HI-HCQC: A Tightly-Coupled Hardware Interface with High-Efficiency Communication for Hybrid Classical-Quantum Computing

2026-06-16

AI Summary

This work addresses the high latency and low throughput inherent in loosely coupled classical–quantum computing interfaces, such as Ethernet. To overcome these limitations, the authors propose HI-HCQC—a tightly coupled hardware interface based on RFSoC technology that integrates PCIe Gen3 x8 architecture with embedded RF-DAC/ADCs, programmable logic, ARM processors, and clock synchronization circuitry. The design supports six control channels and one multiplexed readout channel, enabling direct microwave pulse synthesis, real-time qubit readout, and high-speed data transfer. By tightly integrating classical control electronics with quantum hardware, HI-HCQC significantly reduces end-to-end latency and enhances task throughput, thereby establishing a practical and scalable hardware foundation for efficient hybrid quantum systems.

Abstract

Hybrid classical-quantum computing requires frequent data exchange between classical processors and quantum control hardware. However, existing superconducting quantum control systems are commonly connected through loosely coupled interfaces such as Ethernet, resulting in high communication latency and limited task throughput. To address this issue, we present HI-HCQC, an RFSoC-based hardware interface for tightly coupled hybrid classical-quantum computing. HI-HCQC integrates high-speed RF-DACs, RF-ADCs, programmable logic, embedded processors, clock synchronization circuits, and a PCIe Gen3 x8 interface, enabling direct microwave pulse synthesis, qubit readout, and high-throughput data transfer between host servers and quantum measurement-control units. Experimental results show that HI-HCQC supports six control channels and one multiplexed readout channel, achieves stable microwave generation and acquisition, and successfully performs qubit spectroscopy, Rabi oscillation, T1 measurement, single-shot readout, randomized benchmarking, and CZ-gate characterization. Compared with a conventional control system, HI-HCQC reduces end-to-end execution latency for representative quantum gate and circuit tasks and significantly improves task throughput. These results demonstrate that PCIe-coupled RFSoC control hardware provides a practical foundation for scalable and efficient hybrid classical-quantum computing systems.

Problem

• hybrid classical-quantum computing
• communication latency
• task throughput
• tightly-coupled interface
• quantum control systems

Innovation

• RFSoC
• tight coupling
• PCIe interface
• quantum control hardware
• low-latency communication