npj Quantum Information最新文献_第6页

Experimental causal inference from measurements alone in the presence of spatial and temporal quantum correlations 在存在空间和时间量子相关性的情况下，仅从测量得出的实验因果推断

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2026-08-10 DOI: 10.1038/s41534-026-01337-5

Hongfeng Liu, Xiangjing Liu, Qian Chen, Yixian Qiu, Vlatko Vedral, Xinfang Nie, Oscar Dahlsten, Dawei Lu

引用次数: 0

Digital quantum simulation of many-body localization crossover in a disordered kicked Ising model 无序踢Ising模型中多体定位交叉的数字量子模拟

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2026-08-07 DOI: 10.1038/s41534-026-01342-8

Tomoya Hayata, Kazuya Shinjo, Kazuhiro Seki, Seiji Yunoki

{"title":"Digital quantum simulation of many-body localization crossover in a disordered kicked Ising model","authors":"Tomoya Hayata, Kazuya Shinjo, Kazuhiro Seki, Seiji Yunoki","doi":"10.1038/s41534-026-01342-8","DOIUrl":"https://doi.org/10.1038/s41534-026-01342-8","url":null,"abstract":"Simulating nonequilibrium dynamics of quantum many-body systems is one of the most promising applications of quantum computers. However, a faithful digital quantum simulation of the Hamiltonian evolution is very challenging in the present noisy quantum devices. Instead, nonequilibrium dynamics under the Floquet evolution realized by the Trotter decomposition of the Hamiltonian evolution with a large Trotter step size is considered to be a suitable problem for simulating in the present or near-term quantum devices. In this work, we study the many-body localization crossover as such a nonequilibrium problem in the disordered Floquet many-body systems. As a demonstration, we simulate the many-body localization crossover in a disordered kicked Ising model on a heavy-hex lattice using 60 qubits from 156 qubits available in the IBM Heron r2 superconducting qubit device named ibm_fez. We compute out-of-time-ordered correlators as an indicator of the many-body localization crossover. From the late-time behavior of out-of-time-ordered correlators, we locate the quantum chaotic and many-body localized regimes as a function of the disorder strength. The validity of our results is supported by comparisons with classical tensor-network simulations and by consistency between two independent error-mitigation methods, namely, operator renormalization and zero-noise extrapolation.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"199 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2026-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148693405","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 secret sharing in a triangular superconducting quantum network 三角超导量子网络中的量子秘密共享

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2026-08-06 DOI: 10.1038/s41534-026-01341-9

Haoxiong Yan, Allen Zang, Joel Grebel, Xuntao Wu, Ming-Han Chou, Gustav Andersson, Christopher R. Conner, Yash J. Joshi, Shiheng Li, Jacob M. Miller, Rhys G. Povey, Hong Qiao, Eric Chitambar, Andrew N. Cleland

引用次数: 0

Singularity-free dynamical invariants-based quantum control 基于无奇点动态不变量的量子控制

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2026-08-05 DOI: 10.1038/s41534-026-01343-7

Ritik Sareen, Akram Youssry, Alberto Peruzzo

{"title":"Singularity-free dynamical invariants-based quantum control","authors":"Ritik Sareen, Akram Youssry, Alberto Peruzzo","doi":"10.1038/s41534-026-01343-7","DOIUrl":"https://doi.org/10.1038/s41534-026-01343-7","url":null,"abstract":"State preparation is a cornerstone of quantum technologies, underpinning applications in computation, communication, and sensing. Its importance becomes even more pronounced in non-Markovian open quantum systems, where environmental memory and model uncertainties pose significant challenges to achieving high-fidelity control. Invariant-based inverse engineering provides a principled framework for synthesizing analytic control fields, yet existing parameterizations often lead to experimentally infeasible, singular pulses and are limited to simplified noise models such as those of Lindblad form. Here, we introduce a generalized invariant-based protocol for finite-dimensional state preparation under arbitrary noise conditions. We transform the finite-dimensional control problem into the equivalent problem for a single-qubit, by restricting the dynamics to a designed SU(2) subspace. The control protocol then proceeds in two-stages: first, we construct a family of bounded pulses that achieve perfect state preparation in a closed system; second, we identify the optimal member of this family that minimizes the effect of noise. The framework accommodates both (i) characterized noise, enabling noise-aware control synthesis, and (ii) uncharacterized noise, where a noise-agnostic variant preserves robustness without requiring a master-equation description. Numerical simulations demonstrate high-fidelity state preparation across diverse targets while producing smooth, hardware-feasible control fields. This singularity-free framework extends invariant-based control to realistic open-system regimes, providing a versatile route toward robust quantum state engineering on NISQ hardware and other platforms exhibiting non-Markovian dynamics.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"35 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148693486","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

