Observation of Piezoelectricity at the Metal-Sapphire Interface

ORAL

Abstract

Interface piezoelectricity is a recently discovered superconducting qubit loss mechanism where symmetry breaking at a superconductor-silicon junction leads to piezoelectric transduction and phonon radiation [1]. Sapphire, another widely used qubit substrate, exhibits a non-piezoelectric bulk property and possesses a larger bandgap than silicon. In this talk, we present observations of piezoelectric response at the metal-sapphire interface probed using surface acoustic waves launched and detected via interdigital transducers. We quantify the strength of the interface piezoelectric effect, discuss possible microscopic origins, and model its impact on qubit coherence on sapphire substrates.

[1] H. Zhou et al., arXiv:2409.10626 (2024)

*This research was primarily supported by DOE under Contract No. DE-AC02-05-CH11231 and by the NSF Graduate Research Fellowship Program.

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Presenters

  • Kangdi Yu

    • University of California, Berkeley
    • UC Berkeley

Authors

  • Kangdi Yu

    • University of California, Berkeley
    • UC Berkeley

  • Haoxin Zhou

    • University of California, Berkeley and Lawrence Berkeley National Laboratory
    • University of California, Berkeley

  • John W Garmon

    • Yale University

  • Zihuai Zhang

    • University of California, Berkeley and Lawrence Berkeley National Laboratory
    • University of California, Berkeley

  • Robert J Schoelkopf

    • Yale University

  • Alp Sipahigil

    • University of California Berkeley
    • University of California, Berkeley
    • University of California, Berkeley and Lawrence Berkeley National Laboratory