Accurate modeling of the storage and buffer nonlinearities in an integrated cat qubit system

Cat qubits constitute a promising path towards hardware-efficient error correction based on biased noise. In this talk we focus on dissipatively stabilized cat qubits implemented in superconducting circuits. A primary challenge with dissipative stabilization of cat qubits is to realize strong nonlinear mixing between a storage mode and a buffer mode to realize the target dissipation channel, without introducing undesired nonlinearities on these modes. We present theoretical models of a cat qubit system that accurately captures the storage and buffer nonlinearities in an integrated setting with many coupled modes.