Quantum Information Processing最新文献

{"title":"Significance of special perfect entanglers in quantum Volunteers’ Dilemma","authors":"Trishanjit Das,&nbsp;S. Balakrishnan","doi":"10.1007/s11128-026-05372-1","DOIUrl":"10.1007/s11128-026-05372-1","url":null,"abstract":"<div><p>Eisert–Wilkens–Lewenstein (EWL) approach is a standard quantization scheme using which classical games can be analyzed. In this present work, we study the quantization of the classical Wessie–Franzen Volunteers’ Dilemma, where cost of volunteering is shared equally among the volunteers. When we use general EWL scheme for 2-player Volunteers’ Dilemma game, a local equivalence class of Controlled NOT (CNOT) is the only option that can achieve the Pareto Optimal Symmetric Nash Payoff. However, by modifying the EWL framework and changing the strategy profile, we construct a general expression that provides us with more flexible combinations which are a local equivalence class of special perfect entanglers (SPEs). Our findings reveal the importance of SPEs in quantum games like the Quantum Volunteers’ Dilemma, thereby underscoring a strategic advantage of decision-making in quantum settings.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 11","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149338607","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":"An improved Quantum Neural Network with adaptive phase–amplitude processing for nonlinear system modeling","authors":"Rajesh Kumar","doi":"10.1007/s11128-026-05397-6","DOIUrl":"10.1007/s11128-026-05397-6","url":null,"abstract":"<div><p>This paper presents a Modified Quantum Neural Network (MQNN) framework designed as an enhanced version of the classical Quantum Neural Network (QNN) for modeling nonlinear dynamic systems. The objective of this work is not to compete with other neural network architectures, but rather to refine and improve the fundamental QNN structure. The MQNN introduces key modifications at both the input encoding and output processing stages. Unlike the conventional QNN, which applies a sigmoid transformation prior to phase modulation, the MQNN directly maps raw inputs into phase values. This direct phase encoding broadens the representational capacity of the hidden-layer quantum neurons and enables them to capture richer nonlinear phase interactions. Additionally, the traditional trigonometric interference-based output neuron is replaced with a trainable amplitude–bias output unit, where the output scaling coefficient <span>(C_{o})</span> and bias term <span>(w_{o})</span> are adaptively tuned during learning. This modification simplifies the output mapping and enhances the network’s ability to normalize and dynamically scale its output. All parameters are updated through gradient-based learning to ensure stable convergence. The performance of the MQNN is evaluated on three benchmark nonlinear dynamic systems and compared solely with the classical QNN under identical conditions. Simulation results demonstrate that the MQNN achieves faster convergence, lower mean-square error, and improved generalization capability, confirming its effectiveness as a refined quantum-inspired modeling framework.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 11","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149338598","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":"Information-Induced Shielding in Open Quantum Systems: A Bidirectional Perspective on Type-2 Epistemic Uncertainty and Entropy Dynamics","authors":"Kung-Ming Lan","doi":"10.1007/s11128-026-05384-x","DOIUrl":"10.1007/s11128-026-05384-x","url":null,"abstract":"<div><p>We describe a self-shielding mechanism in open quantum systems by coupling Lindblad dynamics with an interval Type-2 fuzzy observer model. To avoid conceptual ambiguities associated with physical measurement apparatuses, we model the environment as an information-theoretic agent characterized by bounded cognitive resolution. We identify a stability regime characterized by a stable steady state. By formulating the mathematical expansion of the footprint of uncertainty (FOU), our comparative dynamics reveal that as the system’s back-action strength (<i>k</i>) increases, the observer’s reduced resolution significantly suppresses both the effective decoherence rate and the growth of Von Neumann entropy. This protective phase is evaluated through extensive stochastic simulations (<span>(N=1000)</span>) and continuous crossover mapping, offering a theoretical framework for understanding the quantum-to-classical transition in complex, high-noise environments.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 11","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149338602","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":"EAQECCs from constacyclic codes over the finite non-chain ring (mathbb {F}_{q}[v]/langle v^3-vrangle )","authors":"Juan Li,&nbsp;Yunbo Tian,&nbsp;Fanghui Ma","doi":"10.1007/s11128-026-05396-7","DOIUrl":"10.1007/s11128-026-05396-7","url":null,"abstract":"<div><p>Let <span>( R=mathbb {F}_q[v]/langle v^3-vrangle )</span> be a finite non-chain ring, where <span>(q)</span> is an odd prime power. In this paper, we construct a class of entanglement-assisted quantum error-correcting codes (EAQECCs), including some maximal entanglement entanglement-assisted quantum error-correcting codes (ME-EAQECCs) via the Gray images of constacyclic codes over <span>(R)</span>. Several such codes are presented to demonstrate the effectiveness of our construction. Moreover, the codes constructed in this work are new, and their parameters are superior to those of the known EAQECCs provided in [1].