The transition of quantum technologies from laboratory-scale demonstrations to fault-tolerant and deployable systems is increasingly limited by the classical–quantum hardware interface. Although microwave subsystems for several leading quantum-computing platforms have been reviewed previously, the RF-to-terahertz hardware requirements that enable cross-platform maturation remain less systematically addressed. This article critically reviews RF-to-terahertz hardware for quantum technologies, focusing on cryogenic integration, high-density interconnects, and fabrication bottlenecks. Recent experimental efforts from the electronics engineering community are analyzed to identify shared limitations in low-temperature device modeling, thermal management, signal integrity, low-noise amplification, passive microwave structures, control and readout electronics, microwave-to-optical transduction, and scalable packaging. Competing approaches are assessed against common engineering criteria including RF and noise performance, bandwidth, power dissipation and thermal load, integration density, calibration complexity, fabrication reproducibility, and maturity toward scalable deployment. The review argues that future progress is no longer governed only by the optimization of individual components, but by the co-design of materials, devices, interconnects, control architectures, measurement chains, and manufacturing processes. In this framework, scalability, miniaturization, integration density, and reproducibility become central metrics for quantum hardware development. By synthesizing developments across quantum computing, sensing, communication, and networking platforms, this review provides a component-level roadmap for RF, microwave, terahertz, and electronics engineers working toward scalable, manufacturable, and interoperable quantum technology systems.
The transition of quantum technologies from laboratory-scale demonstrations to fault-tolerant and deployable systems is increasingly limited by the classical–quantum hardware interface. Although microwave subsystems for several leading quantum-computing platforms have been reviewed previously, the RF-to-terahertz hardware requirements that enable cross-platform maturation remain less systematically addressed. This article critically reviews RF-to-terahertz hardware for quantum technologies, focusing on cryogenic integration, high-density interconnects, and fabrication bottlenecks. Recent experimental efforts from the electronics engineering community are analyzed to identify shared limitations in low-temperature device modeling, thermal management, signal integrity, low-noise amplification, passive microwave structures, control and readout electronics, microwave-to-optical transduction, and scalable packaging. Competing approaches are assessed against common engineering criteria including RF and noise performance, bandwidth, power dissipation and thermal load, integration density, calibration complexity, fabrication reproducibility, and maturity toward scalable deployment. The review argues that future progress is no longer governed only by the optimization of individual components, but by the co-design of materials, devices, interconnects, control architectures, measurement chains, and manufacturing processes. In this framework, scalability, miniaturization, integration density, and reproducibility become central metrics for quantum hardware development. By synthesizing developments across quantum computing, sensing, communication, and networking platforms, this review provides a component-level roadmap for RF, microwave, terahertz, and electronics engineers working toward scalable, manufacturable, and interoperable quantum technology systems.
Superconducting qubits are pivotal in advancing quantum computing, poised for scale but limited by the complexity and fidelity of their control and readout systems, relying on RF and signal processing infrastructure. This survey serves as a comprehensive and technically grounded review of control and readout architectures tailored for superconducting qubits. Synthesizing insights from device physics, circuit design, microwave engineering, signal processing, and cryogenic integration, this work details the practicalities of RF pulse generation, signal synthesis, and readout signal analysis for quantum systems. it covers key requirements, parameters, and pulse engineering techniques, including commonly used envelopes like Gaussian and DRAG designs. Moving to the system level, this survey systematically classifies and critically analyses current architectural strategies (covering key areas like frequency conversion, waveform management, and system infrastructure) and technology platforms (including adaptive classical control stacks, cryogenic CMOS circuits, and novel interconnects and interfaces), evaluating their trade-offs in performance. Extensive literature analysis identifies prevailing limitations such as wiring complexity, thermal budget constraints, latency, and power consumption, while highlighting underexplored opportunities for on-chip signal processing and novel interconnects, drawing analogies to advanced communication systems design. By consolidating diverse control paradigms and critically evaluating their trade-offs, this survey provides a unified foundation for designing next-generation quantum control stacks. Finally, a forward-looking roadmap outlines key trends in monolithic integration, cryo-compatible digital architectures, and physics-informed hardware co-design, offering both a retrospective synthesis and a prospective vision for quantum hardware engineering beyond the NISQ era.
Quantum computing has made significant strides, with hardware platforms now advanced enough to tackle the challenges of scaling up to larger and more robust systems. Central to this progression is the interface between quantum processors, comprising isolated qubits, and the classical systems required for their control and readout. As these systems transition from few-qubit devices to fault-tolerant architectures, the complexity of this quantum-classical interaction poses significant engineering challenges. Field-Programmable Gate Arrays (FPGAs) have emerged as an adaptable and efficient solution, offering realtime control, low-latency operations, and seamless integration. This review delves into current FPGA-based platforms, including commercial systems, as well as open-source solutions developed by academic research groups. The architecture, features, and contributions of these platforms to addressing scalability and integration issues are thoroughly examined. Additionally, the review highlights innovations in cryogeniccompatible controllers and explores the potential of Cryo-FPGAs to reduce noise and improve fidelity in quantum systems. By providing a comprehensive analysis of current technologies and identifying opportunities for advancement, this review offers valuable insights for researchers and engineers working to develop scalable quantum computing solutions.
