Toward Scalable Heterogeneous Controller System for Various Quantum Computer by Using Multiple FPGAs

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.