Performance analysis of interconnection networks for distributed quantum computing

Abstract

Quantum computing has the potential to solve complicated problems that are impossible for classical servers. Nevertheless, the applications of current quantum processors are restricted by their limited qubit capacity. Distributed Quantum Computing (DQC) is promising to scale up the computing capability by interconnecting quantum processors and performing computing collectively. The network interconnecting quantum processors can impact the efficiency of DQC. In this paper, we analyze and compare the performance of various interconnection networks for DQC. First, we meticulously derive the success probabilities of entanglement generation and the fidelity of shared Bell states generated within three typical static networks: line, ring, and grid. In addition, we propose a switching network with a minimal number of switch stages and evaluate its performance in terms of probability and fidelity. Moreover, we conduct extensive simulations based on real-world parameters to compare the static and switching networks, and the results reveal that the switching network performs better and is more scalable.