IEEE Transactions on Quantum Engineering最新文献

{"title":"Field Demonstration of a Passive Phase and Polarization Stabilization Architecture for Sagnac Twin-Field QKD","authors":"Martin Clason;Christiano M. S. do Nascimento;Felipe Calliari;Joakim Argillander;Guilherme B. Xavier;Guilherme P. Temporão","doi":"10.1109/TQE.2026.3728701","DOIUrl":"https://doi.org/10.1109/TQE.2026.3728701","url":null,"abstract":"Twin-field quantum key distribution (TF-QKD) relies on first-order interference between coherent optical fields combined at an intermediate station, which requires simultaneous phase and polarization stabilization. We present a Sagnac-like interferometric architecture arranged in a hybrid star–bus network topology that enables any-to-any connectivity while providing passive stabilization of phase and polarization fluctuations for multiple wavelengths. The proposed configuration, which integrates Faraday mirrors in a Plug-and-Play scheme, operates without active feedback. Experimental results in a 110 km-long installed fiber link between the cities of Linköping and Nyköping, Sweden, show 99.2% visibility maintained over 14 h of continuous operation with 0.33% standard deviation. The main limitation of this configuration—Rayleigh backscattering—was circumvented by time filtering.","PeriodicalId":100644,"journal":{"name":"IEEE Transactions on Quantum Engineering","volume":"7 ","pages":"1-12"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11669995","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149249535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Satellite Microwave Detection via Cavity-Coupled Rydberg Atomic Receiver","authors":"Mingwei Lei;Meng Shi","doi":"10.1109/TQE.2026.3690617","DOIUrl":"https://doi.org/10.1109/TQE.2026.3690617","url":null,"abstract":"Due to the small interaction region between Rydberg atoms and the microwave (MW) field, it is difficult to detect weak satellite signals using free-space-coupled atomic receivers. In this work, we introduce a cavity-coupled Rydberg atomic receiver to enhance the MW field and combine it with a passive antenna to detect C-band satellite signals. Using MW-atom enhanced coupling, the minimum detectable power of incident MW is reduced to −128 dBm, and the corresponding sensitivity sensing by atoms is estimated as 21 nV/cm/Hz^1/2 at a frequency of 3.80 GHz. Furthermore, we also show the effectiveness of this scheme by capturing the beacon signal from a geostationary satellite, without the need for low-noise amplifiers often used in conventional detection. Besides, modulated satellite signals are received with a signal-to-noise ratio of 8 dB with a measurement bandwidth of 10 Hz. Our results demonstrate an advancement in facilitating satellite communications using cavity-coupled Rydberg-atom receivers.","PeriodicalId":100644,"journal":{"name":"IEEE Transactions on Quantum Engineering","volume":"7 ","pages":"1-6"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11508155","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148171750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Robust Quantum Walk Search on Complete Multipartite Graph With Multiple Marked Vertices","authors":"Ningxiang Chen;Meng Li;Xiaoming Sun","doi":"10.1109/TQE.2026.3679863","DOIUrl":"https://doi.org/10.1109/TQE.2026.3679863","url":null,"abstract":"Quantum walks are a potent technique for building quantum algorithms. This article examines the quantum walk search algorithm on complete multipartite graphs with multiple marked vertices, which has not been explored before. We employ the coined quantum walk model and achieve quadratic speedup with a constant probability of finding a marked vertex in two specific cases of complete multipartite graphs. Furthermore, we investigate the robust quantum walk of two cases and demonstrate that even with an unknown number of marked vertices, it is still possible to achieve a quadratic speedup compared to classical algorithms and the success probability oscillates within a small range close to 1. To establish this conclusion, we employ approximation and reduction methods to conduct theoretical analysis and proofs, and provide an intuitive demonstration through numerical simulations. This work addresses the overcooking problem in quantum walk search algorithms on some complete multipartite graphs and may offer insights for robust quantum search on broader graph structures. Finally, we design a circuit for the algorithm that future researchers can use to conduct experiments.","PeriodicalId":100644,"journal":{"name":"IEEE Transactions on Quantum Engineering","volume":"7 ","pages":"1-14"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11466472","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148479308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Routing