npj Quantum Information最新文献_第8页

Fourier transform noise spectroscopy 傅立叶变换噪声光谱

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-05-17 DOI: 10.1038/s41534-024-00841-w

Arian Vezvaee, Nanako Shitara, Shuo Sun, Andrés Montoya-Castillo

{"title":"Fourier transform noise spectroscopy","authors":"Arian Vezvaee, Nanako Shitara, Shuo Sun, Andrés Montoya-Castillo","doi":"10.1038/s41534-024-00841-w","DOIUrl":"https://doi.org/10.1038/s41534-024-00841-w","url":null,"abstract":"Spectral characterization of noise environments that lead to the decoherence of qubits is critical to developing robust quantum technologies. While dynamical decoupling offers one of the most successful approaches to characterize noise spectra, it necessitates applying large sequences of π pulses that increase the complexity and cost of the method. Here, we introduce a noise spectroscopy method that utilizes only the Fourier transform of free induction decay or spin echo measurements, thus removing the need for the application many π pulses. We show that our method faithfully recovers the correct noise spectra for a variety of different environments (including 1/f-type noise) and outperforms previous dynamical decoupling schemes while significantly reducing their experimental overhead. We also discuss the experimental feasibility of our proposal and demonstrate its robustness in the presence of statistical measurement error. Our method is applicable to a wide range of quantum platforms and provides a simpler path toward a more accurate spectral characterization of quantum devices, thus offering possibilities for tailored decoherence mitigation.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"59 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2024-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140954032","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-fidelity four-photon GHZ states on chip 芯片上的高保真四光子 GHZ 状态

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-05-15 DOI: 10.1038/s41534-024-00830-z

Mathias Pont, Giacomo Corrielli, Andreas Fyrillas, Iris Agresti, Gonzalo Carvacho, Nicolas Maring, Pierre-Emmanuel Emeriau, Francesco Ceccarelli, Ricardo Albiero, Paulo Henrique Dias Ferreira, Niccolo Somaschi, Jean Senellart, Isabelle Sagnes, Martina Morassi, Aristide Lemaître, Pascale Senellart, Fabio Sciarrino, Marco Liscidini, Nadia Belabas, Roberto Osellame

{"title":"High-fidelity four-photon GHZ states on chip","authors":"Mathias Pont, Giacomo Corrielli, Andreas Fyrillas, Iris Agresti, Gonzalo Carvacho, Nicolas Maring, Pierre-Emmanuel Emeriau, Francesco Ceccarelli, Ricardo Albiero, Paulo Henrique Dias Ferreira, Niccolo Somaschi, Jean Senellart, Isabelle Sagnes, Martina Morassi, Aristide Lemaître, Pascale Senellart, Fabio Sciarrino, Marco Liscidini, Nadia Belabas, Roberto Osellame","doi":"10.1038/s41534-024-00830-z","DOIUrl":"https://doi.org/10.1038/s41534-024-00830-z","url":null,"abstract":"Mutually entangled multi-photon states are at the heart of all-optical quantum technologies. While impressive progresses have been reported in the generation of such quantum light states using free space apparatus, high-fidelity high-rate on-chip entanglement generation is crucial for future scalability. In this work, we use a bright quantum-dot based single-photon source to demonstrate the high fidelity generation of 4-photon Greenberg-Horne-Zeilinger (GHZ) states with a low-loss reconfigurable glass photonic circuit. We reconstruct the density matrix of the generated states using full quantum-state tomography reaching an experimental fidelity to the target state of ({{{{mathcal{F}}}}}_{{{{{rm{GHZ}}}}}_{4}}=(86.0pm 0.4), %), and a purity of ({{{{mathcal{P}}}}}_{{{{{rm{GHZ}}}}}_{4}}=(76.3pm 0.6), %). The entanglement of the generated states is certified with a semi device-independent approach through the violation of a Bell-like inequality by more than 39 standard deviations. Finally, we carry out a four-partite quantum secret sharing protocol on-chip where a regulator shares with three interlocutors a sifted key with up to 1978 bits, achieving a qubit-error rate of 10.87%. These results establish that the quantum-dot technology combined with glass photonic circuitry offers a viable path for entanglement generation and distribution.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"45 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140949601","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

Fourier Quantum Process Tomography 傅立叶量子过程断层扫描

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-05-09 DOI: 10.1038/s41534-024-00844-7

