IEEE Transactions on Quantum Engineering最新文献

{"title":"InterQnet: A Heterogeneous Full-Stack Approach to Co-Designing Scalable Quantum Networks","authors":"Joaquin Chung;Daniel Dilley;Ely Eastman;Alvin Gonzales;Kara Hokenstad;Md Shariful Islam;Varun Jorapur;Joseph Petrullo;Andy C. Y. Li;Bikun Li;Vasileios Niaouris;Anirudh Ramesh;Ansh Singal;Zeyu Ye;Caitao Zhan;Michael Bishof;Eric Chitambar;Jacob P. Covey;Alan Dibos;Xu Han;Liang Jiang;Prem Kumar;Jeffrey Larson;Zain H. Saleem;Rajkumar Kettimuthu","doi":"10.1109/TQE.2026.3674887","DOIUrl":"https://doi.org/10.1109/TQE.2026.3674887","url":null,"abstract":"Quantum communications have progressed significantly, moving from a theoretical concept to small-scale experiments to recent metropolitan-scale demonstrations. As the technology matures, it is expected to revolutionize quantum computing in much the same way that classical networks revolutionized classical computing. Quantum communications will also enable breakthroughs in quantum sensing, metrology, and other areas. However, scalability has emerged as a major challenge, particularly in terms of the number and heterogeneity of nodes, the distances between nodes, the diversity of applications, and the scale of user demand. This article describes InterQnet, a multidisciplinary project that advances scalable quantum communications through a comprehensive approach that improves devices, error handling, and network architecture. InterQnet has a two-pronged strategy to address scalability challenges: InterQnet-Achieve focuses on practical realizations of heterogeneous quantum networks by building and then integrating first-generation quantum repeaters with error mitigation schemes and centralized automated network control systems. The resulting system will enable quantum communications between two heterogeneous quantum platforms through a third type of platform operating as a repeater node. InterQnet-Scale focuses on a systems study of architectural choices for scalable quantum networks by developing forward-looking models of quantum network devices, advanced error correction schemes, and entanglement protocols. Here, we report our current progress toward achieving our scalability goals.","PeriodicalId":100644,"journal":{"name":"IEEE Transactions on Quantum Engineering","volume":"7 ","pages":"1-21"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11440135","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147796047","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":"Advanced Quantum Annealing for the Biobjective Traveling Thief Problem: An $varepsilon$-Constraint-Based Approach","authors":"Nguyen Hoang Viet;Nguyen Xuan Tung;Trinh Van Chien;Won-Joo Hwang","doi":"10.1109/TQE.2026.3674551","DOIUrl":"https://doi.org/10.1109/TQE.2026.3674551","url":null,"abstract":"This article addresses the biobjective traveling thief problem (BI-TTP), a challenging multiobjective optimization problem that requires the simultaneous optimization of travel cost and item profit. Conventional methods for the BI-TTP often face severe scalability issues due to the complex interdependence between routing and packing decisions, as well as the inherent complexity and large problem size. These difficulties render classical computing approaches increasingly inapplicable. To tackle this, we propose an advanced hybrid approach that combines quantum annealing (QA) with the <inline-formula><tex-math>$varepsilon$</tex-math></inline-formula>-constraint method. Specifically, we reformulate the biobjective problem into a single-objective formulation by restricting the second objective through adjustable <inline-formula><tex-math>$varepsilon$</tex-math></inline-formula>-levels, determined within established upper and lower bounds. The resulting subproblem involves a sum of fractional terms, which is reformulated with auxiliary variables into an equivalent form. Subsequently, the equivalent formulation is transformed into a quadratic unconstrained binary optimization model, enabling direct solution via a QA solver. The solutions obtained from the quantum annealer are subsequently refined using a tailored heuristic procedure to further enhance the overall performance. By leveraging the flexibility in selecting <inline-formula><tex-math>$varepsilon$</tex-math></inline-formula> parameters, our approach effectively captures a broad Pareto front, enhancing solution diversity. Experimental results on benchmark instances demonstrate that the proposed method effectively balances two objectives and outperforms baseline approaches in time efficiency.","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=11435401","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148480115","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":"Quantum Compressed Sensing Tomographic Reconstruction