A superconducting quantum simulator based on a photonic-bandgap metamaterial
Experimental realizations of engineerable quantum systems provide insights into exotic quantum many-body concepts that are intractable with available classical methods. A key challenge in the development of modern quantum simulators is to maintain the level of connectivity and control during scale-up. While majority of scalable quantum simulation and computation architectures to date feature nearest-neighbor interactions limited by their local nature of coupling, long-range interacting quantum systems—exhibiting fast build-up of quantum correlation and entanglement—provide new approaches for studying quantum many-body phenomena and investigating quantum error-correction schemes in the near term. Utilization of extensible quantum bus such as a photonic waveguide provides a natural direction to investigate such many-body quantum systems where qubits interact non-locally by exchange of photons along the bus. Following this idea, here we demonstrate a 10-qubit superconducting quantum simulator with tunable long-range connectivity and individual addressing, constructed from a scalable metamaterial-based waveguide with photonic bandgaps. We study many-body quench dynamics showing a crossover between integrability and ergodicity, enabled by the various hopping range realized in our system. The widely tunable range of parameters demonstrated in our work enables study of different regimes of quantum chaos and thermalization, and more broadly, provides a novel class of accessible Hamiltonians for analog quantum simulation in superconducting circuits.