Francesco Di Colandrea, Nazanin Dehghan, Alessio D’Errico, Ebrahim Karimi

引用次数: 0

Engineering holography with stabilizer graph codes 使用稳定器图码的工程全息技术

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-05-03 DOI: 10.1038/s41534-024-00822-z

Gerard Anglès Munné, Valentin Kasper, Felix Huber

引用次数: 0

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-04-30 DOI: 10.1038/s41534-024-00842-9

Ji Zou, Stefano Bosco, Daniel Loss

{"title":"Spatially correlated classical and quantum noise in driven qubits","authors":"Ji Zou, Stefano Bosco, Daniel Loss","doi":"10.1038/s41534-024-00842-9","DOIUrl":"https://doi.org/10.1038/s41534-024-00842-9","url":null,"abstract":"Correlated noise across multiple qubits poses a significant challenge for achieving scalable and fault-tolerant quantum processors. Despite recent experimental efforts to quantify this noise in various qubit architectures, a comprehensive understanding of its role in qubit dynamics remains elusive. Here, we present an analytical study of the dynamics of driven qubits under spatially correlated noise, including both Markovian and non-Markovian noise. Surprisingly, we find that by operating the qubit system at low temperatures, where correlated quantum noise plays an important role, significant long-lived entanglement between qubits can be generated. Importantly, this generation process can be controlled on-demand by turning the qubit driving on and off. On the other hand, we demonstrate that by operating the system at a higher temperature, the crosstalk between qubits induced by the correlated noise is unexpectedly suppressed. We finally reveal the impact of spatio-temporally correlated 1/f noise on the decoherence rate, and how its temporal correlations restore lost entanglement. Our findings provide critical insights into not only suppressing crosstalk between qubits caused by correlated noise but also in effectively leveraging such noise as a beneficial resource for controlled entanglement generation.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"61 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140817943","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

Optimal quantum key distribution networks: capacitance versus security 最佳量子密钥分发网络：电容与安全性

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-04-29 DOI: 10.1038/s41534-024-00828-7

Lorenzo Cirigliano, Valentina Brosco, Claudio Castellano, Claudio Conti, Laura Pilozzi

引用次数: 0

Hunting for quantum-classical crossover in condensed matter problems 在凝聚态问题中寻找量子经典交叉

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-04-29 DOI: 10.1038/s41534-024-00839-4

Nobuyuki Yoshioka, Tsuyoshi Okubo, Yasunari Suzuki, Yuki Koizumi, Wataru Mizukami

{"title":"Hunting for quantum-classical crossover in condensed matter problems","authors":"Nobuyuki Yoshioka, Tsuyoshi Okubo, Yasunari Suzuki, Yuki Koizumi, Wataru Mizukami","doi":"10.1038/s41534-024-00839-4","DOIUrl":"https://doi.org/10.1038/s41534-024-00839-4","url":null,"abstract":"The intensive pursuit for quantum advantage in terms of computational complexity has further led to a modernized crucial question of when and how will quantum computers outperform classical computers. The next milestone is undoubtedly the realization of quantum acceleration in practical problems. Here we provide a clear evidence and arguments that the primary target is likely to be condensed matter physics. Our primary contributions are summarized as follows: 1) Proposal of systematic error/runtime analysis on state-of-the-art classical algorithm based on tensor networks; 2) Dedicated and high-resolution analysis on quantum resource performed at the level of executable logical instructions; 3) Clarification of quantum-classical crosspoint for ground-state simulation to be within runtime of hours using only a few hundreds of thousand physical qubits for 2d Heisenberg and 2d Fermi-Hubbard models, assuming that logical qubits are encoded via the surface code with the physical error rate of p = 10−3. To our knowledge, we argue that condensed matter problems offer the earliest platform for demonstration of practical quantum advantage that is order-of-magnitude more feasible than ever known candidates, in terms of both qubit counts and total runtime.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"81 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140814594","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

Systematic improvements in transmon qubit coherence enabled by niobium surface encapsulation 通过铌表面封装系统地改善跨文量子比特相干性

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-04-26 DOI: 10.1038/s41534-024-00840-x