Algorithm","authors":"Arim Ryou;Kiwoong Kim;Kyungtaek Jun","doi":"10.1109/TQE.2026.3681530","DOIUrl":"https://doi.org/10.1109/TQE.2026.3681530","url":null,"abstract":"Computed tomography (CT) is a nondestructive technique for observing internal images and has proven highly valuable in medical diagnostics. Recent advances in quantum computing have begun to influence tomographic reconstruction techniques. The quantum tomographic reconstruction algorithm is less affected by artifacts or noise than classical algorithms by using the square function of the difference between pixels obtained by projecting CT images in quantum superposition states and pixels obtained from experimental data. In particular, by using quantum linear systems, a fast quadratic unconstrained binary optimization (QUBO) model formulation for quantum tomographic reconstruction is possible. In this article, we formulate the QUBO model for quantum compressed sensing tomographic reconstruction, which is a linear combination of the QUBO model for quantum tomographic reconstruction and the QUBO model for total variation in quantum superposition-state CT images. In our experiments, we used sinograms obtained by using the Radon transform of Shepp–Logan images and body CT images. We evaluate the performance of the new algorithm by reconstructing CT images using a hybrid solver with the QUBO model computed from each sinogram. The new algorithm was able to obtain a solution within five projection images for <inline-formula><tex-math>$30 times 30$</tex-math></inline-formula> image samples and within six projection images for <inline-formula><tex-math>$60 times 60$</tex-math></inline-formula> image samples, reconstructing error-free CT images. We anticipate that quantum compressed sensing tomographic reconstruction algorithms could significantly reduce the total radiation dose when quantum computing performance advances.","PeriodicalId":100644,"journal":{"name":"IEEE Transactions on Quantum Engineering","volume":"7 ","pages":"1-9"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11475415","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148480111","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":"Unified and Generalized Approach to Entanglement-Assisted Quantum Error Correction","authors":"Priya J. Nadkarni;Serge Adonsou;Guillaume Dauphinais;David W. Kribs;Michael Vasmer","doi":"10.1109/TQE.2026.3692012","DOIUrl":"https://doi.org/10.1109/TQE.2026.3692012","url":null,"abstract":"We introduce a framework for entanglement-assisted quantum error correcting codes that unifies the three original frameworks for such codes called entanglement-assisted quantum error correction, entanglement-assisted operator quantum error correction, and entanglement-assisted classical enhanced quantum error correction under a single umbrella. As a consequence, new types of entanglement-assisted codes are identified and constructed. The unification is arrived at by viewing entanglement-assisted codes from the operator algebra quantum error correction perspective, and it is built upon a recently established extension of the stabilizer formalism to that setting. We call the framework entanglement-assisted operator algebra quantum error correction, and we prove a general error correction theorem for such codes, derived from the algebraic perspective, that generalizes each of the earlier results and also applies to the new types of codes. This motivates a natural notion of distance for such codes, and we derive a number of distance results for subclasses of the codes. We show precisely how the original classically enhanced codes form a proper subclass of the new entanglement-assisted subspace codes defined by the general framework. We identify and construct new classes of entanglement-assisted subsystem codes and entanglement-assisted hybrid classical-quantum codes that are found outside of the earlier approaches, and we include a quantum communication application.","PeriodicalId":100644,"journal":{"name":"IEEE Transactions on Quantum Engineering","volume":"7 ","pages":"2101132-2101132"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11515068","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148480732","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":"QCHFT: Quantum Cross-Hybrid Fine-Tuning for LLMs","authors":"Yuanjie Li;Kyungmin Lim;Jinsuk Baek;Minho Jo","doi":"10.1109/TQE.2026.3690560","DOIUrl":"https://doi.org/10.1109/TQE.2026.3690560","url":null,"abstract":"When full-parameter updates are impractical for large language models (LLMs), parameter-efficient fine-tuning (PEFT) is commonly employed to reduce the number of trainable parameters. Classical PEFT methods, such as low-rank adaptation (LoRA), are limited to linear transformations and may not capture complex high-order