Towards Error Budgeting for Superconducting Modular Quantum Architecture Designs

This paper addresses frequency crowding constraints in modular quantum architecture design, focusing on the SNAIL-based quantum modules. Two key objectives are explored. First, we present physics-informed design constraints by describing a physical model for realizable gates within a SNAIL module and building a fidelity model using error budgeting derived from device characteristics. Second, we tackle the allocation problem by analyzing the impact of frequency crowding on gate fidelity as the radix of the module increases. We explore whether the gate fidelity can be preserved with a discrete set of qubit frequencies while adhering to defined separation thresholds. This work offers insights into novel quantum architectures and coupled optimization techniques to mitigate the effects of unstable noise and improve overall gate performance.