npj Quantum Information最新文献_第4页

Microscopic parametrizations for gate set tomography under coloured noise

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-02-06 DOI: 10.1038/s41534-025-00976-4

P. Viñas, A. Bermudez

引用次数: 0

Low-error encoder for time-bin and decoy states for quantum key distribution

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-02-06 DOI: 10.1038/s41534-024-00923-9

Davide Scalcon, Elisa Bazzani, Giuseppe Vallone, Paolo Villoresi, Marco Avesani

引用次数: 0

Scalable temporal multiplexing of telecom photons via thin-film lithium niobate photonics

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-02-06 DOI: 10.1038/s41534-024-00929-3

Çağın Ekici, Yonghe Yu, Jeremy C. Adcock, Alif Laila Muthali, Mujtaba Zahidy, Heyun Tan, Zhongjin Lin, Hao Li, Leif K. Oxenløwe, Xinlun Cai, Yunhong Ding

{"title":"Scalable temporal multiplexing of telecom photons via thin-film lithium niobate photonics","authors":"Çağın Ekici, Yonghe Yu, Jeremy C. Adcock, Alif Laila Muthali, Mujtaba Zahidy, Heyun Tan, Zhongjin Lin, Hao Li, Leif K. Oxenløwe, Xinlun Cai, Yunhong Ding","doi":"10.1038/s41534-024-00929-3","DOIUrl":"https://doi.org/10.1038/s41534-024-00929-3","url":null,"abstract":"Efficient single-photon generation remains a big challenge in quantum photonics. A promising approach to overcome this challenge is to employ active multiplexing—repeating a nondeterministic photon pair generation process across orthogonal degrees of freedom and exploiting heralding to actively route the heralded photon to the desired single output mode via feedforward. The main barriers of multiplexing schemes, however, are minimizing resource requirements to allow scalability and the lack of availability of high-speed, low-loss switches. Here, we present an on-chip temporal multiplexing scheme utilizing thin-film lithium niobate (TFLN) photonics to effectively address these challenges. Our time-multiplexed source, operating at a rate of 62.2 MHz, enhances single-photon probability by a factor of 3.37 ± 0.05 without introducing additional multi-photon noise. This demonstration highlights the feasibility and potential of TFLN photonics for large-scale complex quantum information technologies.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"31 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143191972","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

State estimation with quantum extreme learning machines beyond the scrambling time

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-02-03 DOI: 10.1038/s41534-024-00927-5

Marco Vetrano, Gabriele Lo Monaco, Luca Innocenti, Salvatore Lorenzo, G. Massimo Palma

引用次数: 0

Programmable quantum circuits in a large-scale photonic waveguide array

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-02-03 DOI: 10.1038/s41534-024-00934-6

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

引用次数: 0

Tantalum airbridges for scalable superconducting quantum processors

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-01-29 DOI: 10.1038/s41534-025-00972-8

Kunliang Bu, Sainan Huai, Zhenxing Zhang, Dengfeng Li, Yuan Li, Jingjing Hu, Xiaopei Yang, Maochun Dai, Tianqi Cai, Yi-Cong Zheng, Shengyu Zhang

{"title":"Tantalum airbridges for scalable superconducting quantum processors","authors":"Kunliang Bu, Sainan Huai, Zhenxing Zhang, Dengfeng Li, Yuan Li, Jingjing Hu, Xiaopei Yang, Maochun Dai, Tianqi Cai, Yi-Cong Zheng, Shengyu Zhang","doi":"10.1038/s41534-025-00972-8","DOIUrl":"https://doi.org/10.1038/s41534-025-00972-8","url":null,"abstract":"The unique property of tantalum, particularly its exceptional resistance to both acid and alkali, makes it promising for superconducting quantum processors. Here, we propose a novel lift-off method for fabricating tantalum airbridges with separate or fully-capped structures. This method introduces an aluminum film as a barrier layer to separate two layers of photoresist, which is then etched away before depositing tantalum film. We experimentally characterize these tantalum airbridges as control line jumpers, ground plane crossovers and coupling elements, and further validate the overall adaptability by a 13-qubit quantum processor with a median T1 exceeding 100 μs. The median single-qubit gate fidelity is measured at 99.95(2)% for isolated Randomized Benchmarking and 99.94(2)% for the simultaneous one. Additionally, the experimental achievement of airbridge coupling with a controlled-Z gate fidelity surpassing 99.2(2)% in a separate two-qubit quantum chip may facilitate scalable quantum computation and quantum error correction with entirely tantalum elements.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"1245 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143054862","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

Gate modulation of the hole singlet-triplet qubit frequency in germanium

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-01-29 DOI: 10.1038/s41534-024-00953-3

