Quantum Information Processing最新文献

{"title":"An optimal hybrid quantum-classical representation for robust photonic image processing on NISQ devices","authors":"Nouioua Tarek","doi":"10.1007/s11128-026-05314-x","DOIUrl":"10.1007/s11128-026-05314-x","url":null,"abstract":"<div><p>Quantum image processing (QIP) promises significant advantages for computer vision, but its realization on Noisy Intermediate-Scale Quantum (NISQ) devices is hampered by a fundamental trade-off between qubit efficiency and measurement robustness. This work introduces a novel hybrid quantum-classical representation that optimizes this trade-off for discrete-variable photonic quantum hardware using path-encoded qubits. Through a dual optimization approach combining simulation-based ablation study and mathematical optimization with bootstrap validation (1000 resamples), we derive an optimal operating point of <span>(alpha = 0.393 pm 0.019)</span> (95% CI: 0.355−0.424). This value is universal: it balances qubit count against measurement fidelity under the assumed NISQ hardware characteristics and is independent of the specific image content. Our architecture requires only <span>(Q = lceil log _2(N^2) rceil + 4)</span> qubits for an <span>(N times N)</span> image, achieving logarithmic scaling while maintaining measurement fidelity between 0.92−0.97 on simulated NISQ hardware. We provide complete photonic circuit designs utilizing path encoding, including resource estimates for optical components. Comprehensive performance analysis demonstrates a 38% improvement in error resilience over FRQI, while using only one additional control qubit compared to NEQR under equivalent color depth (3 bits, 8 levels). For applications where 8-level color is sufficient, this modest overhead is offset by superior measurement robustness and noise tolerance. Measurement distribution analysis confirms well-separated operational modes with minimal overlap, indicating excellent discrimination capability. This work establishes a practical and scalable framework for implementing QIP on imminent discrete-variable photonic quantum processors.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148782678","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":"Rate-compatible QC-LDPC reconciliation via channel-confidence estimation in QKD systems","authors":"Xinyu Liu,&nbsp;Yan Wang,&nbsp;Tong Wang,&nbsp;Yue Zhang,&nbsp;Yingying Tai","doi":"10.1007/s11128-026-05324-9","DOIUrl":"10.1007/s11128-026-05324-9","url":null,"abstract":"<div><p>The efficiency of information reconciliation in quantum key distribution (QKD) is significantly constrained by the dynamic, time-varying nature of quantum channels. Conventional post-processing schemes relying on fixed parameters suffer from bandwidth inefficiency during periods of low error rates and face a high risk of link outages when error rates spike. To address these issues, we propose a dual-adaptive post-processing framework utilizing IEEE 802.11n standard QC-LDPC codes. First, we introduce a dynamic parameter-estimation strategy based on channel confidence. This approach adapts the check ratio while maintaining a fixed statistical confidence target. Second, we implement a rate-compatible error correction scheme employing puncturing and shortening techniques to accommodate substantial channel fluctuations. The check-ratio, QBER-threshold, and rate selections are validated through a constrained policy-grid search, realistic-channel LDPC-level decoding experiments and a separate QBER-anomaly-detection test. In the stable low-QBER scenario, the safety-constrained policy with check ratios <span>({8%,12%,32%})</span> and rates <span>({0.56,0.52,0.33})</span> achieves a total normalized SKR of <span>(146.360pm 2.951)</span>, corresponding to an <span>(11.34%pm 0.21%)</span> gain over the fixed benchmark, while maintaining <span>(99.59%pm 0.10%)</span> decoding availability. With <span>(n_{textrm{sift}}=10^5)</span>, the security-anomaly test gives zero no-attack false alarms, <span>(100%)</span> detection for tested sustained attacks with QBER at least <span>(8%)</span>, and <span>(100%)</span> abort probability for tested attacks with QBER at least <span>(11%)</span>. These results show that the proposed architecture provides a controllable trade-off between efficiency, robustness, and security-aware parameter estimation in dynamic quantum channels.