in Nonisotonic Quantum Networks","authors":"Maxwell Tang;Garrett Hinkley;Kenneth Goodenough;Stefan Krastanov;Guus Avis","doi":"10.1109/TQE.2026.3703366","DOIUrl":"https://doi.org/10.1109/TQE.2026.3703366","url":null,"abstract":"Optimal routing in quantum-repeater networks requires finding the best path that connects a pair of end nodes. Most previous work on routing in quantum networks assumes utility functions that are isotonic, meaning that the ordering of two paths does not change when extending both with the same edge. However, we show that utility functions that take into account both the rate and quality of the entanglement generation (e.g., the secret-key rate) are often nonisotonic. This makes pathfinding difficult as classical algorithms such as Dijkstra’s become unsuitable, with the state of the art for quantum networks being an exhaustive search over all possible paths. In this work, we present improved algorithms. First, we present two best-first-search algorithms that use destination-aware merit functions for faster convergence. One of these provably finds the best path, while the other uses heuristics to achieve an effectively sublinear scaling of the query count in the network size while in practice always finding a close-to-optimal path. Second, we present metaheuristic algorithms (simulated annealing and a genetic algorithm) that enable tuning a tradeoff between path quality and computational overhead. While we focus on swap-as-soon-as-possible quantum repeaters for concreteness, our algorithms are readily generalized to different repeater schemes and models.","PeriodicalId":100644,"journal":{"name":"IEEE Transactions on Quantum Engineering","volume":"7 ","pages":"4101522-4101522"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11563660","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148481232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Encoder Circuit Optimization for Nonbinary Quantum Error Correction Codes in Prime Dimensions: An Algorithmic Framework","authors":"Aditya Sodhani;Keshab K. Parhi","doi":"10.1109/TQE.2026.3669054","DOIUrl":"https://doi.org/10.1109/TQE.2026.3669054","url":null,"abstract":"Quantum computers are a revolutionary class of computational platforms with applications in combinatorial and global optimization, machine learning, and other domains involving computationally hard problems. While these machines typically operate on qubits—quantum information elements that can occupy superpositions of the basis <inline-formula><tex-math>$|0rangle$</tex-math></inline-formula> and <inline-formula><tex-math>$|1rangle$</tex-math></inline-formula> states—recent advances have demonstrated the practical implementation of higher dimensional quantum systems (qudits) across various hardware platforms. In these hardware realizations, the higher order states are less stable, and thus remain coherent for a shorter duration than the basis <inline-formula><tex-math>$|0rangle$</tex-math></inline-formula> and <inline-formula><tex-math>$|1rangle$</tex-math></inline-formula> states. Moreover, formal methods for designing efficient encoder circuits for these systems remain underexplored. This limitation motivates the development of efficient circuit techniques for qudit systems (<italic>d</i>-level quantum systems). Previous works have typically established generating gate sets for higher dimensional codes by generalizing the methods used for qubits. In this work, we introduce a systematic framework for optimizing encoder circuits for prime-dimension stabilizer codes. This framework is based on novel generating gate sets whose elements map directly to efficient Clifford gate sequences. We demonstrate the effectiveness of this method on key codes, achieving a 13% –44% reduction in encoder circuit gate count for the qutrit (<italic>d</i> = 3) <inline-formula><tex-math>$[[9,5,3]]_{3}$</tex-math></inline-formula>, <inline-formula><tex-math>$[[5,1,3]]_{3}$</tex-math></inline-formula>, and <inline-formula><tex-math>$[[7,1,3]]_{3}$</tex-math></inline-formula> codes, and a 9% –21% reduction for the ququint (<italic>d</i> = 5) <inline-formula><tex-math>$[[10,6,3]]_{5}$</tex-math></inline-formula> code when compared to prior work. We also achieved circuit depth reductions up to 42%.","PeriodicalId":100644,"journal":{"name":"IEEE Transactions on Quantum Engineering","volume":"7 ","pages":"1-15"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11417923","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148480373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synchronizable Hybrid Subsystem Codes","authors":"Theerapat Tansuwannont;Andrew Nemec","doi":"10.1109/TQE.2026.3673092","DOIUrl":"https://doi.org/10.1109/TQE.2026.3673092","url":null,"abstract":"Quantum