Characterization of a superconducting metamaterial quantum many-body simulator

Superconducting quantum circuits are an emerging hardware platform for directly simulating quantum many-body systems with precise control and read-out at the single qubit (spin) level. Microwave metamaterial circuits introduced into the wiring of a superconducting quantum processor can serve both as a quantum bus for mediating tunable, long-range coupling among qubits, and as a read-out bus for multiplexed qubit read-out. In this talk, we describe our work to realize and characterize a metamaterial-based quantum processor with 10 qubits. We characterize both single-qubit properties including coherence and anharmonicity, and the long-range coupling among qubits. Using the metamaterial as a Purcell filter, we demonstrate multiplexed high-fidelity single-shot readout for all 10 qubits. The many-body Hamiltonian is probed as a function of qubit detuning from the two photonic bandedges of the metamaterial, revealing subtle differences in the accessible quantum phases of the Bose-Hubbard model. Based on the measured system properties, we also propose several new opportunities for many-body simulation on such a processor.