</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 11","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149338601","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":"Modelling optimal implementation of an arbitrary N-qubit quantum gate within the generalized Bloch vectors formalism","authors":"Elena R. Loubenets,&nbsp;Sergey Kuznetsov","doi":"10.1007/s11128-026-05378-9","DOIUrl":"10.1007/s11128-026-05378-9","url":null,"abstract":"<div><p>The optimal implementation of quantum gates for closed <i>N</i>-qubit systems is one of the key challenges for practical realization of many quantum information processing tasks. In the present article, based on the generalized Bloch vectors formalism [J. Phys. A: Math. Theor. 54, 195301 (2021)] for a finite-dimensional quantum system, we develop a new <i>general</i> model for the optimal implementation of quantum gates, which is formulated in terms of the Bloch vectors for the unitary evolution operator and the system Hamiltonians, drift and control, and has the unified mathematical form, which is standard for the mathematical control theory and applicable for the implementation of an arbitrary <i>N</i>-qubit gate within any closed <i>N</i>-qubit system, satisfying the controllability conditions. Within the developed optimal model, the cost functional has both the terminal part and also, the integral part with the special scaling, and this allows us to specify the quantum optimal control synthesis via solving the two-point boundary value problem (BVP) for the system of ordinary differential equations (ODEs), which can be explored numerically by any of the known BVP solvers for ODEs. The numerical experiments, conducted for the implementation within the developed optimal model of a variety of <span>(N=1,2,3)</span> qubit gates, demonstrate the high accuracy of the model-based results.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 11","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149338099","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":"Improvements on quantum designated-verifier signature based on Bell states","authors":"Cai Zhang,&nbsp;Kechuan Li,&nbsp;Zhiwei Sun","doi":"10.1007/s11128-026-05386-9","DOIUrl":"10.1007/s11128-026-05386-9","url":null,"abstract":"<div><p>Quantum designated-verifier signature (QDVS) is a cryptographic scheme based on quantum mechanics in which a signature can be verified only by a specific designated verifier. Recently, Xin et al. [31] proposed a QDVS scheme based on Bell states and claimed that it was secure. However, we demonstrate that their scheme is vulnerable to forgery attacks. To overcome this vulnerability, we propose an improved QDVS scheme utilizing single qubits, a secret random permutation, and unitary operations. Security analysis shows that the proposed scheme satisfies the required designated-verifier security properties while resisting various attacks. Compared with representative QDVS schemes, our scheme requires neither a third party (TP) nor quantum entanglement resources, and achieves a qubit efficiency of <span>(100%)</span> with a quantum cost of one qubit per signed bit and only two quantum communication rounds.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 11","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149338365","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":"Global coherence: the genuine quantum resource in discord for quantum information tasks","authors":"Chellasamy Jebarathinam,&nbsp;Huan-Yu Ku,&nbsp;Hao-Chung Cheng,&nbsp;Hsi-Sheng Goan","doi":"10.1007/s11128-026-05379-8","DOIUrl":"10.1007/s11128-026-05379-8","url":null,"abstract":"<div><p>Quantum discord is an information-theoretic measure of non-classical correlations between quantum subsystems. It can assume nonzero values even for separable (i.e., non-entangled) mixed states and characterizes the specifically quantum component of correlations that is not captured by entanglement measures alone. Quantum discord does not capture genuinely quantum correlations in general. This work introduces the concept of <i>global coherence</i> to represent genuinely quantum correlations in discord. Global coherence in a bipartite system is defined as bipartite coherence that cannot be attributed to local coherence in either subsystem alone, and is operationally characterized by discordant states with a correlation matrix rank exceeding the minimum subsystem dimension. We introduce the resource theory of global coherence, in which any local operations of the form <span>(Phi _A otimes Phi _B)</span> are free operations, while classical randomness is not freely available. We establish that global coherence is necessary for semi-device-independent steerability, analogous to how entanglement is necessary for standard steering. Furthermore, for remote state preparation using two-qubit states, we identify a necessary and sufficient quantum resource by introducing a global coherence quantifier. Finally, we establish a hierarchy of correlations in bipartite quantum states and illuminate the relationship between coherence, discord, and entanglement. Our work clarifies the precise quantum resource underlying discord-based quantum information protocols and demonstrates that genuinely quantum correlation, as captured by global coherence, enables operational advantages beyond those achievable with locally coherent states.