John Rooney, Zhentao Luo, Lucas E. A. Stehouwer, Giordano Scappucci, Menno Veldhorst, Hong-Wen Jiang

{"title":"Gate modulation of the hole singlet-triplet qubit frequency in germanium","authors":"John Rooney, Zhentao Luo, Lucas E. A. Stehouwer, Giordano Scappucci, Menno Veldhorst, Hong-Wen Jiang","doi":"10.1038/s41534-024-00953-3","DOIUrl":"https://doi.org/10.1038/s41534-024-00953-3","url":null,"abstract":"Spin qubits in germanium gate-defined quantum dots have made considerable progress within the last few years, partially due to their strong spin-orbit coupling and site-dependent g-tensors. While this characteristic of the g-factors removes the need for micromagnets and allows for the possibility of all-electric qubit control, relying on these g-tensors necessitates the need to understand their sensitivity to the confinement potential that defines the quantum dots. Here, we demonstrate a S − T_ qubit whose frequency is a strong function of the voltage applied to the barrier gate shared by the quantum dots. We find a g-factor that can be approximately increased by an order of magnitude adjusting the barrier gate voltage only by 12 mV. We show how this strong dependence could potentially be attributed to the dots moving through a variable strain environment in our device. This work not only reinforces previous findings that site-dependent g-tensors in germanium can be utilized for qubit manipulation, but reveals the sensitivity and tunability these g-tensors have to the electrostatic confinement of the quantum dot.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"37 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143054863","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

High-dimensional coherent one-way quantum key distribution

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-01-29 DOI: 10.1038/s41534-025-00965-7

Kfir Sulimany, Guy Pelc, Rom Dudkiewicz, Simcha Korenblit, Hagai S. Eisenberg, Yaron Bromberg, Michael Ben-Or

{"title":"High-dimensional coherent one-way quantum key distribution","authors":"Kfir Sulimany, Guy Pelc, Rom Dudkiewicz, Simcha Korenblit, Hagai S. Eisenberg, Yaron Bromberg, Michael Ben-Or","doi":"10.1038/s41534-025-00965-7","DOIUrl":"https://doi.org/10.1038/s41534-025-00965-7","url":null,"abstract":"High-dimensional quantum key distribution (QKD) offers secure communication with key rates that surpass those of QKD protocols utilizing two-dimensional encoding. However, existing high-dimensional QKD protocols require additional experimental resources, such as multiport interferometers and multiple detectors, thereby increasing the cost of high-dimensional systems and limiting their use. We introduce and analyze a high-dimensional QKD protocol that requires only standard two-dimensional hardware. We provide security analysis against individual and coherent attacks, establishing upper and lower bounds on the secure key rates. We tested our protocol on a standard two-dimensional QKD system over a 40 km fiber link, achieving a twofold increase in secure key rate compared to the standard two-dimensional coherent one-way protocol, without any hardware modifications. This work offers a significant improvement in the performance of already deployed QKD systems through simple software updates and holds broad applicability across various QKD schemes, making high-dimensional QKD practical for widespread use.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"26 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143054861","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

Mitigating errors in analog quantum simulation by Hamiltonian reshaping or Hamiltonian rescaling

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-01-28 DOI: 10.1038/s41534-025-00969-3

Rui-Cheng Guo, Yanwu Gu, Dong E. Liu

{"title":"Mitigating errors in analog quantum simulation by Hamiltonian reshaping or Hamiltonian rescaling","authors":"Rui-Cheng Guo, Yanwu Gu, Dong E. Liu","doi":"10.1038/s41534-025-00969-3","DOIUrl":"https://doi.org/10.1038/s41534-025-00969-3","url":null,"abstract":"Simulating quantum many-body systems is crucial for advancing physics but poses substantial challenges for classical computers. Quantum simulations overcome these limitations, with analog simulators offering unique advantages over digital methods, such as lower systematic errors and reduced circuit depth, making them efficient for studying complex quantum phenomena. However, unlike their digital counterparts, analog quantum simulations face significant limitations due to the absence of effective error mitigation techniques. This work introduces two novel error mitigation strategies—Hamiltonian reshaping and Hamiltonian rescaling—in analog quantum simulation for tasks like eigen-energy evaluation. Hamiltonian reshaping uses random unitary transformations to generate new Hamiltonians with identical eigenvalues but varied eigenstates, allowing error reduction through averaging. Hamiltonian rescaling mitigates errors by comparing eigenvalue estimates from energy-scaled Hamiltonians. Numerical calculations validate both methods, demonstrating their significant practical effectiveness in enhancing the accuracy and reliability of analog quantum simulators.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"25 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143049901","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

Codes for entanglement-assisted classical communication

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2025-01-27 DOI: 10.1038/s41534-024-00954-2

Tushita Prasad, Markus Grassl

引用次数: 0