feature interactions under stringent parameter constraints. In contrast, parameterized quantum circuits (PQCs) provide high-order expressivity per qubit rotation degree of freedom. Inspired by PQCs, in this article, we propose quantum cross-hybrid fine-tuning (QCHFT), a suite of four PQC-augmented adapters: matrix product state PQC, alternating and hierarchical pairwise contraction PQC, and LinearA–Quantum–LinearB PQC. To evaluate our QCHFT adapters, we conduct experiments on a public multitier Internet of Things (IoT) resource-allocation task that serves as a challenging benchmark with intricate cross-tier interactions data and limited parameter budgets. We conduct experiments on a multitier IoT resource-allocation task across five causal LLM backbones scaling from 125 M to 2B parameters, including Mamba2, GPT-Neo, Pythia, Llama-3.2, and Qwen-3.5. Our results demonstrate that QCHFT consistently enhances performance compared to both standard LoRA. On Mamba2-130M, the APC–PQC variant improves accuracy from 67.33% (LoRA) to 72.66%. These findings suggest that the high expressivity of quantum entanglement can be practically harnessed through shallow circuits, providing a superior parameter-efficient pathway for adapting foundation models to complex high-feature tasks.","PeriodicalId":100644,"journal":{"name":"IEEE Transactions on Quantum Engineering","volume":"7 ","pages":"1-21"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11506237","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148481325","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":"Equivariant Quantum Approximate Optimization Algorithm","authors":"Boris Tsvelikhovskiy;Ilya Safro;Yuri Alexeev","doi":"10.1109/TQE.2026.3654930","DOIUrl":"https://doi.org/10.1109/TQE.2026.3654930","url":null,"abstract":"Constructing effective mixer Hamiltonians is essential for enhancing the performance of the quantum approximate optimization algorithm (QAOA) in solving combinatorial optimization problems. In this work, we develop a systematic methodology for designing QAOA mixers that align with the symmetries of the classical objective function, with the goal of achieving values (mean, median, and minimum over multiple runs) that are closer to the true optimum. Our main idea is to design QAOA operators that are explicitly adapted to the action of symmetry groups on the Hilbert space. We focus on subgroups of the symmetric group <inline-formula><tex-math>$ S_{d}$</tex-math></inline-formula>, where <inline-formula><tex-math>$ d = 2^ell$</tex-math></inline-formula>, to ensure compatibility with qudit-based quantum architectures. In particular, we construct QAOA mixers invariant under the full symmetric group <inline-formula><tex-math>$ S_{d}$</tex-math></inline-formula> as well as its cyclic subgroup <inline-formula><tex-math>$ mathbb {Z}_{d} subset S_{d}$</tex-math></inline-formula>. These constructions are natural in that they respect the decomposition of the Hilbert space into isotypic components under the symmetry group action. Notably, to the best of the authors’ knowledge, the QAOA algorithm based on the <inline-formula><tex-math>$ mathbb {Z}_{d}$</tex-math></inline-formula>-invariant mixer provides the first example of a QAOA protocol whose dynamics (up to final measurement) are confined entirely within a nontrivial irreducible representation of a symmetry group of the objective function. Although our work does not investigate the benefits of exploiting such subspaces as computational resources, we think that the very realization of a variational algorithm whose evolution is restricted to a nontrivial symmetry-adapted subspace is of fundamental conceptual interest. We provide closed-form expressions for these mixers, together with explicit quantum circuit implementations. To empirically evaluate our approach, we compare QAOA variants employing the standard mixer <inline-formula><tex-math>$B = sum X_{i}$</tex-math></inline-formula> with those using our proposed Hamiltonians <inline-formula><tex-math>$H_{M}$</tex-math></inline-formula> and <inline-formula><tex-math>$H_chi$</tex-math></inline-formula> on edge coloring and graph partitioning problems. Across multiple graph instances, our symmetry-adapted mixers consistently yield objective values closer to the optimum, demonstrating statistically significant improvements over classical baselines.","PeriodicalId":100644,"journal":{"name":"IEEE Transactions on Quantum Engineering","volume":"7 ","pages":"1-13"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11355846","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148481594","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":"Quantum Squeeze-and-Excitation Networks: Harnessing Quantum Noise for Robust Attention Mechanisms in Hybrid Architectures","authors":"Yifeng