QIsim: Architecting 10+K Qubit QC Interfaces Toward Quantum Supremacy

A 10+K qubit Quantum-Classical Interface (QCI) is essential to realize the quantum supremacy. However, it is extremely challenging to architect scalable QCIs due to the complex scalability trade-offs regarding operating temperatures, device and wire technologies, and microarchitecture designs. Therefore, architects need a modeling tool to evaluate various QCI design choices and lead to an optimal scalable QCI architecture. In this paper, we propose (1) QIsim, an open-source QCI simulation framework, and (2) novel architectural optimizations for designing 10+K qubit QCIs toward quantum supremacy. To achieve the goal, we first implement detailed QCI microarchitectures to model all the existing temperature and technology candidates. Next, based on the microarchitectures, we develop our scalability-analysis tool (QIsim) and thoroughly validate it using previous works, post-layout analyses, and real quantum-machine experiments. Finally, we successfully develop our 60,000+ qubit-scale QCI designs by applying eight architectural optimizations driven by QIsim.