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 11","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149339489","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":"Lieprune with compact lie group and noncommutative geometry for QNN pruning without barren plateaus","authors":"Xing Deng,&nbsp;Xiang Li,&nbsp;Haijian Shao,&nbsp;Lihao Qiu,&nbsp;Jinkun Shen,&nbsp;Yingtao Jiang","doi":"10.1007/s11128-026-05366-z","DOIUrl":"10.1007/s11128-026-05366-z","url":null,"abstract":"<div><p>Quantum neural networks (QNNs) often suffer from barren plateaus, unstable gradient estimation, and excessive parameter redundancy, which jointly limit the trainability and scalability of variational quantum models. Although structured pruning can reduce the complexity of quantum circuits, its impact on the underlying optimization geometry and trainability remains insufficiently understood. In this work, we develop a unified theoretical framework for LiePrune by integrating Lie-algebraic structured compression, compact Lie group geometry, and noncommutative spectral analysis. Starting from an over-parameterized QNN with a high-dimensional Lie algebra, LiePrune identifies redundant generator directions through quantum Fisher information and performs structured geometric compression, inducing an effective Lie algebra, a compact subgroup, and a reduced effective tangent geometry. Based on this compressed geometry, we establish two complementary theoretical guarantees. First, under compact Lie group constraints, we prove a non-vanishing lower bound on the gradient variance over the effective subspace, thereby avoiding exponential gradient collapse associated with barren plateaus. Second, by characterizing the pruned model through a noncommutative spectral structure, we derive a finite-shot upper bound on the mean-squared error of the parameter-shift gradient estimator that scales with the effective spectral complexity and the number of measurements. Together, these results establish a compression–trainability compatibility between aggressive parameter reduction, stable gradient behavior, and tractable gradient estimation. Extensive experiments on Bars-and-Stripes validate the theoretical analysis by confirming gradient-variance scaling with system size, finite-shot MSE scaling with the number of measurement shots, and robust predictive performance under high compression ratios. Compared with random pruning and GradNorm pruning, LiePrune demonstrates improved robustness and trainability under aggressive parameter compression. The proposed framework provides a mathematically grounded approach to quantum neural network compression, showing how Lie-algebraic redundancy reduction can reshape the effective optimization geometry and enable scalable, trainable, and measurement-efficient quantum learning.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 11","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149339276","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":"Injectivity of G-fusion frames for quantum state identification","authors":"Mehdi Rashidi-Kouchi","doi":"10.1007/s11128-026-05376-x","DOIUrl":"10.1007/s11128-026-05376-x","url":null,"abstract":"<div><p>We investigate the injectivity problem for g-fusion frames of Hilbert-Schmidt operators and its relation to unique identification of quantum states from measurement statistics. A g-fusion frame combines a family of closed subspaces of a Hilbert space with operator-valued measurements acting into auxiliary Hilbert spaces. For the induced measurement operators <span>(A_i = Lambda _i P_{W_i})</span>, we define the measurement map on self-adjoint Schatten-class operators by <span>(m_i(T) = {{,textrm{tr},}}(A_i T A_i^*))</span>. We prove equivalent characterizations of injectivity in the Hilbert-Schmidt and trace-class settings. The key step is an explicit Jordan decomposition of a self-adjoint operator into its positive and negative parts; no common eigenbasis assumption for two arbitrary positive operators is required. We then interpret the trace-class result on density operators and explain its relation to informationally complete quantum measurements. A finite-dimensional qubit example illustrates how a subspace-based g-fusion construction can generate an informationally complete measurement scheme. The contribution is an injectivity criterion for a structured class of operator-valued measurements; it is not a claim of universal computational superiority over arbitrary POVMs or full quantum tomography.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 11","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149339256","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":"Fast implementation of controlled (pi ) phase gate using superadiabatic shortcuts with Rydberg superatoms","authors":"R. B. Zhao,&nbsp;W. Li,&nbsp;Y. Q. Ji,&nbsp;J. Wang,&nbsp;S. B. Jiang,&nbsp;X. M. Xiu","doi":"10.1007/s11128-026-05370-3","DOIUrl":"10.1007/s11128-026-05370-3","url":null,"abstract":"<div><p>Quantum phase gates serve as core fundamental resources for quantum information processing, and their preparation efficiency and structural stability directly determine the overall performance of quantum computing and quantum communication. The traditional adiabatic preparation method is prone to the influence of decoherence due to its excessive time consumption, while superadiabatic shortcut technology can significantly shorten the evolution time while retaining the advantages of the adiabatic process. In this paper, we propose a scheme for rapidly implementing a quantum phase gate by combining superadiabatic scheme and quantum Zeno dynamics to construct shortcuts to adiabatic passage. We demonstrate the superadiabatic shortcut by using Rydberg superatoms in a distant-atom-cavity system. Furthermore, we utilize the controlled <span>(pi )</span> phase gate to achieve the preparation of N-particle cluster state. In addition, the effects of decoherence and operational errors induced by various parameters are discussed. Numerical simulation demonstrates the proposed scheme has high fidelities and robustness against both cavity leakage and atomic spontaneous emission. Different from previous superadiabatic shortcut schemes, our protocol adopts second-order iterative counterdiabatic driving to avoid experimentally inaccessible direct couplings, where the counterdiabatic correction is realized merely by reshaping feasible Gaussian laser pulses. Furthermore, we analyze the scalability of cascaded controlled <span>(pi )</span> phase gate for generating N-particle cluster state under realistic decoherence sources.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 11","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149339254","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}