npj Quantum Information最新文献_第5页

Scalable determination of multipartite entanglement in quantum networks 量子网络中多方位纠缠的可扩展测定

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-08-08 DOI: 10.1038/s41534-024-00867-0

Wei-Ting Kao, Chien-Ying Huang, Tung-Ju Tsai, Shih-Hsuan Chen, Sheng-Yan Sun, Yu-Cheng Li, Teh-Lu Liao, Chih-Sung Chuu, He Lu, Che-Ming Li

{"title":"Scalable determination of multipartite entanglement in quantum networks","authors":"Wei-Ting Kao, Chien-Ying Huang, Tung-Ju Tsai, Shih-Hsuan Chen, Sheng-Yan Sun, Yu-Cheng Li, Teh-Lu Liao, Chih-Sung Chuu, He Lu, Che-Ming Li","doi":"10.1038/s41534-024-00867-0","DOIUrl":"https://doi.org/10.1038/s41534-024-00867-0","url":null,"abstract":"Quantum networks comprised of entangled end nodes serve stronger than the classical correlation for unparalleled quantum internet applications. However, practical quantum networking is affected by noise, which at its worst, causes end nodes to be described by pre-existing classical data. In such untrusted networks, determining quantum network fidelity and genuine multi-node entanglement becomes crucial. Here, we show that determining quantum network fidelity and genuine N-node entanglement in an untrusted star network requires only N + 1 measurement settings. This method establishes a semi-trusted framework, allowing some nodes to relax their assumptions. Our network determination method is enabled by detecting genuine N-node Einstein-Podolsky-Rosen steerability. Experimentally, using spontaneous parametric down-conversion entanglement sources, we demonstrate the determinations of genuine 3-photon and 4-photon quantum networks and the false positives of the widely used entanglement witness, the fidelity criterion of 1/2. Our results provide a scalable method for the determination of multipartite entanglement in realistic quantum networks.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":null,"pages":null},"PeriodicalIF":7.6,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141904627","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

Information compression via hidden subgroup quantum autoencoders 通过隐藏子群量子自动编码器实现信息压缩

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-08-08 DOI: 10.1038/s41534-024-00865-2

Feiyang Liu, Kaiming Bian, Fei Meng, Wen Zhang, Oscar Dahlsten

{"title":"Information compression via hidden subgroup quantum autoencoders","authors":"Feiyang Liu, Kaiming Bian, Fei Meng, Wen Zhang, Oscar Dahlsten","doi":"10.1038/s41534-024-00865-2","DOIUrl":"https://doi.org/10.1038/s41534-024-00865-2","url":null,"abstract":"We design a quantum method for classical information compression that exploits the hidden subgroup quantum algorithm. We consider sequence data in a database with a priori unknown symmetries of the hidden subgroup type. We prove that data with a given group structure can be compressed with the same query complexity as the hidden subgroup problem, which is exponentially faster than the best-known classical algorithms. We moreover design a quantum algorithm that variationally finds the group structure and uses it to compress the data. There is an encoder and a decoder, along the paradigm of quantum autoencoders. After the training, the encoder outputs a compressed data string and a description of the hidden subgroup symmetry, from which the input data can be recovered by the decoder. In illustrative examples, our algorithm outperforms the classical autoencoder on the mean squared value of test data. This classical-quantum separation in information compression capability has thermodynamical significance: the free energy assigned by a quantum agent to a system can be much higher than that of a classical agent. Taken together, our results show that a possible application of quantum computers is to efficiently compress certain types of data that cannot be efficiently compressed by current methods using classical computers.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":null,"pages":null},"PeriodicalIF":7.6,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141909206","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

Fundamental causal bounds of quantum random access memories 量子随机存取存储器的基本因果界限

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-07-23 DOI: 10.1038/s41534-024-00848-3

Yunfei Wang, Yuri Alexeev, Liang Jiang, Frederic T. Chong, Junyu Liu

{"title":"Fundamental causal bounds of quantum random access memories","authors":"Yunfei Wang, Yuri Alexeev, Liang Jiang, Frederic T. Chong, Junyu Liu","doi":"10.1038/s41534-024-00848-3","DOIUrl":"https://doi.org/10.1038/s41534-024-00848-3","url":null,"abstract":"Our study evaluates the limitations and potentials of Quantum Random Access Memory (QRAM) within the principles of quantum physics and relativity. QRAM is crucial for advancing quantum algorithms in fields like linear algebra and machine learning, purported to efficiently manage large data sets with ({{{mathcal{O}}}}(log N)) circuit depth. However, its scalability is questioned when considering the relativistic constraints on qubits interacting locally. Utilizing relativistic quantum field theory and Lieb–Robinson bounds, we delve into the causality-based limits of QRAM. Our investigation introduces a feasible QRAM model in hybrid quantum acoustic systems, capable of supporting a significant number of logical qubits across different dimensions-up to ~107 in 1D, ~1015 to ~1020 in 2D, and ~1024 in 3D, within practical operation parameters. This analysis suggests that relativistic causality principles could universally influence quantum computing hardware, underscoring the need for innovative quantum memory solutions to navigate these foundational barriers, thereby enhancing future quantum computing endeavors in data science.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":null,"pages":null},"PeriodicalIF":7.6,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141755324","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