A folded surface code architecture for 2D quantum hardware 二维量子硬件的折叠面代码结构

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2026-08-05 DOI: 10.1038/s41534-026-01344-6

Zhu Sun, Zhenyu Cai

{"title":"A folded surface code architecture for 2D quantum hardware","authors":"Zhu Sun, Zhenyu Cai","doi":"10.1038/s41534-026-01344-6","DOIUrl":"https://doi.org/10.1038/s41534-026-01344-6","url":null,"abstract":"Qubit shuttling has become an indispensable ingredient for scaling leading quantum computing platforms, including semiconductor spin, neutral-atom, and trapped-ion qubits, enabling both crosstalk reduction and tighter integration of control hardware. ref. 1 proposed a scalable architecture that employs short-range shuttling to realize effective three-dimensional connectivity on a strictly two-dimensional device. Building on recent advances in quantum error correction, we show that this architecture enables the native implementation of folded surface codes on 2D hardware, reducing the runtime of all single-qubit logical Clifford gates and logical CNOTs within subsets of qubits from ({mathcal{O}}(d)) in conventional surface code lattice surgery to constant time. We present explicit protocols for these operations and demonstrate that access to a transversal S gate reduces the spacetime volume of 8T-to-CCZ magic-state distillation by more than an order of magnitude compared with standard 2D lattice surgery approaches. Finally, we introduce a new “virtual-stack” layout that more efficiently exploits the quasi-three-dimensional structure of the architecture, enabling efficient multilayer routing on these two-dimensional devices.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"5 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148693516","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

Merging-based quantum repeater 基于合并的量子中继器

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2026-08-05 DOI: 10.1038/s41534-026-01340-w

Maria Flors Mor-Ruiz, Jorge Miguel-Ramiro, Julius Wallnöfer, Tim Coopmans, Wolfgang Dür

引用次数: 0

A unitary encoder for surface codes 表面码的统一编码器

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2026-08-04 DOI: 10.1038/s41534-026-01322-y

Pei-Kai Tsai, Shruti Puri

{"title":"A unitary encoder for surface codes","authors":"Pei-Kai Tsai, Shruti Puri","doi":"10.1038/s41534-026-01322-y","DOIUrl":"https://doi.org/10.1038/s41534-026-01322-y","url":null,"abstract":"The surface code is a promising candidate for fault-tolerant quantum computation and has been implemented in many quantum hardware platforms. In this work, we propose a new non-local unitary circuit to encode surface code states based on a code conversion between rotated and regular surface codes, which halves the circuit depth of the fastest unitary encoder known previously. While the unitary encoders can be used to increase the code size, the fault-distance remains fixed. Nonetheless, they can be used for space-time efficient preparation of eigenstates of the logical operators that cannot be easily accessed transversally such as the Pauli Y-eignestate and Clifford eigenstates. It may be expected that error propagation in the non-local circuit will make decoding more challenging compared to local ones. However, we find that conventional matching decoders can still be effectively used. Furthermore, we perform numerical simulations to benchmark the performance of our encoder against a local unitary encoder and the conventional stabilizer-measurement based approach for preparing the Pauli Y-eigenstate. We find that our encoder can outperform other approaches in certain experimentally relevant noise regimes. Therefore, our encoder provides practical advantage in platforms where non-local interactions are available such as neutral atoms and trapped ions.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"2 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148693427","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

Noise-assisted feedback control of open quantum systems for ground state properties 开放量子系统基态特性的噪声辅助反馈控制

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2026-08-03 DOI: 10.1038/s41534-026-01319-7

Kasturi Ranjan Swain, Rajesh K. Malla, Adolfo del Campo

{"title":"Noise-assisted feedback control of open quantum systems for ground state properties","authors":"Kasturi Ranjan Swain, Rajesh K. Malla, Adolfo del Campo","doi":"10.1038/s41534-026-01319-7","DOIUrl":"https://doi.org/10.1038/s41534-026-01319-7","url":null,"abstract":"Intrinsic noise in pre-fault-tolerant quantum devices poses a major challenge to the reliable realization of unitary dynamics in quantum algorithms and simulations. To address this, we present a method for simulating open quantum system dynamics on a quantum computer, including negative dissipation rates in the Gorini–Kossakowski–Sudarshan–Lindblad (GKSL) master equation. Our approach lies beyond the standard Markovian approximation, enabling the controlled study of non-Markovian processes within a quantum simulation framework. Using this method, we develop a quantum algorithm for calculating ground-state properties that exploits feedback-controlled, noise-assisted dynamics. In this scheme, Lyapunov-based feedback steers the system toward a target virtual state under engineered noise conditions. While noisy simulations typically fail to converge and degrade in performance as noise accumulates over time, our method exhibits improved convergence, albeit with an increased exponential sampling overhead. This framework offers a promising strategy for harnessing current quantum hardware and advancing robust control protocols based on open-system dynamics.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"30 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2026-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148693428","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

