Demonstration of fluxonium qubits based on highly-disordered spinodal materials

The reduced sensitivity to charge and flux noise of fluxonium qubits is mainly achieved by the inclusion of a high-impedance circuit element (i.e., large inductance and small capacitance). Such a circuit element, namely superinductor, is typically realized using either Josephson-junction arrays or disordered superconductor nanowires. Here we demonstrate that the highly-disordered spinodal superconducting material (Adv. Mater. 34, 202201268, 2022) is an alternative candidate for low-loss fluxonium qubits with improved process simplicity and robustness. In addition, the large tunability of such materials, e.g., chemical composition, meso/microscopic structures, and etc., provides new opportunities for the engineering and understanding of the decoherence of fluxonium qubits.