field of geometric quantum machine learning (GQML) has emerged as a potential solution to some of those issues. The key insight of GQML is that one should design architectures, such as equivariant QNNs, encoding the symmetries of the problem at hand. Here, we focus on problems with permutation symmetry (i.e., symmetry group Sn), and show how to build Sn-equivariant QNNs We provide an analytical study of their performance, proving that they do not suffer from barren plateaus, quickly reach overparametrization, and generalize well from small amounts of data. To verify our results, we perform numerical simulations for a graph state classification task. Our work provides theoretical guarantees for equivariant QNNs, thus indicating the power and potential of GQML.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":null,"pages":null},"PeriodicalIF":7.6,"publicationDate":"2024-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139522513","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

Hong-Ou-Mandel interference of single-photon-level pulses stored in independent room-temperature quantum memories 存储在独立室温量子存储器中的单光子级脉冲的弘欧-曼德尔干涉

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-01-15 DOI: 10.1038/s41534-024-00803-2

Sonali Gera, Chase Wallace, Mael Flament, Alessia Scriminich, Mehdi Namazi, Youngshin Kim, Steven Sagona-Stophel, Giuseppe Vallone, Paolo Villoresi, Eden Figueroa

{"title":"Hong-Ou-Mandel interference of single-photon-level pulses stored in independent room-temperature quantum memories","authors":"Sonali Gera, Chase Wallace, Mael Flament, Alessia Scriminich, Mehdi Namazi, Youngshin Kim, Steven Sagona-Stophel, Giuseppe Vallone, Paolo Villoresi, Eden Figueroa","doi":"10.1038/s41534-024-00803-2","DOIUrl":"https://doi.org/10.1038/s41534-024-00803-2","url":null,"abstract":"Quantum repeater networks require independent absorptive quantum memories capable of storing and retrieving indistinguishable photons to perform high-repetition entanglement swapping operations. The ability to perform these coherent operations at room temperature is of prime importance for the realization of scalable quantum networks. We perform Hong-Ou-Mandel (HOM) interference between photonic polarization states and single-photon-level pulses stored and retrieved from two sets of independent room-temperature quantum memories. We show that the storage and retrieval of polarization states from quantum memories does not degrade the HOM visibility for few-photon-level polarization states in a dual-rail configuration. For single-photon-level pulses, we measure the HOM visibility with various levels of background in a single polarization, single-rail QM, and investigate its dependence on the signal-to-background ratio. We obtain an HOM visibility of 43%, compared to the 48% no-memory limit of our set-up. These results allow us to estimate a 33% visibility for polarization qubits under the same conditions. These demonstrations lay the groundwork for future applications using large-scale memory-assisted quantum networks.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":null,"pages":null},"PeriodicalIF":7.6,"publicationDate":"2024-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139474172","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

Experimental graybox quantum system identification and control 灰箱量子系统识别与控制实验

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-01-13 DOI: 10.1038/s41534-023-00795-5

Akram Youssry, Yang Yang, Robert J. Chapman, Ben Haylock, Francesco Lenzini, Mirko Lobino, Alberto Peruzzo

{"title":"Experimental graybox quantum system identification and control","authors":"Akram Youssry, Yang Yang, Robert J. Chapman, Ben Haylock, Francesco Lenzini, Mirko Lobino, Alberto Peruzzo","doi":"10.1038/s41534-023-00795-5","DOIUrl":"https://doi.org/10.1038/s41534-023-00795-5","url":null,"abstract":"Understanding and controlling engineered quantum systems is key to developing practical quantum technology. However, given the current technological limitations, such as fabrication imperfections and environmental noise, this is not always possible. To address these issues, a great deal of theoretical and numerical methods for quantum system identification and control have been developed. These methods range from traditional curve fittings, which are limited by the accuracy of the model that describes the system, to machine learning (ML) methods, which provide efficient control solutions but no control beyond the output of the model, nor insights into the underlying physical process. Here we experimentally demonstrate a ‘graybox’ approach to construct a physical model of a quantum system and use it to design optimal control. We report superior performance over model fitting, while generating unitaries and Hamiltonians, which are quantities not available from the structure of standard supervised ML models. Our approach combines physics principles with high-accuracy ML and is effective with any problem where the required controlled quantities cannot be directly measured in experiments. This method naturally extends to time-dependent and open quantum systems, with applications in quantum noise spectroscopy and cancellation.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":null,"pages":null},"PeriodicalIF":7.6,"publicationDate":"2024-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139435349","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

Hamiltonian phase error in resonantly driven CNOT gate above the fault-tolerant threshold 高于容错阈值的谐振驱动 CNOT 栅极的哈密顿相位误差

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-01-11 DOI: 10.1038/s41534-023-00802-9

Yi-Hsien Wu, Leon C. Camenzind, Akito Noiri, Kenta Takeda, Takashi Nakajima, Takashi Kobayashi, Chien-Yuan Chang, Amir Sammak, Giordano Scappucci, Hsi-Sheng Goan, Seigo Tarucha

{"title":"Hamiltonian phase error in resonantly driven CNOT gate above the fault-tolerant threshold","authors":"Yi-Hsien Wu, Leon C. Camenzind, Akito Noiri, Kenta Takeda, Takashi Nakajima, Takashi Kobayashi, Chien-Yuan Chang, Amir Sammak, Giordano Scappucci, Hsi-Sheng Goan, Seigo Tarucha","doi":"10.1038/s41534-023-00802-9","DOIUrl":"https://doi.org/10.1038/s41534-023-00802-9","url":null,"abstract":"Because of their long coherence time and compatibility with industrial foundry processes, electron spin qubits are a promising platform for scalable quantum processors. A full-fledged quantum computer will need quantum error correction, which requires high-fidelity quantum gates. Analyzing and mitigating gate errors are useful to improve gate fidelity. Here, we demonstrate a simple yet reliable calibration procedure for a high-fidelity controlled-rotation gate in an exchange-always-on Silicon quantum processor, allowing operation above the fault-tolerance threshold of quantum error correction. We find that the fidelity of our uncalibrated controlled-rotation gate is limited by coherent errors in the form of controlled phases and present a method to measure and correct these phase errors. We then verify the improvement in our gate fidelities by randomized benchmark and gate-set tomography protocols. Finally, we use our phase correction protocol to implement a virtual, high-fidelity, controlled-phase gate.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":null,"pages":null},"PeriodicalIF":7.6,"publicationDate":"2024-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139431152","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

Extending loophole-free nonlocal correlations to arbitrarily large distances 将无漏洞非局部相关性扩展到任意大距离

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-01-11 DOI: 10.1038/s41534-023-00799-1

Anubhav Chaturvedi, Giuseppe Viola, Marcin Pawłowski

引用次数: 0