Quantum Information Processing最新文献

{"title":"Quantum codes from constacyclic codes over finite non-chain rings","authors":"Yongsheng Tang,&nbsp;Heqian Xu,&nbsp;Ting Yao,&nbsp;Xiaoshan Kai","doi":"10.1007/s11128-026-05334-7","DOIUrl":"10.1007/s11128-026-05334-7","url":null,"abstract":"<div><p>Let <i>R</i> be finite non-chain rings <span>(mathbb {F}_{q^{2m}}+{u}mathbb {F}_{q^{2m}})</span>, where <span>(mathbb {F}_{q^{2m}})</span> is a finite field with <span>(q^{2m})</span> elements, <i>q</i> is an odd prime power, <i>m</i> is a positive integer, <i>u</i> is an indeterminate with <span>({u}^{2}=1.)</span> In this paper, we firstly define a class of Gray maps, which changes Hermitian dual-containing property of linear codes over <i>R</i> into the Hermitian dual-containing property of linear codes over <span>(mathbb {F}_{q^{2m}})</span>. Applying Hermitian construction, a class of <span>(q^{m})</span>-ary quantum codes are obtained from Hermitian constacyclic dual-containing codes over <i>R</i>. Moreover, a family of <i>q</i>-ary primitive quantum BCH codes are determined via the Hermitian construction from the subfield subcodes of Gray images of Hermitian dual-containing <i>u</i>-constacyclic codes over <i>R</i>. Finally, we define another class of maps, which changes the Hermitian dual-containing property of linear codes over <i>R</i> into the trace dual-containing property of linear codes over <span>(mathbb {F}_{q^{2m}})</span>. Using Symplectic construction, another class of <span>(q^{m})</span>-ary quantum codes are obtained from Hermitian dual-containing <i>u</i>-constacyclic codes over <i>R</i>.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148926381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Quantum-state discrimination and which-crystal information in induced-coherence interferometry","authors":"L. Theerthagiri","doi":"10.1007/s11128-026-05331-w","DOIUrl":"10.1007/s11128-026-05331-w","url":null,"abstract":"<div><p>Quantum-state discrimination provides a fundamental framework for extracting information from nonorthogonal quantum states. In this work, we present an operational formulation of wave–particle complementarity in the low-gain Zou–Wang–Mandel (ZWM) induced-coherence interferometer. In this regime, each photon pair is emitted by one of two nonlinear crystals, preparing nonorthogonal conditional idler states that encode which-crystal information and define a binary quantum hypothesis-testing problem. We analyze which-crystal inference using both unambiguous state discrimination (Ivanovic–Dieks–Peres, IDP) and minimum-error discrimination (Helstrom bound). We identify a correspondence between the signal visibility and the optimal inconclusive probability of unambiguous discrimination, while the Helstrom bound characterizes the optimal success probability for source identification. The Helstrom and IDP interpretations developed here apply specifically to the low-gain binary single-pair sector. At arbitrary parametric gain, idler-seeded emission produces unequal signal intensities and modifies the ordinary fringe visibility; the appropriate all-gain formulation instead involves normalized first-order coherence and a correlation-based distinguishability. This formulation provides an operational perspective on complementarity in induced coherence, emphasizing the role of measurement in determining accessible which-crystal information. We further extend the analysis to thermal noise in the object arm, where the idler states become mixed, leading to reduced visibility and distinguishability consistent with mixed-state-discrimination limits. The approach is general and applicable to two-path interferometers with marker degrees of freedom.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148928070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Multi-Unary: a dense input encoding scheme for the quantum circuit model","authors":"Diego Alonso,&nbsp;Pedro Sánchez,&nbsp;Bárbara Álvarez,&nbsp;Fernando Terroso-Sáenz","doi":"10.1007/s11128-026-05316-9","DOIUrl":"10.1007/s11128-026-05316-9","url":null,"abstract":"<div><p>The choice of a given encoding scheme for the problem variables, represented by a set of input qubits of a quantum circuit, substantially influences its design, as well as the quantity and nature of quantum resources (qubits and gates) employed by it. Quantum programmers have access to a variety of encoding strategies, such as one-hot, binary, Gray, amplitude encoding, or Schmidt decomposition, but each of them allows encoding just a single value for each problem variable. This article introduces a novel encoding scheme based on one-hot encoding, termed Multi-Unary, which enables the representation of multiple values within the input qubits, hence the descriptor ‘dense encoding scheme.’ The application of Multi-Unary is demonstrated in the context of the graph coloring problem using Grover’s algorithm, although its applicability extends to a broader class of quantum algorithms. By increasing the informational density on the input qubits, the multi-unary encoding offers potential advantages in terms of circuit compactness and resource efficiency, while at the same time enables an output value to contain more than one solution to a problem. Given its simple implementation, it can even replace the one-hot encoding scheme.