The classical-quantum system heterogeneity (different data characteristics, execution paradigms and synchronization mechanism etc.) renders existing distributed communication mechanisms (e.g. MPI, NCCL etc.) inadequate. This bottleneck severely impairs operational synergy and programming efficiency. Thus, the performance of hybrid applications on classical-quantum heterogeneous infrastructures is directly limited. To address these challenges, this paper proposes a message-passing library tailored for large-scale classical-quantum heterogeneous distributed computing, referred to as MPI-Q. The design centers on three mechanisms. First, it defines a heterogeneous hybrid communication domain that achieves unified management of classical and quantum processes in heterogeneous hybrid systems. Second, it uses a lightweight communication path that allows classical control nodes to send device-ready waveform data directly to quantum MonitorProcesses, avoiding unnecessary relay stages. Third, it establishes a heterogeneous hybrid synchronization mechanism to tackle the problem of timing control for multi-node quantum operations. While retaining the traditional MPI programming model, MPI-Q achieves extension toward quantum subsystems. Experiments on distributed GHZ state preparation demonstrate that this model exhibits near-linear scalability, achieving a maximum speedup of 18.76 times on 24 quantum nodes. This proves that the library can effectively support large-scale heterogeneous hybrid distributed computing applications, filling the technical gap in this field.

翻译：经典-量子系统异构性（不同数据特征、执行范式及同步机制等）导致现有分布式通信机制（如MPI、NCCL等）难以适用。该瓶颈严重损害了操作协同性与编程效率，进而直接限制了混合应用在经典-量子异构基础设施上的性能表现。为应对上述挑战，本文提出一种面向大规模经典-量子异构分布式计算的消息传递库（称为MPI-Q）。其设计围绕三项核心机制：首先，定义异构混合通信域，实现异构混合系统中经典与量子进程的统一管理；其次，采用轻量化通信路径，使经典控制节点可直接将设备就绪的波形数据发送至量子监控进程，避免不必要的中间中继环节；第三，建立异构混合同步机制，以解决多节点量子操作的时序控制问题。该库在保留传统MPI编程模型的同时，实现了向量子子系统的扩展。基于分布式GHZ态制备的实验表明，该模型具有近线性可扩展性，在24个量子节点上实现了最高18.76倍的加速比，证明了该库能有效支撑大规模异构混合分布式计算应用，填补了该领域的技术空白。