Uncategorized Archives - IEEE Transactions on Quantum Engineering

Exploration of Design Alternatives for Reducing Idle Time in Shor’s Algorithm: A Study on Monolithic and Distributed Quantum Systems

September 17, 2025Moritz Schmidt Abhoy Kole Leon Wichette Rolf Drechsler Frank Kirchner Elie MounzerQuantum Computing, UncategorizedArithmetic, Computer architecture, Hardware, Logic gates, Optimization, Quantum circuit, Quantum computing, Qubit, Registers, Standards

Abstract: Shor’s algorithm is one of the most prominent quantum algorithms, yet finding efficient implementations remains an active research challenge. While many approaches focus on low-level modular arithmetic optimizations, a broader perspective can provide additional opportunities for improvement. By adopting a midlevel abstraction, we analyze the algorithm as a sequence of computational tasks, enabling systematic […]

DT-QFL: Dual-Timeline Quantum Federated Learning With Time-Symmetric Updates, Temporal Memory Kernels, and Reversed Gradient Dynamics

September 9, 2025Koffka Khan Khouler KhanQuantum Computing, UncategorizedAdaptation models, Computational modeling, Data models, Federated Learning, Kernel, Neural networks, Quantum computing, Robustness, Servers, Training

Abstract: Federated learning has emerged as a powerful paradigm for decentralized model training, ensuring privacy preservation by allowing clients to collaboratively learn a shared model without exchanging raw data. Quantum federated learning (QFL) extends this approach by leveraging quantum computing to enhance computational efficiency and security. However, existing QFL frameworks face challenges in handling temporal […]

Improved Belief Propagation Decoding Algorithms for Surface Codes

June 6, 2025Jiahan Chen; Zhengzhong Yi; Zhipeng Liang; Xuan WangUncategorizedAccuracy, Belief propagation, Codes, Complexity theory, Error correction, Maximum likelihood decoding, Noise, Qubit, Silicon, Time complexity

Abstract: Quantum error correction is crucial for universal fault-tolerant quantum computing. Highly accurate and low-time-complexity decoding algorithms play an indispensable role in ensuring quantum error correction works effectively. Among existing decoding algorithms, belief propagation (BP) is notable for its nearly linear time complexity and general applicability to stabilizer codes. However, BP’s decoding accuracy without postprocessing […]

Memory-Optimized Cubic Splines for High-Fidelity Quantum Operations

May 28, 2025Jan Ole Ernst; Jan Snoeijs; Mitchell Peaks; Jochen WolfEnabling Technologies, UncategorizedCurve fitting, Field programmable gate arrays, Fitting, Hardware, Logic gates, Memory management, Polynomials, Quantum computing, Qubit, Splines (mathematics)

Abstract: Radio frequency pulses are preponderant for the control of quantum bits and the execution of operations in quantum computers. The ability to fine-tune key pulse parameters, such as time-dependent amplitude, phase, and frequency, is essential to achieve maximal gate fidelity and mitigate errors. As systems increase in scale, a larger proportion of the control […]

Q-Gen: A Parameterized Quantum Circuit Generator

May 20, 2025Yikai Mao; Shaswot Shresthamali; Masaaki KondoQuantum Software, UncategorizedComplexity theory, Computational modeling, Generators, Integrated circuit modeling, Logic gates, Quantum algorithm, Quantum circuit, Quantum computing, Quantum mechanics, Qubit

Abstract: Unlike most classical algorithms that take an input and give the solution directly as an output, quantum algorithms produce a quantum circuit that works as an indirect solution to computationally hard problems. In the full quantum computing workflow, most data processing remains in the classical domain except for running the quantum circuit in the […]

Analysis of Parameterized Quantum Circuits: On the Connection Between Expressibility and Types of Quantum Gates

May 19, 2025Yu Liu; Kazuya Kaneko; Kentaro Baba; Jumpei Koyama; Koichi Kimura; Naoyuki TakedaQuantum Computing, UncategorizedAccuracy, Additives, Computational modeling, Integrated circuit modeling, Kernel, Logic gates, Predictive models, Quantum circuit, Qubit, Topology

Abstract: Expressibility is a crucial factor of a parameterized quantum circuit (PQC). In the context of variational-quantum-algorithm-based quantum machine learning (QML), a QML model composed of a highly expressible PQC and a sufficient number of qubits is theoretically capable of approximating any arbitrary continuous function. While much research has explored the relationship between expressibility and […]

Reducing Quantum Error Correction Overhead With Versatile Flag-Sharing Syndrome Extraction Circuits

May 13, 2025Pei-Hao Liou; Ching-Yi LaiQuantum Computing, UncategorizedCircuits, Codes, Decoding, Error correction, Fault tolerance, Fault tolerant systems, Logic gates, Measurement uncertainty, Quantum computing, Qubit

Abstract: Given that quantum error correction processes are unreliable, an efficient error syndrome extraction circuit should use fewer ancillary qubits, quantum gates, and measurements while maintaining low circuit depth, to minimize the circuit area, roughly defined as the product of circuit depth and the number of physical qubits. We propose to design parallel flagged syndrome […]

Quantum Wavelength-Division Multiplexing and Multiple-Access Communication Systems and Networks: Advanced Applications

May 12, 2025Marzieh Bathaee; Mohammad Rezai; Jawad A. SalehiQuantum Networking & Communications, UncategorizedCommunication systems, Mathematical models, Network topology, Optical fiber amplifiers, Optical fiber networks, Quantum networks, Receivers, Stars, Topology, WDM networks

Abstract: A cost-effective global quantum Internet may be developed using the existing communication infrastructure. This article examines the quantum version of three conventional wavelength-division-multiplexing and multiple-access (WDM) communication systems and networks. They are Lambdanet-based broadcast WDM networks, quantum routers based on a waveguide grating router, and fiber-to-the-quantum nodes that are fed by two opposing and […]

Three-Party Controlled Authentication Semiquantum Key Agreement Protocol for Online Joint Consultation

May 12, 2025XiYuan Liang; YeFeng He; YiChi Zhang; JiaQiang FanQuantum Information, UncategorizedAuthorizing identity, cluster states, quantum cryptography, qubit efficiency, semiquantum key agreement (SQKA)

Abstract: In Wise Information Technology of Medicine, to ensure both confidentiality and integrity of the data created during online joint consultations, and to solve the problem that ordinary users cannot afford expensive quantum devices and are vulnerable to man-in-the-middle attacks during communication, this article proposes a three-party controlled authentication semiquantum key agreement protocol, leveraging the […]

On Quantum Natural Policy Gradients

June 24, 2024André Sequeira, Luis Paulo Santos, Luis Soares Barbosa,Regular, UncategorizedBasic Conditions, Deep Reinforcement Learning, Estimation Error, Expected Value, Fisher Information, Fisher Information Matrix, Gradient Ascent, Gradient Update, Infidelity, Less Than Or Equal, Markov Decision Process, Matrix Inequalities, Natural Gradient, Normal Vector, Optimal Policy, Policy Gradient, Policy Gradient Method, Policy Parameters, Policy Space, Positive Semidefinite Matrix, Preconditioning, Projector, Proximal Policy Optimization, Quantum circuit, Quantum Measurement, Quantum state, Reward Function, Square Root, Standard Gradient, State Space

This article delves into the role of the quantum Fisher information matrix (FIM) in enhancing the performance of parameterized quantum circuit (PQC)-based reinforcement learning agents. While previous studies have highlighted the effectiveness of PQC-based policies preconditioned with the quantum FIM in contextual bandits, its impact in broader reinforcement learning contexts, such as Markov decision processes, […]