Asynchronous multi-photon interference for quantum networks 量子网络中的异步多光子干涉

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2026-07-30 DOI: 10.1038/s41534-026-01333-9

Baghdasar Baghdasaryan, Karen Lozano-Méndez, Markus Leipe, Meritxell Cabrejo-Ponce, Sabine Häussler, Kaushik Joarder, Tim Gühring, Stephan Fritzsche, Thorsten A. Goebel, Ria G. Krämer, Stefan Nolte, Carlos Andres Melo Luna, Yoshiaki Tsujimoto, Fabian Steinlechner

{"title":"Asynchronous multi-photon interference for quantum networks","authors":"Baghdasar Baghdasaryan, Karen Lozano-Méndez, Markus Leipe, Meritxell Cabrejo-Ponce, Sabine Häussler, Kaushik Joarder, Tim Gühring, Stephan Fritzsche, Thorsten A. Goebel, Ria G. Krämer, Stefan Nolte, Carlos Andres Melo Luna, Yoshiaki Tsujimoto, Fabian Steinlechner","doi":"10.1038/s41534-026-01333-9","DOIUrl":"https://doi.org/10.1038/s41534-026-01333-9","url":null,"abstract":"Abstract: Advanced quantum communication protocols require high-visibility quantum interference between photons generated at distant nodes, which places stringent demands on optical synchronization. Conventionally, synchronization of optical wave packets relies on pulsed sources and precise optical path stabilization. An alternative approach employs continuous-wave (CW) photon-pair sources, where temporal indistinguishability of photons is enforced by post-selecting detection events within a coincidence window τw shorter than the photon coherence time Tc. Despite its conceptual simplicity, the quantitative relation between relevant time scales, achievable interference visibility, and usable multi-photon rates has remained unclear. Here, we develop in detail and experimentally validate a theoretical framework that quantitatively describes time-resolved multi-photon interference in the CW regime. We explicitly incorporate detector timing jitter, photon coherence time, and temporal post-selection. The model is verified using four-photon Hong-Ou-Mandel interference measurements. Based on this validated framework, we determine the coincidence window that maximizes usable four-photon rates for a target interference visibility. Finally, we compare CW and pulsed spontaneous parametric down-conversion sources under equivalent indistinguishability constraints and show that CW operation can achieve comparable rates while relaxing optical synchronization requirements.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"13 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2026-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148612786","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

Advantage of quantum machine learning from general computational advantages 量子机器学习的优势来自于一般计算的优势

IF 7.6 1区物理与天体物理

npj Quantum Information Pub Date : 2026-07-28 DOI: 10.1038/s41534-026-01279-y

Hayata Yamasaki, Natsuto Isogai, Mio Murao

{"title":"Advantage of quantum machine learning from general computational advantages","authors":"Hayata Yamasaki, Natsuto Isogai, Mio Murao","doi":"10.1038/s41534-026-01279-y","DOIUrl":"https://doi.org/10.1038/s41534-026-01279-y","url":null,"abstract":"An overarching milestone of quantum machine learning (QML) is to demonstrate the advantage of QML over all possible classical learning methods in accelerating a common type of learning task, as represented by supervised learning from classical data. However, the provable advantages of QML in supervised learning have been known so far only for the learning tasks designed for using the advantage of specific quantum algorithms, i.e., Shor’s algorithms. Here, we explicitly construct an unprecedentedly broader family of supervised learning tasks with classical data to offer the provable advantage of QML based on general quantum computational advantages, progressing beyond Shor’s algorithms. Our learning task is feasibly achievable by executing a general class of functions that can be computed efficiently in polynomial time for a large fraction of inputs by arbitrary quantum algorithms, but not by any classical algorithm. We prove the hardness of achieving this learning task for any possible polynomial-time classical learning method. We also clarify protocols for preparing the classical data to demonstrate this learning task in experiments. These results provide a way to exploit a variety of quantum advantages in computing functions for the realization of provably advantageous QML.","PeriodicalId":19212,"journal":{"name":"npj Quantum Information","volume":"74 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2026-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148612781","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