Abstract Development of large-scale quantum computing systems will require radio frequency (RF) and microwave technologies operating reliably at cryogenic temperatures down to tens of milli-Kelvin (mK). The quantum bits in the most promising quantum computing technologies such as the superconducting quantum computing are designed using principles of microwave engineering and operated using microwave signals. The control, readout, and coupling of qubits are implemented using a network of microwave components operating at various temperature stages. To ensure reliable operation of quantum computing systems, it is critical to ensure optimal performance of these microwave components and qubits at their respective operating temperatures, which can be as low as mK temperatures. It is, therefore, critical to understand the microwave characteristics of waveforms, components, circuits, networks, and systems at cryogenic temperatures. The UK’s National Physical Laboratory (NPL) is focussed on developing new microwave measurement capabilities through the UK’s National Quantum Technologies Programme to address various microwave test and measurement challenges in quantum computing. This includes the development of various measurement capabilities to characterize the microwave performance of quantum and microwave devices and substrate materials at cryogenic temperatures. This paper summarizes the roadmap of activities at NPL to address these microwave metrology challenges in quantum computing.
The terahertz (THz) regime of electromagnetic radiation, spanning frequencies from 0.1 to tens of THz, has found widespread use in communication, sensing, quality control, and biomedical applications. Quantum realm of THz domain is, however, still at an earlier development stage and mostly referenced in the context of applied technologies for single-photon generation and detection, with rarer examples of exploration of quantum phenomena. Recent advances in cryogenic hybrid quantum systems suggest that THz radiation may play a pivotal role in emerging quantum technologies. These systems, which require operation at milliKelvin temperatures, offer new opportunities for quantum memory, frequency transduction, and precision measurements, with THz radiation enabling access to molecular vibrational, rotational, and librational transitions. Despite progress in THz components at low temperatures, there remains a critical gap in the systematic integration of THz technologies within sub-Kelvin cryogenic platforms such as dilution refrigerators and adiabatic demagnetization systems. This review presents a comprehensive roadmap for the development of THz photonics in extreme cryogenic environments, addressing implementation strategies, material considerations, waveguide and fiber technologies, and quantum-compatible detection schemes. We further highlight prospective applications in quantum optics, superconductivity, and fundamental physics, aiming to establish THz photonics as a versatile tool for controlling and probing quantum states in sub-Kelvin regimes.
The terahertz (THz) regime of electromagnetic radiation, spanning frequencies from 0.1 to tens of THz, has found widespread use in communication, sensing, quality control, and biomedical applications. Quantum realm of THz domain is, however, still at an earlier development stage and mostly referenced in the context of applied technologies for single-photon generation and detection, with rarer examples of exploration of quantum phenomena. Recent advances in cryogenic hybrid quantum systems suggest that THz radiation may play a pivotal role in emerging quantum technologies. These systems, which require operation at milliKelvin temperatures, offer new opportunities for quantum memory, frequency transduction, and precision measurements, with THz radiation enabling access to molecular vibrational, rotational, and librational transitions. Despite progress in THz components at low temperatures, there remains a critical gap in the systematic integration of THz technologies within sub-Kelvin cryogenic platforms such as dilution refrigerators and adiabatic demagnetization systems. This review presents a comprehensive roadmap for the development of THz photonics in extreme cryogenic environments, addressing implementation strategies, material considerations, waveguide and fiber technologies, and quantum-compatible detection schemes. We further highlight prospective applications in quantum optics, superconductivity, and fundamental physics, aiming to establish THz photonics as a versatile tool for controlling and probing quantum states in sub-Kelvin regimes.
Quantum computing is transitioning from theoretical development to scalable hardware implementation, yet qubit instability caused by thermal noise, decoherence, electromagnetic interference, and material imperfections remains a central barrier to achieving fault-tolerant quantum processing. Cryogenic materials and ultra-low noise environments have emerged as foundational requirements in stabilizing qubit operation, prolonging coherence time, and enabling quantum error correction for large-scale computational reliability. This paper investigates critical advancements in cryogenic superconductors, magnetic-shielding architectures, dilution refrigeration systems, noise-suppressed signal routing, phonon-limited material engineering, and quantum-grade chip fabrication. Through experimental and simulated benchmarking, we analyze coherence improvements, qubit lifetimes, fabrication tolerances, and environmental noise thresholds necessary for fault-tolerant operation. Data findings confirm that next-generation cryogenic material stacks reduce qubit error rates by 83%, increase coherence time >500 μs in transmon qubits, and support quantum error correction thresholds for practical scalability. The study provides a roadmap for manufacturing stable quantum hardware through material purity innovations, thermal isolation architectures, and cryogenic noise-management frameworks.