\u0000</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148782027","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 image processing filters based on FRQI representation","authors":"Amir Hossein Salehi Shayegan","doi":"10.1007/s11128-026-05321-y","DOIUrl":"10.1007/s11128-026-05321-y","url":null,"abstract":"<div><p>Quantum image processing exploits quantum mechanical phenomena such as superposition and entanglement to achieve computational advantages over classical methods. This paper presents a comprehensive framework for quantum image filtering based on the Flexible Representation of Quantum Images (FRQI). We develop four quantum filters targeting fundamental image processing tasks. First, a <i>quantum thresholding filter</i> (QTF) employs Grover’s amplitude amplification to identify pixels exceeding an intensity threshold with quadratic speedup <span>(mathcal {O}(sqrt{N/M}))</span> over classical linear search, where <i>N</i> is the total number of pixels and <i>M</i> is the number of marked pixels. Second, a <i>quantum object recognition filter</i> (QORF) combines SWAP-test fidelity estimation with Grover search to perform template matching, achieving <span>(mathcal {O}(sqrt{M/L}))</span> query complexity for identifying <i>L</i> matching patches among <i>M</i> candidates. Third, a <i>quantum Hadamard edge detection</i> (QHED) algorithm extracts horizontal, vertical and diagonal edges with <span>( mathcal {O}(log N) )</span> gate complexity. Fourth, a <i>quantum blur filter</i> (QBF) performs low-pass filtering using the Walsh–Hadamard transform with only <span>(mathcal {O}(log N))</span> quantum gates, compared to <span>(mathcal {O}(N log N))</span> for classical FFT-based convolution. For each filter, we provide rigorous mathematical formulations, explicit quantum circuit constructions and complexity analyses. We also discuss practical limitations including FRQI state preparation overhead, measurement complexity and NISQ hardware constraints. This paper establishes a unified quantum image processing framework that bridges theoretical quantum speedups with implementable circuit designs, providing a foundation for future developments in quantum-enhanced computer vision.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148782302","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":"Realising the standard quantum limit uniformly through intensity measurements on spin coherent light","authors":"Dakshin Tillo,&nbsp;J. Solomon Ivan","doi":"10.1007/s11128-026-05313-y","DOIUrl":"10.1007/s11128-026-05313-y","url":null,"abstract":"<div><p>We obtain uniform phase sensitivity of <span>(frac{1}{sqrt{langle Nrangle }})</span> using spin coherent light. It is shown that two-mode non-classicality is essential for uniform phase sensitivity in the standard quantum limit. Spin coherent light is realised by detecting <i>N</i> photons sequentially in a time-differential manner from a coherent light source. The coherence of the spin coherent state is seen to be retained even while using inefficient detectors and in the presence of quantum-limited loss in the interferometer. The working principle is demonstrated experimentally in a Mach–Zehnder interferometer and a polarisation interferometer for the choice of <span>( N = 400)</span> using a commercially available <span>(632.8,,textrm{nm})</span> laser source. The <span>(1/sqrt{N})</span> scaling in phase sensitivity is checked for other values of <i>N</i>. Non-classicality of the detected photons is experimentally demonstrated.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148751753","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":"Characterizing mixed-state and first excited-state phase transitions in the one-dimensional ({J}_1)–({J}_2) Heisenberg spin-1/2 chain","authors":"Jia Bao,&nbsp;Hongying Liu,&nbsp;Longhui Shen,&nbsp;Bin Guo","doi":"10.1007/s11128-026-05320-z","DOIUrl":"10.1007/s11128-026-05320-z","url":null,"abstract":"<div><p>We study the one-dimensional frustrated <span>(J_{1}-J_{2})</span> Heisenberg spin-1/2 model under periodic boundary conditions, focusing on quantum criticality induced by competing interactions and parity-dependent frustration. Using quantum discord (QD) and global quantum discord (GQD), we analyze phase transitions in mixed and first excited states, revealing clear parity effects: even-length chains show a single energy level crossing and a sharp derivative anomaly near the singular point, which extrapolates to the thermodynamic infinite-order Berezinskii–Kosterlitz–Thouless phase transition point <span>(lambda _{c}(infty )approx 0.241)</span> (<span>(lambda =J_{2}/J_{1})</span>) marking the Luttinger liquid to dimerized phase transition; odd-length chains exhibit two crossings but no abrupt transition. This smoothing effect is physically rooted in the true geometric frustration inherent to a periodic ring with an odd number of sites, which prohibits perfect dimerization and drives a comprehensive spectral reorganization and state hybridization among the low-lying excited states under low-energy state truncation. The resulting thermal stability of QD and GQD in odd-length chains, valid within the low-temperature regime, offers insights for the design of quantum memory platforms in frustrated systems. Our results highlight QD and GQD as effective probes of parity-resolved quantum phase transitions in frustrated low-dimensional systems.