synchronizable codes are quantum error correcting codes that can correct not only Pauli errors but also errors in block synchronization. The code can be constructed from two classical cyclic codes <inline-formula><tex-math>${mathcal {C}}$</tex-math></inline-formula>, <inline-formula><tex-math>${mathcal {D}}$</tex-math></inline-formula> satisfying <inline-formula><tex-math>${mathcal {C}}^{perp } subset {mathcal {C}} subset {mathcal {D}}$</tex-math></inline-formula> through the Calderbank–Shor–Steane (CSS) code construction. In this work, we establish connections between quantum synchronizable codes, subsystem codes, and hybrid quantum–classical codes constructed from the same pair of classical cyclic codes. We also propose a method to construct a synchronizable hybrid subsystem code, which can correct both Pauli and synchronization errors, is resilient to gauge errors by virtue of the subsystem structure, and can transmit both classical and quantum information, all at the same time. The tradeoffs between the number of synchronization errors that the code can correct, the number of gauge qubits, and the number of logical classical bits of the code are also established. In addition, we propose general methods to construct hybrid and hybrid subsystem codes of CSS type from classical codes, which cover relevant codes from our main construction.","PeriodicalId":100644,"journal":{"name":"IEEE Transactions on Quantum Engineering","volume":"7 ","pages":"2100730-2100730"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11430722","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148480689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Encrypted-State Quantum Compilation Scheme Based on Quantum Circuit Obfuscation for Quantum Cloud Platforms","authors":"Chenyi Zhang;Tao Shang;Xueyi Guo;Yuanjing Zhang","doi":"10.1109/TQE.2026.3659096","DOIUrl":"https://doi.org/10.1109/TQE.2026.3659096","url":null,"abstract":"With the rapid advancement of quantum computing, quantum compilation has become a crucial layer connecting high-level algorithms with physical hardware. In quantum cloud computing, compilation is performed on the cloud platforms, which expose user circuits to potential risks, such as structural leakage and output predictability. To address these issues, we propose the encrypted-state quantum compilation scheme based on quantum circuit obfuscation (ECQCO), the first secure compilation scheme tailored for the co-location of compilers and quantum hardware for quantum cloud platforms. It applies quantum homomorphic encryption to conceal output states and instantiates a structure obfuscation mechanism based on quantum indistinguishability obfuscation, effectively protecting both functionality and topology of the circuit. In addition, an adaptive decoupling obfuscation algorithm is designed to suppress potential idle errors while inserting pulse operations. The proposed scheme achieves information-theoretic security and guarantees computational indistinguishability under the quantum random oracle. Experimental results on benchmark datasets demonstrate that ECQCO achieves a total variation distance of up to 0.7 and a normalized graph edit distance of 0.88, enhancing compilation-stage security. Moreover, it introduces only a slight increase in circuit depth, while keeping the average fidelity change within 1.1%, thus achieving a practical balance between security and efficiency.","PeriodicalId":100644,"journal":{"name":"IEEE Transactions on Quantum Engineering","volume":"7 ","pages":"1-18"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11367741","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148482233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"RuleSet Generation Framework for Application Layer Integration in Quantum Internet","authors":"Rei Kawano;Shin Nishio;Hideaki Kawaguchi;Shota Nagayama;Takahiko Satoh","doi":"10.1109/TQE.2026.3729244","DOIUrl":"https://doi.org/10.1109/TQE.2026.3729244","url":null,"abstract":"Layered architectures for the Quantum Internet have been proposed, inspired by the architecture of the classical Internet, which has demonstrated high maintainability even in large-scale systems. While lower layers in the Quantum Internet, such as entanglement generation and distribution, have been extensively studied, the application layer—responsible for translating user requests into executable quantum-network operations—remains largely unexplored. A significant challenge is the translation of application-level requests into concrete instructions executable at lower layers. In this work, we introduce a RuleSet-based framework that explicitly incorporates the application layer into the layered architecture of the Quantum Internet. Our framework builds on a RuleSet-based