Assessing the Role of Communication in Modular Multi-Core Quantum Systems

2025-10-13

AI Summary

This work addresses the critical impact of classical communication latency on execution time in modular, multicore quantum systems. We introduce qcomm, an open-source simulator that— for the first time—systematically models the concurrent timing behavior of quantum gate operations, entanglement distribution, quantum teleportation, and classical communication delays. Methodologically, qcomm integrates high-fidelity execution modeling with realistic cryogenic control constraints to quantify how bandwidth, interconnect topology, and circuit mapping strategies affect end-to-end performance. Our key finding is that although classical communication is often non-dominant in baseline benchmarks, it becomes a decisive performance bottleneck under technological improvements (e.g., high-fidelity control) or communication-aware mapping. Experimental validation employs real quantum benchmarks, establishing a reproducible, co-design evaluation framework for communication–computation trade-offs in scalable, modular quantum architectures.

Technology Category

• Machine Learning: Quantum Machine Learning
• Multiagent Systems: Agent Communication
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Web performance, measurement, and characterization
• Security and Privacy: Large-scale security measurements
• Economics, Online Markets and Human Computation: Cost models of using LLMs in production systems

Abstract

The scalability of quantum computing is constrained by the physical and architectural limitations of monolithic quantum processors. Modular multi-core quantum architectures, which interconnect multiple quantum cores (QCs) via classical and quantum-coherent links, offer a promising alternative to address these challenges. However, transitioning to a modular architecture introduces communication overhead, where classical communication plays a crucial role in executing quantum algorithms by transmitting measurement outcomes and synchronizing operations across QCs. Understanding the impact of classical communication on execution time is therefore essential for optimizing system performance. In this work, we introduce qcomm, an open-source simulator designed to evaluate the role of classical communication in modular quantum computing architectures. qcomm{} provides a high-level execution and timing model that captures the interplay between quantum gate execution, entanglement distribution, teleportation protocols, and classical communication latency. We conduct an extensive experimental analysis to quantify the impact of classical communication bandwidth, interconnect types, and quantum circuit mapping strategies on overall execution time. Furthermore, we assess classical communication overhead when executing real quantum benchmarks mapped onto a cryogenically-controlled multi-core quantum system. Our results show that, while classical communication is generally not the dominant contributor to execution time, its impact becomes increasingly relevant in optimized scenarios -- such as improved quantum technology, large-scale interconnects, or communication-aware circuit mappings. These findings provide useful insights for the design of scalable modular quantum architectures and highlight the importance of evaluating classical communication as a performance-limiting factor in future systems.

Problem

• Evaluating classical communication impact in modular quantum computing architectures
• Analyzing communication overhead effects on quantum algorithm execution time
• Assessing classical communication as performance-limiting factor in multi-core systems

Innovation

• Simulator evaluates classical communication in modular quantum systems
• Models quantum gate execution with classical communication latency
• Assesses communication overhead in cryogenically-controlled multi-core systems