The silicon vacancy centers in SiC: determination of intrinsic spin dynamics for integrated quantum photonics 碳化硅中的硅空位中心：确定集成量子光子学的内在自旋动力学

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-07-23 DOI: 10.1038/s41534-024-00861-6

Di Liu, Florian Kaiser, Vladislav Bushmakin, Erik Hesselmeier, Timo Steidl, Takeshi Ohshima, Nguyen Tien Son, Jawad Ul-Hassan, Öney O. Soykal, Jörg Wrachtrup

{"title":"The silicon vacancy centers in SiC: determination of intrinsic spin dynamics for integrated quantum photonics","authors":"Di Liu, Florian Kaiser, Vladislav Bushmakin, Erik Hesselmeier, Timo Steidl, Takeshi Ohshima, Nguyen Tien Son, Jawad Ul-Hassan, Öney O. Soykal, Jörg Wrachtrup","doi":"10.1038/s41534-024-00861-6","DOIUrl":"https://doi.org/10.1038/s41534-024-00861-6","url":null,"abstract":"The negatively charged silicon vacancy center (({{rm{V}}}_{{rm{Si}}}^{-})) in silicon carbide (SiC) is an emerging color center for quantum technology covering quantum sensing, communication, and computing. Yet, limited information currently available on the internal spin-optical dynamics of these color centers prevents us from achieving the optimal operation conditions and reaching the maximum performance especially when integrated within quantum photonics. Here, we establish all the relevant intrinsic spin dynamics of the ({{rm{V}}}_{{rm{Si}}}^{-}) center at cubic lattice site (V2) in 4H-SiC by an in-depth electronic fine structure modeling including the intersystem-crossing and deshelving mechanisms. With carefully designed spin-dependent measurements, we obtain all the previously unknown spin-selective radiative and non-radiative decay rates. To showcase the relevance of our work for integrated quantum photonics, we use the obtained rates to propose a realistic implementation of time-bin entangled multi-photon GHZ and cluster state generation. We find that up to three-photon GHZ or cluster states are readily within reach using the existing nanophotonic cavity technology.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":null,"pages":null},"PeriodicalIF":7.6,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141755325","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

Low charge noise quantum dots with industrial CMOS manufacturing 利用工业 CMOS 制造低电荷噪声量子点

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-07-19 DOI: 10.1038/s41534-024-00864-3

A. Elsayed, M. M. K. Shehata, C. Godfrin, S. Kubicek, S. Massar, Y. Canvel, J. Jussot, G. Simion, M. Mongillo, D. Wan, B. Govoreanu, I. P. Radu, R. Li, P. Van Dorpe, K. De Greve

{"title":"Low charge noise quantum dots with industrial CMOS manufacturing","authors":"A. Elsayed, M. M. K. Shehata, C. Godfrin, S. Kubicek, S. Massar, Y. Canvel, J. Jussot, G. Simion, M. Mongillo, D. Wan, B. Govoreanu, I. P. Radu, R. Li, P. Van Dorpe, K. De Greve","doi":"10.1038/s41534-024-00864-3","DOIUrl":"https://doi.org/10.1038/s41534-024-00864-3","url":null,"abstract":"Silicon spin qubits are promising candidates for scalable quantum computers, due to their coherence and compatibility with CMOS technology. Advanced industrial processes ensure wafer-scale uniformity and high device yield, but traditional transistor processes cannot be directly transferred to qubit structures. To leverage the micro-electronics industry expertise, we customize a 300 mm wafer fabrication line for silicon MOS qubit integration. With careful optimization of the gate stack, we report uniform quantum dot operation at the Si/SiO2 interface at mK temperature. We measure a record-low average noise with a value of 0.61 ({rm{mu }}{rm{eVH}}{{rm{z}}}^{-0.5}) at 1 Hz and even below 0.1 ({rm{mu }}{rm{eVH}}{{rm{z}}}^{-0.5}) for some operating conditions. Statistical analysis of the charge noise measurements show that the noise source can be described by a two-level fluctuator model. This reproducible low noise level, in combination with uniform operation of our quantum dots, marks CMOS manufactured spin qubits as a mature platform towards scalable high-fidelity qubits.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":null,"pages":null},"PeriodicalIF":7.6,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141730697","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