protocol, clarifying communication procedures, organizing application request information, and introducing new rules for application execution by embedding application specifications into RuleSets. To evaluate its feasibility, we constructed state machines from the generated RuleSets and, through simulation, examined the behavior of the proposed method under multiapplication resource constraints. This approach enables a transparent integration from the application layer down to the physical layer, thereby lowering the barriers to deploying new applications on the Quantum Internet.","PeriodicalId":100644,"journal":{"name":"IEEE Transactions on Quantum Engineering","volume":"7 ","pages":"4102216-4102216"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11673064","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149133420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficiently Architecting VQAs: Expressibility–Trainability–Resources Pareto-Optimality","authors":"Rodrigo Martinez Sanz;Andreu Anglès-Castillo;Eduard Alarcón;Carmen G. Almudéver","doi":"10.1109/TQE.2026.3721256","DOIUrl":"https://doi.org/10.1109/TQE.2026.3721256","url":null,"abstract":"Ansatz selection is a key factor in the performance of variational quantum algorithms. While much of the state of the art still relies on heuristic choices, an inadequate circuit structure can compromise both the expressive power and the trainability of the resulting model. Recent results have also established theoretical connections between expressibility and the onset of barren plateaus, highlighting the need for systematic criteria for ansatz selection. In this work, the ansatz is treated as a design feature to be optimized rather than a fixed block, and a design space exploration is performed over a diverse set of parameterized quantum circuits (PQCs), considering the transverse-field Ising, Heisenberg, and Local-<inline-formula><tex-math>$X$</tex-math></inline-formula> Hamiltonians as representative benchmarks. Three complementary metrics—expressibility, trainability, and resource cost—are evaluated and used to analyze the tradeoffs that emerge across different PQCs. Beyond identifying Pareto-optimal candidates within the evaluated design space, this multiobjective perspective helps clarify the interplay between these metrics and contributes quantitative evidence toward understanding the expressibility–trainability tension in variational circuits.","PeriodicalId":100644,"journal":{"name":"IEEE Transactions on Quantum Engineering","volume":"7 ","pages":"3104517-3104517"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11663524","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148925330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Information-Theoretic Analysis of Bayesian Quantum State Search","authors":"Zhelun Li;Koji Terashi","doi":"10.1109/TQE.2026.3660364","DOIUrl":"https://doi.org/10.1109/TQE.2026.3660364","url":null,"abstract":"We present an information-theoretic approach to quantum state classification based on sequential Bayesian inference. In each measurement step, the algorithm updates a probability distribution over candidate states by applying Bayes' rule to the observed outcome. For each measurement shot on an unknown quantum state, the algorithm selects the observable with the highest expected information gain, continuing until convergence. We demonstrate using the simulations that this algorithm effectively identifies quantum states sampled from the Haar-random distribution. However, despite not relying on circuit-based quantum neural networks, the algorithm still encounters challenges akin to the barren plateau problem. In the leading order, we show that the information gain is proportional to the variance of the observable's expectation values over candidate states. As the system size increases, the variance and consequently the information gain are exponentially suppressed, which poses significant challenges for classifying general Haar-random quantum states. Finally, we apply the Bayesian search algorithm to classify the ground states of various Hamiltonians using physically motivated observables. On both simulators and quantum computers, the Bayesian search algorithm yields better performances when compared to methods that are not information-optimized. This indicates that the measurement of physically motivated observables can significantly improve the classification performance, guiding toward the future direction of this approach.","PeriodicalId":100644,"journal":{"name":"IEEE Transactions on Quantum Engineering","volume":"7 ","pages":"1-12"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11371445","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147557826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}