Hybrid Superconducting Circuit Devices for Sensing Quantum Materials

To study quantum materials and topological excitations, superconducting quantum circuits are natural platforms capitalizing the precise probe and control of microwaves with the tools of circuit quantum electrodynamics (cQED). In addition, hybrid superconducting circuit devices could have gate tunability and noise protection from the novel properties of topological materials. A transmon-like qubit with superconductor-topological insulator-superconductor (S-TI-S) junction has been designed, fabricated, and incorporated into a 3D copper cavity. Coherent transport properties of the TI material at the single quantum level could be revealed by the spectroscopic and time-domain measurements of the 3D TI-transmon qubit. We will also discuss other efforts to develop superconducting circuits and qubit-based sensors for probing quantum materials, materials defects, and other excitations.