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11128-026-05316-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148928071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geometry of the symplectic group and optimal EAQECC codes","authors":"Ruihu Li,&nbsp;Yuezhen Ren,&nbsp;Chaofeng Guan,&nbsp;Yang Liu","doi":"10.1007/s11128-026-05333-8","DOIUrl":"10.1007/s11128-026-05333-8","url":null,"abstract":"<div><p>A new link between the geometry of the symplectic group and entanglement-assisted (EA) quantum error-correcting codes (EAQECCs) is presented. Relations between symplectic subspaces and quaternary additive codes concerning the parameters of EAQECCs are described. Consequently, parameters of EA stabilizer codes are revealed within the framework of additive codes. Our techniques enable us to solve some open problems regarding optimal EAQECCs and entanglement-assisted quantum minimum distance separable (EAQMDS) codes and are also useful for designing encoding and decoding quantum circuits for EA stabilizer codes.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148928012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Steane [[7,1,3]] outer coding for loss-tolerant one-way quantum repeaters","authors":"Subhan Zawad Bihan,&nbsp;Anindya Kishore Choudhury,&nbsp;Sajid Muhaimin Choudhury","doi":"10.1007/s11128-026-05327-6","DOIUrl":"10.1007/s11128-026-05327-6","url":null,"abstract":"<div><p>Long-distance quantum communication requires architectures that withstand photon loss and operational noise without relying on two-way classical signalling that incurs round-trip latency. Motivated by recent hybrid designs combining photonic trees with small stabilizer codes, we benchmark the Steane code [[7, 1, 3]] against the standard five-qubit [[5, 1, 3]] baseline within a tree-assisted repeater architecture. Unlike the saturated five-qubit code, which is constrained by a fully populated syndrome space, our implementation exploits the Steane code’s underpopulated syndrome space to correct all single-qubit erasures and additionally a subset of two-qubit errors. Consequently, the Steane code demonstrates superior robustness at realistic re-encoding error rates (<span>(epsilon _{r}ge 0.05%)</span>), maintaining higher message qubit transmission success rates than the baseline. Notably, at <span>(epsilon _{r}=0.2%)</span>, the Steane-based repeater maintains a competitive cost threshold up to 5000 km, significantly exceeding the 800 km limit of the five-qubit code. These results suggest that the Steane code’s capacity for erasure correction offers a practical advantage for one-way repeaters, outweighing the overhead of its larger block size.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148838021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Lightweight targeted estimation of layout noise in a quantum computer using quality indicator circuits","authors":"Shikhar Srivastava,&nbsp;Ritajit Majumdar,&nbsp;Padmanabha Venkatagiri Seshadri,&nbsp;Anupama Ray,&nbsp;Yogesh Simmhan","doi":"10.1007/s11128-026-05326-7","DOIUrl":"10.1007/s11128-026-05326-7","url":null,"abstract":"<div><p>Minimizing noise is essential for reliably executing quantum circuits on the current generation of hardware. The mapping of an abstract quantum circuit to the physical layout of the quantum hardware significantly influences the output quality since hardware noise profiles are non-uniform and dynamic. Existing solutions such as Mapomatic rely on stale calibrations while just-in-time (JIT) transpilation has high hardware usage. We propose quality indicator circuits (QICs) as a lightweight probe circuit synthesized from the user circuit, whose ideal noiseless outcome is known. QIC helps decide the region of the quantum hardware best suited for the given circuit. We propose QIC execution for each isomorphic layout, and an alternative approach where a union of multiple layouts are executed together for lower overheads. Our results show QIC to outperform Mapomatic in the quality of layout selection while having <span>(79%)</span> lower hardware overheads than JIT. This makes our QIC method lightweight, reliable and a viable technique for layout selection in near-term quantum devices.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148837976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Implementation of a quantum sequence alignment algorithm for quantum bioinformatics","authors":"Floyd M. Creevey,&nbsp;Mingrui Jing,&nbsp;Lloyd C. L. Hollenberg","doi":"10.1007/s11128-026-05274-2","DOIUrl":"10.1007/s11128-026-05274-2","url":null,"abstract":"<div><p>This paper presents the implementation of a quantum sequence alignment (QSA) algorithm on biological data in environments simulating noisy intermediate-scale quantum (NISQ) computers. The approach to quantum bioinformatics adapts the original QSA algorithm proposed in 2000 to current capabilities and limitations of NISQ-era quantum computers and uses a genetic algorithm for state preparation (GASP) to create encoding circuits to load both database and target sequences into the quantum data registers. The implementation is tested in a simulated quantum computer environment to validate the approach and refine the GASP data-loading circuit designs. The results demonstrate the practicalities of deploying the QSA algorithm and exemplify the potential of GASP for data encoding in the realm of quantum circuit design, particularly for complex algorithms in quantum bioinformatics and other data-rich problems.