IEEE Transactions on Quantum Engineering -

Integrated Superconducting High-Q Seamless Cavity for Quantum Memory and Qubit Readout Applications

August 31, 2026Mohamed F. Hagag, Kareem H. El-Gendy, Bashar Zyoud, Thomas R. Jones, Karim Seddik, Dimitrios PeroulisEarly Access, Open AccessArchitecture, Couplings, Dielectrics, Filtering, Frequency, Joining processes, Memory, Qubit, Resonators, Surfaces

Abstract: This work presents a novel micromachined, seamless sapphire–silicon hybrid evanescent-mode cavity architecture incorporating selectively engineered coupling channels and flux-tunable external coupling via a SQUID. The proposed design enables two simulated operating states within a single device: an ultra–high Q memory configuration and a high-speed readout configuration with intrinsic Purcell filtering, which is expected to […]

RuleSet Generation Framework for Application Layer Integration in Quantum Internet

August 31, 2026Rei Kawano, Shin Nishio, Hideaki Kawaguchi, Shota Nagayama, Takahiko SatohEarly Access, Open AccessInternet, Memory, Modeling, Protocols, Qubit, Repeaters, Schedules, Scheduling, Servers, Timing

Abstract: Layered architectures for the Quantum Internet have been proposed, inspired by that of the classical Internet, which has demonstrated high maintainability even in large-scale systems. While lower layers in the Quantum Internet, such as entanglement generation and distribution, have been extensively studied, the application layer — responsible for translating user requests into executable quantum-network […]

Interconnecting Regional QKD Networks: Hybrid Key Delivery Across Quantum Domains

August 31, 2026David Barral, Aitor Brazaola-Vicario, Diego Cifrián, Natalia Costas, Gonzalo Blázquez, Ana Fernández-Vilas, Iago Fernández Llovo, Pedro Otero, Pablo Pío Rejo, Alejandra Ruiz, Juan Villasuso, Manuel Fernández-VeigaEarly Access, Open AccessArchitecture, Computer architecture, Databases, ETSI, Joining processes, Management, Quantum key distribution, Relays, Security, Timing

Abstract: QKD technology is being increasingly adopted inside the network core for protecting information transport against any form of computational attacks. However, the use of QKD for wide-area internetworking is still challenging and costly, due to its strong trust assumptions and the low achievable key rates in long QKD links. This paper presents a standards-driven […]

Field Demonstration of a Passive Phase and Polarization Stabilization Architecture for Sagnac Twin-Field QKD

August 28, 2026Martin Clason, Christiano M. S. do Nascimento, Felipe Calliari, Joakim Argillander, Guilherme B. Xavier, Guilherme P. TemporãoEarly Access, Open AccessFrequency modulation, Generators, Interference, Joining processes, Optical fibers, Polarization, Quantum communication, Quantum key distribution, Textile fibers, Timing

Abstract: Twin-field quantum key distribution (TF-QKD) relies on first-order interference between coherent optical fields combined at an intermediate station, which requires simultaneous phase and polarization stabilization. We present a Sagnac-like interferometric architecture arranged in a hybrid star–bus network topology that enables any-to-any connectivity while providing passive stabilization of phase and polarization fluctuations for multiple wavelengths. […]

Efficiently Architecting VQAs: Expressibility–Trainability–Resources Pareto-Optimality

August 24, 2026Rodrigo M. Sanz, Andreu Anglés-Castillo, Eduard Alarcón, Carmen G. AlmudéverEarly Access, Open AccessAlgorithms, Circuits, Cost function, Costing, Costs, Design methodology, Measurement, Modeling, Optimization, Qubit

Abstract: Ansatz selection is a key factor in the performance of variational quantum algorithms (VQAs). While much of the state-of-the-art still relies on heuristic choices, an inadequate circuit structure can compromise both the expressive power and the trainability of the resulting model. Recent results have also established theoretical connections between expressibility and the onset of […]

Dissipative Feedback and Hybrid Lyapunov-Reinforcement Learning Control for NV-Center Quantum Sensing

August 17, 2026Yuxuan Zhao, Xiaofeng Jiang, Tianxiang Xiong, Sen Kuang, Jian YangEarly Access, Open AccessDynamics, Feedback, Learning (artificial intelligence), Modeling, Optimization, Quantum sensing, Reinforcement learning, Sensitivity, Timing, Training

Abstract: Practical NV-center magnetometry requires both accurate modeling of open quantum dynamics and robust control under environmental drift. However, commonly used perturbative descriptions inadequately capture dissipative processes, while existing control strategies remain individually limited: open-loop protocols cannot adapt to unknown frequency variations, Lyapunov feedback typically converges only to a neighborhood of the optimal sensing state, […]

Entanglement Distribution and Teleportation in Assisted and Scalable Quantum Access Networks

August 11, 2026Amir Mohammad Yaghoobianzadeh, Jawad A. SalehiEarly Access, Open AccessDetectors, Joining processes, Matrices, Modeling, Passive optical networks, Probability, Protocols, Reviews, Teleportation, Textile fibers

Abstract: We have investigated the entanglement distribution and quantum teleportation in quantum passive optical networks (QPONs), where an entangled state is distributed between the central node and multiple end users through lossy fibers and passive optical splitter/combiner. The entanglement degradation is quantified using logarithmic negativity, and teleportation fidelity both in non-assisted and assisted strategies. We […]

Network-Based Quantum Computing: an Efficient Design Framework for Many-small-node Distributed Fault-Tolerant Quantum Computing

August 10, 2026Soshun Naito, Yasunari Suzuki, Yuuki TokunagaEarly Access, Open AccessAlgorithms, Circuits, Design methodology, Joining processes, Optimization, Ports (computers), Quantum computing, Qubit, Switches, Timing

Abstract: In fault-tolerant quantum computing, a large number of physical qubits are required to construct a single logical qubit, and a single quantum node may be able to hold only a small number of logical qubits. In such a case, the idea of distributed fault-tolerant quantum computing (DFTQC) is important to demonstrate large-scale quantum computation […]

Clifford Manipulations of Stabilizer States – Application to Linear Optical Qubits

August 6, 2026Ashlesha Patil, Saikat GuhaEarly Access, Open AccessCircuits, Detectors, Encoding, Hilbert space, Measurement, Polarization, Probability, Quantum circuit, Qubit, Rails

Abstract: The single-photon dual-rail qubit is popular for photonic quantum computing and communications, both due to gates being realizable with linear optics (LO) and photon detection, as well as easy interfaces with matter quantum memories. Two-qubit operations, i.e., two-qubit gates followed by the measurement of one (Type-I fusion) or both (Type-II fusion) qubits, are, however, […]

Rydberg Atom Electric Field Sensors as Linear Time-invariant Systems

August 6, 2026Neel Malvania, Garry Jacyna, Bonnie L. Schmittberger Marlow, Zachary N. Hardesty-Shaw, Kathryn L. Nicolich, Kelly M. Backes, Jamie L. MacLennan, Charlie T. FancherEarly Access, Open AccessElectric fields, Frequency, Image sensors, Matrices, Modeling, Radio frequency, Rydberg atoms, Steady-state, Timing, Transfer functions

Abstract: Over the past decade, Rydberg atom electric field sensors have been under investigation as potential alternatives or complements to conventional antenna-based receivers for select applications in RF communications, remote sensing, and precision metrology. To understand the potential utility of these devices for various use cases, it is crucial to develop models that accurately predict […]