Weakly Flux-Tunable Superconducting Qubit

Flux-tunable qubits are a useful resource for superconducting quantum processors. They can be used to perform cPhase gates, facilitate fast reset protocols, avoid qubit-frequency collisions in large processors, and enable certain readout schemes. However, flux-tunable suffer from trade-off between their tunability range sensitivity flux noise. Optimizing this is particularly important enabling fast, high-fidelity, all-microwave cross-resonance gates large, high-coherence This mainly because set stringent conditions on the frequency landscape of neighboring qubits, which difficult satisfy with non-tunable transmons due relatively fabrication imprecision. To solve problem, we realize coherent, flux-tunable, transmon-like qubit, exhibits as small 43 MHz, whose frequency, anharmonicity by few experimentally achievable design parameters. Such weakly tunable qubit avoiding lattice while limiting its susceptibility