Charge-parity switching effects and optimisation of transmon-qubit design parameters 电荷奇偶性开关效应与跨子-量子比特设计参数的优化

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-07-15 DOI: 10.1038/s41534-024-00860-7

Miha Papič, Jani Tuorila, Adrian Auer, Inés de Vega, Amin Hosseinkhani

{"title":"Charge-parity switching effects and optimisation of transmon-qubit design parameters","authors":"Miha Papič, Jani Tuorila, Adrian Auer, Inés de Vega, Amin Hosseinkhani","doi":"10.1038/s41534-024-00860-7","DOIUrl":"https://doi.org/10.1038/s41534-024-00860-7","url":null,"abstract":"Enhancing the performance of noisy quantum processors requires improving our understanding of error mechanisms and the ways to overcome them. A judicious selection of qubit design parameters plays a pivotal role in improving the performance of quantum processors. In this study, we identify optimal ranges for qubit design parameters, grounded in comprehensive noise modeling. To this end, we also analyze the effect of a charge-parity switch caused by quasiparticles on a two-qubit gate. Due to the utilization of the second excited state of a transmon, where the charge dispersion is significantly larger, a charge-parity switch will affect the conditional phase of the two-qubit gate. We derive an analytical expression for the infidelity of a diabatic controlled-Z gate and see effects of similar magnitude in adiabatic controlled-phase gates in the tunable coupler architecture. Moreover, we show that the effect of a charge-parity switch can be the dominant quasiparticle-related error source of a two-qubit gate. We also demonstrate that charge-parity switches induce a residual longitudinal interaction between qubits in a tunable-coupler circuit. Furthermore, we introduce a performance metric for quantum circuit execution, encompassing the fidelity and number of single- and two-qubit gates in an algorithm, as well as the state preparation fidelity. This comprehensive metric, coupled with a detailed noise model, enables us to determine an optimal range for the qubit design parameters, as confirmed by numerical simulation. Our systematic analysis offers insights and serves as a guiding framework for the development of the next generation of transmon-based quantum processors.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":null,"pages":null},"PeriodicalIF":7.6,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141625104","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

Contextual quantum metrology 语境量子计量学

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-07-04 DOI: 10.1038/s41534-024-00862-5

Jeongwoo Jae, Jiwon Lee, M. S. Kim, Kwang-Geol Lee, Jinhyoung Lee

引用次数: 0

Shortcut to multipartite entanglement generation: A graph approach to boson subtractions 多方纠缠生成的捷径：玻色子减法的图方法

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-07-03 DOI: 10.1038/s41534-024-00845-6

Seungbeom Chin, Yong-Su Kim, Marcin Karczewski

引用次数: 0

Approximate encoding of quantum states using shallow circuits 利用浅层电路对量子态进行近似编码

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-07-02 DOI: 10.1038/s41534-024-00858-1

Matan Ben-Dov, David Shnaiderov, Adi Makmal, Emanuele G. Dalla Torre

引用次数: 0

Experimental error suppression in Cross-Resonance gates via multi-derivative pulse shaping 通过多衍生脉冲整形抑制交叉谐振门的实验误差

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2024-07-02 DOI: 10.1038/s41534-024-00863-4

Boxi Li, Tommaso Calarco, Felix Motzoi

{"title":"Experimental error suppression in Cross-Resonance gates via multi-derivative pulse shaping","authors":"Boxi Li, Tommaso Calarco, Felix Motzoi","doi":"10.1038/s41534-024-00863-4","DOIUrl":"https://doi.org/10.1038/s41534-024-00863-4","url":null,"abstract":"While quantum circuits are reaching impressive widths in the hundreds of qubits, their depths have not been able to keep pace. In particular, cloud computing gates on multi-qubit, fixed-frequency superconducting chips continue to hover around the 1% error range, contrasting with the progress seen on carefully designed two-qubit chips, where error rates have been pushed towards 0.1%. Despite the strong impetus and a plethora of research, experimental demonstration of error suppression on these multi-qubit devices remains challenging, primarily due to the wide distribution of qubit parameters and the demanding calibration process required for advanced control methods. Here, we achieve this goal, using a simple control method based on multi-derivative, multi-constraint pulse shaping, which acts simultaneously against multiple error sources. Our approach establishes a two to fourfold improvement on the default calibration scheme, demonstrated on four qubits on the IBM Quantum Platform with limited and intermittent access, enabling these large-scale fixed-frequency systems to fully take advantage of their superior coherence times. The achieved CNOT fidelities of 99.7(1)% on those publically available qubits come from both coherent control error suppression and accelerated gate time.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":null,"pages":null},"PeriodicalIF":7.6,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141489604","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