QuCloudSim: A Customizable Discrete Event Simulator for Quantum Cloud Computing Enviroment

Current quantum computing service providers operate in a cloud-based model, hosting expensive quantum computers in data centers for remote access. However, in the Noisy Intermediate-Scale Quantum (NISQ) era, quantum hardware is limited in terms of qubit count and connectivity. To address scalability challenges, future quantum cloud infrastructures will likely adopt a modular architecture where Quantum Processing Units (QPUs) are interconnected via quantum networks using various hardware technologies. In such systems, challenges like resource management, scheduling, and placement become critical, yet there is currently a gap in simulation tools capable of modeling quantum computers connected via quantum networks. To address this, we propose QuCloudSim, a quantum cloud simulator that adopts a modular design to model various hardware components within a quantum cloud environment. It employs discrete event simulation to replicate real-world scenarios with concurrent user requests, and our evaluation of different scheduling and placement methods demonstrates that QuCloudSim effectively models modular quantum cloud systems while providing valuable insights for developing scalable quantum cloud infrastructures.