IQIM Postdoctoral and Graduate Student Seminar

Friday, September 9, 2022
12:00pm to 1:00pm
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East Bridge 114
A scalable superconducting quantum architecture with long-range connectivity
Xueyue (Sherry) Zhang, Graduate Student, Painter Group,

Abstract: 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. 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, 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.

Lunch will be provided, following the talk, on the lawn outside the Bridge arcade.

Attendees joining in person must demonstrate that they comply with Caltech's vaccination requirements (Caltech ID or AWS ID required).

Amid the recent increase in COVID-19 cases on campus due to the arrival of the highly infectious BA.2 subvariant in Los Angeles County and a return to routine social activities, the Institute has reinstated its requirement that high-quality masks (surgical, N95s, KN95s, or KF95s) must be worn in all indoor locations on campus.

For more information, please contact Marcia Brown by phone at 626-395-4013 or by email at marciab@caltech.edu.