Peng;Xinyi Li;Ying Wang","doi":"10.1109/TQE.2026.3707472","DOIUrl":"https://doi.org/10.1109/TQE.2026.3707472","url":null,"abstract":"By simulating the selective focus characteristics of human visual attention, the attention network has greatly improved the model's ability to capture key features, promoting significant progress in natural language processing, computer vision, and other fields. As a typical attention mechanism, the squeeze-and-excitation (SE) module finely adjusts the feature representation of the neural network by reweighting the features between channels, further enhancing the performance and generalization ability of the model. In this article, we introduce quantum squeeze-and-excitation (QSE) networks, a pioneering approach that enhances the excitation module of classical SE networks using quantum computing. Our method simplifies the model's complexity and boosts performance by employing quantum amplitude coding for data encoding, significantly reducing the parameter count of fully connected layers in classical SE module. To optimize the quantum circuits within the QSE module, we explore five different controlled quantum-NOT (CNOT) gate topologies: circular, linear, star, tree, and mesh. Experimental results show that, after 100 training rounds, the accuracy of our proposed linear topology-based QSE ResNet-18 on the CIFAR-10 dataset reached 85.00% in no noise case, while the classical SE ResNet-18 was only 82.20%. Contrary to the common perception of noise as a disruptive and unavoidable challenge, we demonstrate that, through specific topology structures and a hybrid quantum-classical QSE design, quantum noise does not need to be deliberately avoided. Instead, we leverage quantum noise to enhance the robustness of QSE networks and mitigate the local optima trapping problem caused by circuit redundancy by four quantum noise models—amplitude damping, depolarizing, phase-flip, and bit-flip noise. Experimental results show that under four noise models, the QSE accuracy of the five different topological results we proposed can reach a performance of more than 85.00%. The inevitable quantum noise inherently serves as an advantage in the proposed QSE.","PeriodicalId":100644,"journal":{"name":"IEEE Transactions on Quantum Engineering","volume":"7 ","pages":"3104427-3104427"},"PeriodicalIF":4.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11578346","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148747400","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":"Cut&Shoot: Distributed Execution of Quantum Circuit Fragments","authors":"Giuseppe Bisicchia;Alessandro Bocci;Jose Garcia-Alonso;Juan M. Murillo;Antonio Brogi","doi":"10.1109/TQE.2026.3675340","DOIUrl":"https://doi.org/10.1109/TQE.2026.3675340","url":null,"abstract":"Quantum computing is progressing at a rapid pace, although still constrained by the limitations of noisy intermediate-scale quantum (NISQ) devices, such as restricted qubit counts and high susceptibility to noise. To address these constraints, researchers have begun adapting classical software engineering principles to the quantum realm, giving rise to the field of quantum software engineering. Within this context, techniques, such as circuit-cutting and shotwise distribution, have emerged as promising approaches to divide quantum circuits into smaller fragments and to improve the scalability and reliability of quantum computations. In this article, we present our Cut&Shoot pipeline, which supports the cutting of quantum circuits and the flexible distribution of their shots across multiple quantum processing units (QPUs), in a unified execution strategy. We compare different policies to determine the number of shots for which each fragment should be executed on each QPU. Through 107 000+ experiments on simulated NISQ devices, we assess how circuit size, shot allocation, and QPU availability affect execution times and error rates. Our findings indicate that combining circuit-cutting and shotwise distribution provides a useful tradeoff of execution times and error rates, while featuring high-qubit quantum computations as well as increased resilience and adaptiveness.","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=11477850","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147696681","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":"Measurement-Informed Safe Reinforcement Learning for Quantum Battery Charging via Harmonic-Syndrome Diagnostics and BMS Constraints","authors":"Sangkeum Lee;Beomdo Park;Junseong Park;Hyeonseok Jang;Hoon Jeong;Taewook Heo","doi":"10.1109/TQE.2026.3670136","DOIUrl":"https://doi.org/10.1109/TQE.2026.3670136","url":null,"abstract":"Quantum batteries promise ultrafast energy storage but are highly sensitive to noise, drift, and hardware constraints, making