Multi-FPGA Synchronization and Data Communication for Quantum Control and Measurement

TL;DR

This paper presents a scalable multi-FPGA synchronization and data communication framework for quantum control systems, enabling real-time feedback and multi-qubit operations in larger quantum computers.

Contribution

It introduces a novel clock synchronization and fiber-based data transfer system integrated into an open-source quantum control platform for multi-board quantum computing.

Findings

Effective clock synchronization across multiple RFSoC boards.

Low-latency data transfer over fiber links.

Successful demonstration with a qubit readout emulator.

Abstract

In the last decade, quantum computing has grown from novel physics experiments with a few qubits to commercial systems with hundreds of qubits. As quantum computers continue to grow in qubit count, the classical control systems must scale correspondingly. While a few expensive multi-board commercial solutions exist, most open-source solutions are limited to single-board radio frequency system-on-chip (RFSoC). The essential requirements for a multi-board solution are clock synchronization among multiple boards and the ability to transfer data with low latency for performing real-time feedback. In this work, we design a clock synchronization framework to distribute deterministic clock and synchronize the clock counters across multiple RFSoC boards to generate time-aligned radio frequency (RF) pulses used to control qubits. We also develop a data communication system over a fiber link to transfer quantum measurement data among multiple field-programmable gate arrays (FPGAs). This clock synchronization and data communication module has been integrated into the open-source quantum control system, QubiC, to enable the execution of quantum algorithms across multiple boards. We demonstrate the effectiveness of our design through bench tests with a room-temperature qubit readout emulator.