Quantum Computing is a rapidly growing field, where room-temperature control electronics have become a major bottleneck for scalability, particularly in academic environments, where open control stacks and cost-effectiveness are essential. In this paper, we present initial results of our approach to scaling multiple instances of the Quantum Interface Controller (QiController), a control and readout electronic stack developed at the Karlsruhe Institute of Technology. We outline key concepts such as low-latency communication and clock synchronization required for a scalable architecture leveraging an ATCA-based platform, validate these concepts through several demonstrator setups, and present promising preliminary results. We also discuss the remaining challenges in developing a fully scalable system.
Quantum Computing is a rapidly growing field, where room-temperature control electronics have become a major bottleneck for scalability, particularly in academic environments, where open control stacks and cost-effectiveness are essential. In this paper, we present initial results of our approach to scaling multiple instances of the Quantum Interface Controller (QiController), a control and readout electronic stack developed at the Karlsruhe Institute of Technology. We outline key concepts such as low-latency communication and clock synchronization required for a scalable architecture leveraging an ATCA-based platform, validate these concepts through several demonstrator setups, and present promising preliminary results. We also discuss the remaining challenges in developing a fully scalable system.
Quantum computing has the potential to revolutionize computation by solving complex problems in a way that classical computers cannot. However, robust and scalable qubit manipulation and control electronics are needed to exploit this potential. Academic efforts in this area are sparse, especially in terms of scalability to hundreds or thousands of qubits. The mod-ular and scalable Quantum Interface Controller (QiController), a room-temperature qubit control architecture, addresses this gap. It is implemented using the Advanced Telecommunications Computing Architecture (ATCA) and its dual-dual star topology. The system has two boards: a “Hub” with an AMD Xilinx RFSoC and a “Node” with peripheral FPGAs and DACs for low-latency flux control. This paper describes the system architecture and firmware developments for multi-board synchronization.
Quantum bit control systems using room temperature electronics provide universities and research institutions a cost-effective entry into quantum computing. Various approaches address the need for straightforward qubit controllers, particularly those based on AMD's next-generation RFSoC FPGA, which integrate adaptive SoCs with internal ADCs and DACs. As superconducting qubit architectures advance to incorporate flux elements for direct Z axis control and the number of qubits grows, the demand for high-quality and numerous control channels increases. This paper explores the requirements for integrating and expanding the QiController electronics from Karlsruhe Institute of Technology. The new system includes up to ten cards capable of driving a total of 240 direct flux lines. Our joint system design leverages the modularity, scalability, and thermal management of the industrial Standard ATCA, ensuring robust performance and ease of maintenance in this multi-FPGA setup. Initial unit tests of the electronics show improvements in noise levels and quality, suggesting that future verification on real qubit devices could establish this approach as a viable solution for scalable room-temperature control hardware.
Quantum computing requires scalable control hard-ware capable of generating precise signals and synchronizing operations across large numbers of qubits. However, existing control systems are typically optimized for specific qubit modalities, leading to limited interoperability, high development cost, and poor scalability as device architectures evolve. To address this challenge, a heterogeneous and modular control architecture supporting multiple qubit platforms was previously proposed.This paper evaluates FPGA resource requirements and implementation characteristics of the architecture across four controller variants targeting high-frequency microwave, mid-frequency RF, low-frequency DAC, and digital GPIO applications. The results show that core architectural components—including networking, synchronization, and waveform generation—maintain nearly constant hardware usage across platforms, while resource scaling primarily depends on data throughput requirements rather than architectural complexity.Moreover, the architecture is demonstrated on both high-end FPGAs with high-bandwidth memory and cost-efficient embedded devices, confirming portability and deployment flexibility. These findings validate the feasibility of a unified control framework suitable for heterogeneous quantum systems and large-scale control networks.
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.
A scalable control architecture for superconducting quantum processors is essential as the number of qubits increases and coherent multi-qubit operations span beyond the capacity of a single control module. The Quantum Instrumentation Control Kit (QICK), built on AMD RFSoC platforms, offers a flexible open-source framework for pulse-level qubit control but lacks native support for multi-board synchronization, limiting its applicability to mid- and large-scale quantum devices. To overcome this limitation, we introduce Manarat, a scalable multi-board control platform based on QICK that incorporates hardware, firmware, and software enhancements to enable sub-100 ps timing alignment across multiple AMD ZCU216 RFSoC boards. Our system integrates a low-jitter clock distribution network, modifications to the tProcessor, and a synchronization scheme to ensure deterministic alignment of program execution across boards. It also includes a custom analog front-end for flux control that combines high-speed RF signals with software-programmable DC biasing voltages generated by a low-noise, high-precision DAC. These capabilities are complemented by a software stack capable of orchestrating synchronized multi-board experiments and fully integrated with the open-source Qibo framework for quantum device calibration and algorithm execution. We validate Manarat on a 10-qubit superconducting processor controlled by two RFSoC boards, demonstrating reliable execution of synchronized control sequences for cross-board CZ gate calibration. These results confirm that sub-nanosecond synchronization and coherent control are achievable across multiple RFSoC boards, enabling scalable operation of superconducting quantum computers.
This paper proposes a control system capable of supporting various qubit platforms by combining control units with different specifications with a lightweight and common interface. To realize quantum computers, several qubit platforms, such as superconducting qubits, neutral atoms, ion traps, and semi-conductor quantum dots, are being researched. Each platform requires different microwave frequencies, channel numbers, intensities, and time scales for control. However, building individual control systems for each platform is not practical from a development cost perspective. Therefore, the standardization of control systems is desired. In practice, common languages and libraries for pulse control software are being developed as both commercial products and open-source projects. However, no widely adopted standardization methods currently exist for the control layer of electrical signals responsible for qubit manipulation. This paper first organizes the challenges in standardizing the control layer of electrical signals. It then proposes an architecture to address these challenges, featuring Ethernet-based unit inter-connections, a synchronization system based on time and pulses, and a lightweight and flexible waveform generation method. The proposed approach allows for practical cost adaptation to various types of qubits by connecting electronic circuits with specifications required for the target qubit platform.