Mustafa Bal, Akshay A. Murthy, Shaojiang Zhu, Francesco Crisa, Xinyuan You, Ziwen Huang, Tanay Roy, Jaeyel Lee, David van Zanten, Roman Pilipenko, Ivan Nekrashevich, Andrei Lunin, Daniel Bafia, Yulia Krasnikova, Cameron J. Kopas, Ella O. Lachman, Duncan Miller, Josh Y. Mutus, Matthew J. Reagor, Hilal Cansizoglu, Jayss Marshall, David P. Pappas, Kim Vu, Kameshwar Yadavalli, Jin-Su Oh, Lin Zhou, Matthew J. Kramer, Florent Lecocq, Dominic P. Goronzy, Carlos G. Torres-Castanedo, P. Graham Pritchard, Vinayak P. Dravid, James M. Rondinelli, Michael J. Bedzyk, Mark C. Hersam, John Zasadzinski, Jens Koch, James A. Sauls, Alexander Romanenko, Anna Grassellino

{"title":"Systematic improvements in transmon qubit coherence enabled by niobium surface encapsulation","authors":"Mustafa Bal, Akshay A. Murthy, Shaojiang Zhu, Francesco Crisa, Xinyuan You, Ziwen Huang, Tanay Roy, Jaeyel Lee, David van Zanten, Roman Pilipenko, Ivan Nekrashevich, Andrei Lunin, Daniel Bafia, Yulia Krasnikova, Cameron J. Kopas, Ella O. Lachman, Duncan Miller, Josh Y. Mutus, Matthew J. Reagor, Hilal Cansizoglu, Jayss Marshall, David P. Pappas, Kim Vu, Kameshwar Yadavalli, Jin-Su Oh, Lin Zhou, Matthew J. Kramer, Florent Lecocq, Dominic P. Goronzy, Carlos G. Torres-Castanedo, P. Graham Pritchard, Vinayak P. Dravid, James M. Rondinelli, Michael J. Bedzyk, Mark C. Hersam, John Zasadzinski, Jens Koch, James A. Sauls, Alexander Romanenko, Anna Grassellino","doi":"10.1038/s41534-024-00840-x","DOIUrl":"https://doi.org/10.1038/s41534-024-00840-x","url":null,"abstract":"We present a transmon qubit fabrication technique that yields systematic improvements in T1 relaxation times. We encapsulate the surface of niobium and prevent the formation of its lossy surface oxide. By maintaining the same superconducting metal and only varying the surface, this comparative investigation examining different capping materials, such as tantalum, aluminum, titanium nitride, and gold, as well as substrates across different qubit foundries demonstrates the detrimental impact that niobium oxides have on coherence times of superconducting qubits, compared to native oxides of tantalum, aluminum or titanium nitride. Our surface-encapsulated niobium qubit devices exhibit T1 relaxation times 2–5 times longer than baseline qubit devices with native niobium oxides. When capping niobium with tantalum, we obtain median qubit lifetimes above 300 μs, with maximum values up to 600 μs. Our comparative structural and chemical analysis provides insight into why amorphous niobium oxides may induce higher losses compared to other amorphous oxides.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"2015 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140651603","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

Circuit complexity of quantum access models for encoding classical data 经典数据编码量子存取模型的电路复杂性

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-04-23 DOI: 10.1038/s41534-024-00835-8

Xiao-Ming Zhang, Xiao Yuan

{"title":"Circuit complexity of quantum access models for encoding classical data","authors":"Xiao-Ming Zhang, Xiao Yuan","doi":"10.1038/s41534-024-00835-8","DOIUrl":"https://doi.org/10.1038/s41534-024-00835-8","url":null,"abstract":"How to efficiently encode classical data is a fundamental task in quantum computing. While many existing works treat classical data encoding as a black box in oracle-based quantum algorithms, their explicit constructions are crucial for the efficiency of practical algorithm implementations. Here, we unveil the mystery of the classical data encoding black box and study the Clifford + T complexity in constructing several typical quantum access models. For general matrices (even including sparse ones), we prove that sparse-access input models and block-encoding both require nearly linear circuit complexities relative to the matrix dimension. We also give construction protocols achieving near-optimal gate complexities. On the other hand, the construction becomes efficient with respect to the data qubit when the matrix is a linear combination of polynomial terms of efficiently implementable unitaries. As a typical example, we propose improved block-encoding when these unitaries are Pauli strings. Our protocols are built upon improved quantum state preparation and a select oracle for Pauli strings, which hold independent values. Our access model constructions provide considerable flexibility, allowing for tunable ancillary qubit numbers and offering corresponding space-time trade-offs.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"117 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2024-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140639718","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

Quantum sensing of magnetic fields with molecular spins 利用分子自旋对磁场进行量子传感

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-04-23 DOI: 10.1038/s41534-024-00838-5

Claudio Bonizzoni, Alberto Ghirri, Fabio Santanni, Marco Affronte

引用次数: 0