Spatiotemporally Correlated Error Bursts in Fluxonium Qubits

Spatiotemporally correlated error bursts, which arise from quasiparticles generated by ionizing radiation and mechanical noise, represent a challenge toward implementing quantum error correction on superconducting quantum processors. In this study, we investigate these error bursts in fluxonium qubits, a circuit architecture noted for its long coherence times and demonstrated high-fidelity control. Of particular interest is how the susceptibility to error bursts varies with applied external flux, which can reveal the respective contributions of quasiparticle tunneling through the small Josephson junction versus the superinductor array of the circuit. We present experimental progress towards these goals, which serve to advance ongoing efforts to enhance the performance of superconducting qubits and provide guidance for mitigating spatiotemporally correlated errors in fluxonium devices.