Experimental control-Z two qubit gate on 2D Kerr cats

We investigate the realization of scalable, high-quality multi-qubit systems compatible with quantum error correction for noise-biased qubits. Previous research has focused on implementing Kerr-cat qubits using superconducting circuits, where Schrödinger cat states have exhibited long lifetimes and high coherence even at large cat sizes. However, a systematic study of two-qubit gates between Kerr-cat qubits—particularly to assess whether they can achieve fidelities below the fault-tolerant threshold—has remained incomplete. Here, we design and characterize the interaction between two coupled Kerr-cat qubits based on our high-coherence planar architecture with on-chip Purcell filters. We implement and analyze gate performance through randomized benchmarking and gate set tomography, demonstrating the feasibility of high-fidelity operations in this noise-biased bosonic platform.