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148751712","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":"A multi-objective quantum-inspired artificial bee colony optimization algorithm based on the Bloch sphere","authors":"Yuwei Huang,&nbsp;Lefeng Wang,&nbsp;Gang Xu,&nbsp;Yong Lu,&nbsp;Weijie Tan,&nbsp;Xiu-Bo Chen,&nbsp;Zongpeng Li","doi":"10.1007/s11128-026-05317-8","DOIUrl":"10.1007/s11128-026-05317-8","url":null,"abstract":"<div><p>This study presents improved quantum-inspired artificial bee colony algorithm based on the Bloch sphere for multi-objective optimization with particular application to wireless communication security. Firstly, an innovative quantum-inspired artificial bee colony framework for multi-objective optimization is proposed, whose encoding is adopted on the Bloch sphere instead of a quantum bit to extend the feasible solution space, under the control of two development strategies to enhance the accuracy and efficiency of the search. Secondly, tailored updating mechanisms are implemented for different swarm stages, which have undergone enhancements by elite class, alternating search, and adaptive guidance. The quantum rotation angles compatible with this algorithm are designed to accelerate the optimization to improve the overall performance. Furthermore, the proposed algorithm is designed to solve the optimization problem of the wireless communication model in the presence of an intelligent reflective surface with multi objectives. The security and performance are jointly improved through the simultaneous optimization of the security rate and base station beamforming. Experimental comparisons with classical multi-objective algorithms on benchmark test suites demonstrate that the algorithm can consistently converge to the Pareto-optimal frontier and shows significant advantages in GD, Spread, IGD, and run time. It achieves an average improvement of 15.6% in the Spread compared to MOABC, while maintaining competitive convergence metrics and reducing the average computational time by 7.08%, confirming its effectiveness in conducting multi-objective optimization. Moreover, the algorithm demonstrates practical value in wireless communication applications by effectively optimizing both secrecy rate and beamforming performance.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148752019","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":"Teleportation of quantum Fisher information with Gaussian states","authors":"Payman Mahmoudi,&nbsp;Somayeh Mehrabankar,&nbsp;Aurelian Isar","doi":"10.1007/s11128-026-05306-x","DOIUrl":"10.1007/s11128-026-05306-x","url":null,"abstract":"<div><p>Quantum Fisher Information (QFI), which sets the fundamental bound on parameter estimation precision via the quantum Cramér-Rao inequality, is investigated for a general single-mode Gaussian state before and after teleportation. Using a two-mode squeezed vacuum state as a shared entanglement resource between Alice and Bob, we analyze the teleportation protocol under environmental noise, focusing on diffusion and dissipation induced by a thermal bath. By comparing QFI for several parameters of the input state before and after teleportation, we evaluate the effectiveness of QFI transfer. We find that increasing the squeezing of the shared state enhances QFI preservation. Notably, under certain conditions, environmental interactions can help maintain QFI, particularly for shared states with high frequency, suggesting a subtle interplay between system dynamics and decoherence.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11128-026-05306-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148751742","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":"Variational quantum Kolmogorov–Arnold network","authors":"Hikaru Wakaura,&nbsp;Rahmat Mulyawan,&nbsp;Andriyan B. Suksmono","doi":"10.1007/s11128-026-05284-0","DOIUrl":"10.1007/s11128-026-05284-0","url":null,"abstract":"<div><p>In this paper, we introduce the variational quantum Kolmogorov–Arnold network (VQKAN), a novel framework for quantum machine learning that uses measurement results of qubits as neurons and quantum gates as synapses. VQKAN is applied to multi-dimensional function fitting and binary classification tasks, where it shows reduced overfitting and competitive accuracy compared to a baseline quantum neural network (QNN) under the conditions tested. We also evaluate VQKAN on a Fourier partial differential equation; on that task, VQKAN does not surpass QNN, QCNN, TTN, or LSTM baselines, and we report this negative result and discuss its implications. Empirically, the per-iteration computation time grows sub-cubically with the number of qubits over the tested range <span>(N_qin [2,8])</span> (best fit <span>(Tpropto