  Superconducting circuits have emerged as a promising platform to build
quantum processors. The challenge of designing a circuit is to compromise
between realizing a set of performance metrics and reducing circuit complexity
and noise sensitivity. At the same time, one needs to explore a large design
space, and computational approaches often yield long simulation times. Here we
automate the circuit design task using SCILLA, a software for automated
discovery of superconducting circuits. SCILLA performs a parallelized,
closed-loop optimization to design circuit diagrams that match pre-defined
properties such as spectral features and noise sensitivities. We employ it to
discover 4-local couplers for superconducting flux qubits and identify a
circuit that outperforms an existing proposal with similar circuit structure in
terms of coupling strength and noise resilience for experimentally accessible
parameters. This work demonstrates how automated discovery can facilitate the
design of complex circuit architectures for quantum information processing.
