npj Quantum Information最新文献

Local testability of distance-balanced quantum codes 距离平衡量子密码的局部可测试性

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-11-20 DOI: 10.1038/s41534-024-00908-8

Adam Wills, Ting-Chun Lin, Min-Hsiu Hsieh

引用次数: 0

Optical and spin coherence of Er spin qubits in epitaxial cerium dioxide on silicon 硅基外延二氧化铈中 Er 自旋量子比特的光学和自旋相干性

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-11-20 DOI: 10.1038/s41534-024-00903-z

Jiefei Zhang, Gregory D. Grant, Ignas Masiulionis, Michael T. Solomon, Jonathan C. Marcks, Jasleen K. Bindra, Jens Niklas, Alan M. Dibos, Oleg G. Poluektov, F. Joseph Heremans, Supratik Guha, David D. Awschalom

{"title":"Optical and spin coherence of Er spin qubits in epitaxial cerium dioxide on silicon","authors":"Jiefei Zhang, Gregory D. Grant, Ignas Masiulionis, Michael T. Solomon, Jonathan C. Marcks, Jasleen K. Bindra, Jens Niklas, Alan M. Dibos, Oleg G. Poluektov, F. Joseph Heremans, Supratik Guha, David D. Awschalom","doi":"10.1038/s41534-024-00903-z","DOIUrl":"https://doi.org/10.1038/s41534-024-00903-z","url":null,"abstract":"Robust spin-photon interfaces with optical transitions in the telecommunication band are essential for quantum networking technologies. Erbium (Er) ions are the ideal candidate with environmentally protected transitions in telecom-C band. Finding the right technologically compatible host material to enable long-lived spins remains a major hurdle. We introduce a new platform based on Er ions in cerium dioxide (CeO2) as a nearly-zero nuclear spin environment (0.04%) epitaxially grown on silicon, offering silicon compatibility for opto-electrical devices. Our studies focus on Er3+ ions and show a narrow homogeneous linewidth of 440 kHz with an optical coherence time of 0.72 μs at 3.6 K. The reduced nuclear spin noise enables a slow spin-lattice relaxation with a spin relaxation time up to 2.5 ms and an electron spin coherence time of 0.66 μs (in the isolated ion limit) at 3.6 K. These findings highlight the potential of Er3+:CeO2 platform for quantum networks applications.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"11 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142673914","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

End-to-end variational quantum sensing 端到端变异量子传感

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-11-19 DOI: 10.1038/s41534-024-00914-w

Benjamin MacLellan, Piotr Roztocki, Stefanie Czischek, Roger G. Melko

引用次数: 0

Guarantees on the structure of experimental quantum networks 实验量子网络结构的保证

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-11-14 DOI: 10.1038/s41534-024-00911-z

Andrés Ulibarrena, Jonathan W. Webb, Alexander Pickston, Joseph Ho, Alessandro Fedrizzi, Alejandro Pozas-Kerstjens

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":"1 1","pages":""},"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":"1 1","pages":""},"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":"97 1","pages":""},"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

Classical shadows with Pauli-invariant unitary ensembles 具有保利不变单元集合的经典阴影

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-01-08 DOI: 10.1038/s41534-023-00801-w

Kaifeng Bu, Dax Enshan Koh, Roy J. Garcia, Arthur Jaffe

引用次数: 0

High frequency magnetometry with an ensemble of spin qubits in hexagonal boron nitride 利用六方氮化硼中的自旋量子位组进行高频磁测量

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-01-06 DOI: 10.1038/s41534-023-00796-4

Charlie J. Patrickson, Simon Baber, Blanka B. Gaál, Andrew J. Ramsay, Isaac J. Luxmoore

{"title":"High frequency magnetometry with an ensemble of spin qubits in hexagonal boron nitride","authors":"Charlie J. Patrickson, Simon Baber, Blanka B. Gaál, Andrew J. Ramsay, Isaac J. Luxmoore","doi":"10.1038/s41534-023-00796-4","DOIUrl":"https://doi.org/10.1038/s41534-023-00796-4","url":null,"abstract":"Sensors based on spin qubits in 2D crystals offer the prospect of nanoscale proximities between sensor and source, which could provide access to otherwise inaccessible signals. For AC magnetometry, the sensitivity and frequency range are typically limited by the noise spectrum, which determines the qubit coherence time. We address this using phase modulated continuous concatenated dynamic decoupling, which extends the coherence time towards the T1 limit at room temperature and enables tuneable narrowband AC magnetometry. Using an ensemble of negatively charged boron vacancies in hexagonal boron nitride, we detect out-of-plane AC fields in the range of ~ 10 − 150 MHz, and in-plane fields within ± 150 MHz of the electron spin resonance. We measure an AC magnetic field sensitivity of (sim 1,mu {{{rm{T}}}}/sqrt{{{{rm{Hz}}}}}) at ~ 2.5 GHz, for a sensor volume of ~ 0.1 μm3. This work establishes the viability of spin defects in 2D materials for high frequency magnetometry, with wide-ranging applications across science and technology.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"209 1 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2024-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139110404","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