Loss Mechanisms in Fluxonium Qubits

Innovative circuit design and material engineering has led the rapid growth of coherence times in superconducting qubits. The fluxonium circuit is emerging as a promising qubit, owing to its large anharmonicity and low frequency transitions at flux sweet spots. Although significant progress has been made in elucidating the origins of loss in fluxonium qubits, there is still work to do to comprehensively understand the physical mechanisms that limit coherence. Here, we present preliminary work exploring both materials and circuit design, to help elucidate the origins of loss in fluxonium circuits. We place this in the context of other reports of theory and experiments exploring loss mechanisms in fluxonium circuits.