Q2Logic: An Coarse-Grained Architecture targeting Schrödinger Quantum Circuit Simulations

Abstract: Quantum computing is emerging as an important (but radical) technology that might take us beyond Moore's law for certain applications. Today, in parallel with improving quantum computers, computer scientists are relying heavily on quantum circuit simulators to develop algorithms. Most existing quantum circuit simulators run on general-purpose CPUs or GPUs. However, at the same time, quantum circuits themselves offer multiple opportunities for parallelization, some of which could map better to other architecture -- architectures such as reconfigurable systems. In this early work, we created a quantum circuit simulator system called Q2Logic. Q2Logic is a coarse-grained reconfigurable architecture (CGRA) implemented as an overlay on Field-Programmable Gate Arrays (FPGAs), but specialized towards quantum simulations. We described how Q2Logic has been created and reveal implementation details, limitations, and opportunities. We end the study by empirically comparing the performance of Q2Logic (running on a Intel Agilex FPGA) against the state-of-the-art framework SVSim (running on a modern processor), showing improvements in three large circuits (#qbit=27), where Q2Logic can be up-to ~7x faster.