safe high-performance charging a central challenge for noisy intermediate-scale quantum devices. We propose a measurement-informed safe control framework that couples harmonic-spectrum-based syndrome diagnostics—<inline-formula><tex-math>$H_{2}/H_{1}$</tex-math></inline-formula>, <inline-formula><tex-math>$H_{3}/H_{1}$</tex-math></inline-formula>, and frequency drift—with a battery management system (BMS)-constrained curriculum reinforcement learning (RL) policy. Spectral features are compressed into a three-level syndrome code (<inline-formula><tex-math>$sin lbrace 0,1,2rbrace$</tex-math></inline-formula>) that serves as a real-time hardware risk proxy for the controller. Our digital-twin simulator incorporates <inline-formula><tex-math>$T_{1}/T_phi$</tex-math></inline-formula> relaxation, crosstalk, collective effects, and terminal-voltage dynamics, while safety risks are explicitly encoded as BMS-related penalties (state-of-health, voltage limits, and high-risk operation ratio) in the RL reward. Across staged curricula of increasing system complexity, the learned policy empirically traces a strictly improved Pareto frontier between final ergotropy and high-risk ratio compared to baseline and threshold-grid control strategies, with gains confirmed by multiseed statistical confidence intervals. To support near-term deployment, we position the current work as a digital-twin stage and outline a concrete simulation-to-real protocol: fix receiver-operating-characteristic-calibrated thresholds, retune <inline-formula><tex-math>$(tau ^{w},tau ^{h})$</tex-math></inline-formula> on a small hardware calibration split, and validate a one-step voltage shield. We further demonstrate the framework on a benchtop transmon setup with <inline-formula><tex-math>$N=1$</tex-math></inline-formula>–2, reporting shield trigger/violation rates, sim-to-real drift of spectral features Kullback–Leibler divergence/earth mover's distance (KL)/(EMD), and an end-to-end latency within 20 <inline-formula><tex-math>$mathrm{mu }$</tex-math></inline-formula> <inline-formula><tex-math>$mathrm{s}$</tex-math></inline-formula>, indicating that harmonic-syndrome-informed safe RL is a viable route toward practical quantum battery charging control.","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=11419848","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147665339","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":"Efficient Optical Coupling of Color Center Ensembles in Diamond","authors":"Yachel Ben-Shalom;Amir Hen;Nir Bar-Gill","doi":"10.1109/TQE.2026.3689570","DOIUrl":"https://doi.org/10.1109/TQE.2026.3689570","url":null,"abstract":"Nitrogen-vacancy (NV) centers in diamond have emerged as a leading platform for quantum sensing, particularly in magnetic field detection. Efficient interrogation of large NV ensembles is crucial for achieving high sensitivity. This article presents a comprehensive analysis of the optical efficiencies that govern the performance of NV-based sensing systems, focusing on excitation, conversion, and collection, leading to a novel collection design improving upon state-of-the-art results. To optimize various excitation schemes, we developed numerical tools capable of accurately calculating excitation efficiencies for arbitrary power density distributions. Using these tools, we investigated several techniques, including reflective coatings and corner excitation, and achieved excitation efficiencies exceeding 0.7, compared to the <inline-formula><tex-math>$sim 0.4$</tex-math></inline-formula> efficiency achieved by standard methods. We also measured the conversion efficiency of NV centers, quantifying the ratio of absorbed green excitation versus fluorescence, in various diamond samples. This value is usually missing in the literature, and therefore important to quantify in different regimes. We obtained a value of <inline-formula><tex-math>$eta _{v}=0.22 pm 0.03$</tex-math></inline-formula>, which is consistent with theoretical expectations. Furthermore, we designed and experimentally validated a novel compound trapezoid collector (CTC) for enhanced photon collection. The CTC offers performance comparable to that of traditional compound parabolic collectors, but with a significantly smaller form factor and simplified manufacturing. Our prototype CTC achieved a collection efficiency of 0.33, with the potential to reach approximately <inline-formula><tex-math>$sim 0.8$</tex-math></inline-formula>. This work provides insights into optimizing the optical efficiencies of NV-based sensing systems and contributes to the development of practical devices.","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=11505048","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148171696","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}