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11128-026-05274-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148837596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Statistical correlators and tripartite entanglement","authors":"Sakil Khan,&nbsp;Dipankar Home,&nbsp;Urbasi Sinha,&nbsp;Sachin Jain","doi":"10.1007/s11128-026-05325-8","DOIUrl":"10.1007/s11128-026-05325-8","url":null,"abstract":"<div><p>It has recently been argued that among the various suggested measures of tripartite entanglement, the two particular measures, viz. the Concurrence Fill and the Genuine Multipartite Concurrence, are the only ‘genuine’ tripartite entanglement measures based on certain suitably specified criteria. In this context, we show that these two genuine tripartite entanglement measures can be empirically determined for the two important classes of tripartite entangled states, viz. the generalized GHZ and the generalized W states using the derived relationships of these two measures with the observable statistical correlators like the Pearson correlator and mutual information. Such a formulated scheme would therefore provide for the first time the means to exactly quantify tripartite entanglement, crucial for the proper assessment of its efficacy as resource. We also point out two specific applications of this scheme, viz. (a) enabling empirical demonstration of the potentially significant feature of inequivalence between Concurrence Fill and Genuine Multipartite Concurrence in quantitatively assessing which of the two given tripartite states is more entangled than the other one and (b) enabling experimental detection of the recently predicted phenomenon of entanglement sudden death for a tripartite system.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148837564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Quantum gradient-based approach for edge and corner detection using Sobel kernels","authors":"Mohammad Aamir Sohail,&nbsp;Gabriela Pinheiro,&nbsp;Yasemin Poyraz Koçak,&nbsp;Batuhan Hangun,&nbsp;Emre Camkerten,&nbsp;Simge Yiğit,&nbsp;Hafize Asude Ertan","doi":"10.1007/s11128-026-05311-0","DOIUrl":"10.1007/s11128-026-05311-0","url":null,"abstract":"<div><p>Edge detection refers to the process of identifying points in a digital image where the intensity changes sharply, typically indicating object boundaries or structural features. Corners are locations where the gray value intensity changes abruptly in multiple directions and are widely used in feature extraction, object tracking, and 3D modeling. In this study, we present a quantum implementation of Sobel-based edge detection and Harris-style corner detection. Two quantum image encoding methods: Flexible Representation of Quantum Images (FRQI) and Quantum Probability Image Encoding (QPIE), are employed to encode the input data, and their behavior is comparatively analyzed. The proposed approach introduces a quantum gradient computation scheme based on lag-2 differences, which enables the evaluation of gradient-like features in superposition. To improve detection quality and eliminate false positives, a classical post-processing step is applied to candidate corner points identified by the quantum circuit. The results demonstrate that the proposed quantum circuits produce edge and corner detection outputs that are qualitatively consistent with classical Sobel and Harris operators. Furthermore, the QPIE-based configuration yields more stable and structurally coherent results than its FRQI-based counterpart, while demonstrating greater robustness under limited measurement shots in the image reconstruction experiments. While the gradient computation can be performed efficiently at the circuit subroutine level, the overall computational cost remains dominated by state preparation, measurement, and classical post-processing steps. All experiments are conducted under noiseless simulation conditions, and practical performance on NISQ hardware may be affected by noise, measurement overhead, and finite-shot statistics. Therefore, the present work primarily demonstrates a functional and scalable quantum realization of classical edge and corner detection methods, rather than an end-to-end computational speedup.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148837580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}

{"title":"Efficient discrimination schemes for unextendible product bases with strong quantum nonlocality","authors":"Qiqi Feng,&nbsp;Huaqi Zhou,&nbsp;Limin Gao","doi":"10.1007/s11128-026-05310-1","DOIUrl":"10.1007/s11128-026-05310-1","url":null,"abstract":"<div><p>Entanglement is a central resource in quantum information science, and it is therefore important to design local discrimination protocols that minimize entanglement cost. In this paper, we propose several entanglement-assisted discrimination schemes for the local discrimination of a representative strongly nonlocal unextendible product basis (UPB) in a <span>(3otimes 3otimes 3)</span> system. By exploiting the structure of the UPB and the properties of maximally entangled resources, we generalize the protocols to a family of strongly nonlocal UPBs in <span>(dotimes dotimes d)</span> systems. In particular, we show that these UPBs can be perfectly distinguished using two bipartite maximally entangled states, distributed between different pairs of parties, without employing quantum teleportation. We further compare the total supplied and average consumed entanglement under a clearly specified accounting convention. The results demonstrate that avoiding teleportation can reduce the required entanglement in suitable resource-allocation scenarios and clarify the operational role of low-dimensional maximally entangled resources.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148782863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}