Qubit 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 […]

End-to-End Workflow for Machine-Learning-Based Qubit Readout With QICK and hls4ml

September 11, 2025Giuseppe Di Guglielmo Botao Du Javier Campos Alexandra Boltasseva Akash Dixit Farah FahimEnabling TechnologiesArtificial neural networks, Field programmable gate arrays, Hardware, Microprogramming, Microwave amplifiers, Microwave circuits, Qubit, Resonant frequency, Software, Table lookup

Abstract: In this article, we present an end-to-end workflow for superconducting qubit readout that embeds codesigned neural networks into the quantum instrumentation control kit (QICK). Capitalizing on the custom firmware and software of the QICK platform, which is built on Xilinx radiofrequency system-on-chip field-programmable gate arrays (FPGAs), we aim to leverage machine learning (ML) to […]

Benchmarking the Ability of a Controller to Execute Quantum Error Corrected Non-Clifford Circuits

September 9, 2025Yaniv Kurman Lior Ella Ramon Szmuk Oded Wertheim Benedikt Dorschner Sam StanwyckEnabling TechnologiesBenchmark testing, Circuits, Codes, Decoding, Fault tolerance, Fault tolerant systems, Logic gates, Measurement uncertainty, Quantum computing, Qubit

Abstract: Reaching fault-tolerant quantum computation relies on the successful implementation of non-Clifford circuits with quantum error correction (QEC). In QEC, quantum gates and measurements encode quantum information into an error-protected Hilbert space, while classical processing decodes the measurements into logical errors. QEC non-Clifford gates pose the greatest computation challenge from the classical controller’s perspective, as […]

Generalized Quantum-Assisted Digital Signature

August 4, 2025Alberto Tarable; Rudi Paolo Paganelli; Elisabetta Storelli; Alberto Gatto; Marco FerrariQuantum InformationDigital signatures, Error analysis, Forgery, Hash functions, NIST, Protocols, Quantum channels, Quantum state, Qubit, Standards

This article introduces generalized quantum-assisted digital signature (GQaDS), an improved version of a recently proposed scheme whose information-theoretic security is inherited by adopting quantum key distribution keys for digital signature purposes. Its security against forging is computed considering a trial-and-error approach taken by the malicious forger, and GQaDS parameters are optimized via an analytical approach […]

Simulation of Shor Algorithm for Discrete Logarithm Problems With Comprehensive Pairs of Modulo p and Order q

July 21, 2025Kaito Kishi; Junpei Yamaguchi; Tetsuya Izu; Noboru KunihiroQuantum InformationComputers, Cryptography, Fourier transforms, Logic gates, Noise measurement, Quantum algorithm, Quantum circuit, Quantum computing, Qubit, Registers

Abstract: The discrete logarithm problem (DLP) over finite fields, commonly used in classical cryptography, has no known polynomial-time algorithm on classical computers. However, Shor has provided its polynomial-time algorithm on quantum computers. Nevertheless, there are only few examples simulating quantum circuits that operate on general pairs of modulo p and order q. In this article, […]

Fidelity-Aware Multipath Routing for Multipartite State Distribution in Quantum Networks

July 14, 2025Evan Sutcliffe; Alejandra BeghelliQuantum InternetNoise measurement, Performance evaluation, Probabilistic logic, Quantum entanglement, Quantum networks, Qubit, Routing, Routing protocols, Stars, Steiner trees

Abstract: We consider the problem of distributing entangled multipartite states across a quantum network with improved distribution rate and fidelity. For this, we propose fidelity-aware multipath routing protocols, assess their performance in terms of the rate and fidelity of the distributed Greenberger–Horne–Zeilinger (GHZ) states, and compare such performance against that of single-path routing. Simulation results […]

SU(4) Gate Design via Unitary Process Tomography: Its Application to Cross-Resonance-Based Superconducting Quantum Devices

July 3, 2025Michihiko Sugawara; Takahiko SatohPhysical ImplementationsCalibration, Coherence time, Logic gates, Qubit, Resonance, Schedules, Superconducting microwave devices, Systematics, Tensors, Tomography

Abstract: In this article, we present a novel approach for implementing pulse-efficient SU(4) gates on cross resonance (CR)-based superconducting quantum devices. Our method introduces a parameterized unitary derived from the CR-Hamiltonian propagator, which accounts for ZZ-interactions. Leveraging the Weyl chamber’s geometric structure, we successfully realize a continuous two-qubit basis gate, RZZ(θ), as an echo-free pulse […]

Control of a Josephson Digital Phase Detector via an SFQ-Based Flux Bias Driver

June 26, 2025Laura Di Marino; Luigi Di Palma; Michele Riccio; Francesco Fienga; Marco Arzeo; Oleg MukhanovQuantum ComputingDetectors, Integrated circuit modeling, Josephson junctions, Microwave theory and techniques, Noise, Oscillators, Phase detection, Qubit, Superconducting microwave devices, Switches

Abstract: Quantum computation requires high-fidelity qubit readout, preserving the quantum state. In the case of superconductings qubits, readout is typically performed using a complex analog experimental setup operating at room temperature, which poses significant technological and economic barriers to large system scalability. An alternative approach is to perform a cryogenic on-chip qubit readout based on […]

Cryo-CMOS Bias-Voltage Generation and Demultiplexing at mK Temperatures for Large-Scale Arrays of Quantum Devices

June 16, 2025Job van Staveren; Luc Enthoven; Peter Luka Bavdaz; Marcel Meyer; Corentin Déprez; Ville NuutinenQuantum ComputingCryogenics, Demultiplexing, Electrodes, Electromagnetic heating, FinFETs, Logic gates, Program processors, Qubit, Voltage control, Wiring

Abstract: The rapidly growing number of qubits in semiconductor quantum computers requires a scalable control interface, including the efficient generation of dc bias voltages for gate electrodes. To avoid unrealistically complex wiring between any room-temperature electronics and the cryogenic qubits, this article presents an integrated cryogenic solution for the bias-voltage generation and distribution for large-scale […]

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 […]