N_q^{2.5})</span>, <span>(R^2{=}0.99)</span>); a pure logarithmic fit is rejected (<span>(R^2{=}0.78)</span>). Within this practical regime, VQKAN offers a favourable trade-off between accuracy and gate count. A key empirical strength of VQKAN is reduced overfitting on the tested fitting tasks compared to QNN, allowing for better generalization even with limited data. Additionally, we present a modified compact ansatz that further enhances accuracy on the regression benchmark; on the classification benchmark, this ansatz is more expressive but more expensive and is not competitive with the canonical ansatz under MAE, a negative result we report alongside the positive one. All numerical experiments use noiseless statevector simulation; we further provide a finite-shot study (256–4096 shots), showing that the test-MAE remains within ∼ 0.06 of the infinite-shot value down to 4096 shots on the regression task, with no systematic degradation at lower shot counts, indicating moderate shot-noise robustness. Hardware (depolarizing / decoherence) noise was not modelled and is left to future work. These contributions establish VQKAN as a promising tool for advancing quantum machine learning and optimization techniques on tasks where edge-wise function approximations are natural.\u0000</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148751416","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":"Improving the performance of reference-frame-independent quantum key distribution with two-way classical post-processing","authors":"Da-Wei Li,&nbsp;Li Zhang,&nbsp;Wen-Hao Li,&nbsp;Xiao-Lei Jiang,&nbsp;Zhi-Lin Xie,&nbsp;Huan Li,&nbsp;Hong-Yan Song,&nbsp;Yun Liu,&nbsp;Chun Zhou","doi":"10.1007/s11128-026-05308-9","DOIUrl":"10.1007/s11128-026-05308-9","url":null,"abstract":"<div><p>Reference-frame-independent quantum key distribution (RFI-QKD) has the advantage of tolerating the slow varied reference frame. Two remote communication parties can share secret keys in the case of unknown and drifted reference frames. However, in the practical QKD system, the drift of reference frames will inevitably compromise the performance of the QKD system, resulting in the reduction of the secret key rate and transmission distance. In this paper, we attempt to improve the performance of RFI-QKD and RFI measurement-device-independent QKD (RFI MDI-QKD) based on the two-way local operations and classical communications (TW-LOCC) classical post-processing method. We focus on the iterative B-step-optimized TW-LOCC due to its immediate experimental feasibility. The simulation results show that the TW-LOCC method can significantly improve the transmission distance and secret key rate of RFI-QKD and RFI MDI-QKD by optimizing the number of executions <i>B</i> steps, and the maximum safe transmission distance is increased by 92 and 60 km, respectively. Our work provides a new idea for the post-processing of RFI-QKD protocols and further enhances the practicability and robustness of RFI-QKD.\u0000</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148751417","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":"Enhancing the robustness of two-qutrit quantum correlations using switch of correlated quantum channels","authors":"Soundarya Pran Chaliha,&nbsp;Rajiuddink Sk,&nbsp;Abdul Q. Batin,&nbsp;Prasanta K. Panigrahi","doi":"10.1007/s11128-026-05301-2","DOIUrl":"10.1007/s11128-026-05301-2","url":null,"abstract":"<div><p>Preserving quantum correlations in noisy environments is fundamental for advancing quantum technologies. We investigate the interplay between channel memory and indefinite causal order in protecting bipartite correlations—coherence, entanglement, and discord—between two qutrits. Our analysis covers amplitude damping channels with <i>V</i>-type and <span>(Lambda )</span>-type transitions, as well as trit flip, phase flip, and depolarizing channels. We show that memory effects in correlated channels not only delay entanglement sudden death but also enhance the resilience of quantum correlations against decoherence. Strikingly, the quantum switch of amplitude damping and bit-flip channels offers a significant advantage over their memoryless counterparts, demonstrating that indefinite causal order can amplify the benefits of channel memory. Fidelity analysis further confirms that correlations in two-qutrit states remain substantially more robust in correlated channels across all scenarios studied. These findings highlight the potential of combining channel memory and causal indefiniteness as powerful resources for reliable quantum communication and information processing.</p></div>","PeriodicalId":746,"journal":{"name":"Quantum Information Processing","volume":"25 9","pages":""},"PeriodicalIF":2.2,"publicationDate":"2026-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148695258","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}