A scalable superconducting quantum architecture with long-range connectivity
An architecture with high connectivity lays the groundwork for studying crucial topics in quantum information science. Among them are quantum simulations of long-range interacting phases of matter that are challenging to model classically and quantum computation involving non-local gates. However, most scalable quantum platforms feature nearest-neighbor interaction because of their local nature of coupling. In this talk, I will discuss our approach to going beyond this limit by utilizing the photon-mediated interaction, which enables us to build a scalable quantum simulator architecture based on superconducting qubits [1]. In this case, the long-range qubit-qubit interaction is mediated via an extensible quantum bus constructed from a microwave photonic bandgap metamaterial, empowering high-fidelity qubit readout while protecting the qubits from radiative decoherence [2]. As an initial demonstration, we realize a 10-qubit simulator of the one-dimensional Bose-Hubbard model with in-situ tunability of both the hopping range and the on-site interaction. By performing many-body quench experiments, we characterize the Hamiltonian using a quantum-chaos-based protocol and observe the effect of tunable long-range hopping, showing a crossover from integrable to ergodic many-body evolution. Looking forward, the metamaterial quantum bus can be extended to a two-dimensional lattice and used to generate other tailored lattice connectivity [3], greatly expanding the accessible Hamiltonians for analog quantum simulation and the flexibility in implementing gate-based quantum computations using superconducting circuits.
[1] Zhang, X.*, Kim, E. J.*, Mark, D., Choi, S., & Painter, O. (2022). A scalable superconducting quantum simulator with long-range connectivity based on a photonic bandgap metamaterial. arXiv 2206.12803.
[2] Mirhosseini, M.*, Kim, E.*, Zhang, X., Sipahigil, A., Dieterle, P. B., Keller, A. J., ... & Painter, O. (2019). Cavity quantum electrodynamics with atom-like mirrors. Nature, 569(7758), 692-697.
[3] Kim, E*., Zhang, X.*, Ferreira, V. S., Banker, J., Iverson, J. K., Sipahigil, A., ... & Painter, O. (2021). Quantum electrodynamics in a topological waveguide. Physical Review X, 11(1), 011015.