Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Cryogenic microwave loss in epitaxial Al/GaAs/Al trilayers for superconducting circuits



Corey Rae McRae, A. McFadden, Ruichen Zhao, Haozhi Wang, Junling Long, Tongyu Zhao, Sungoh Park, Mustafa Bal, Christopher J. Palmstrom, David P. Pappas


Epitaxially grown superconductor/dielectric/superconductor trilayers have the potential to form high-performance superconducting quantum devices and may even allow scalable superconducting quantum computing with low-surface-area qubits such as the merged-element transmon. In this work, we measure the power-independent loss and two-level-state (TLS) loss of epitaxial, wafer-bonded, and substrate-removed Al/GaAs/Al trilayers by measuring lumped element superconducting microwave resonators at millikelvin temperatures and down to single-photon powers. The power-independent loss of the device is (4.8±0.1)×10−5, and the resonator-induced intrinsic TLS loss is (6.4±0.2)×10−5. Dielectric loss extraction is used to determine a lower bound of the intrinsic TLS loss of the trilayer of 7.2×10−5. The unusually high power-independent loss is attributed to GaAs's intrinsic piezoelectricity.
Journal of Applied Physics


McRae, C. , McFadden, A. , Zhao, R. , Wang, H. , Long, J. , Zhao, T. , Park, S. , Bal, M. , Palmstrom, C. and Pappas, D. (2021), Cryogenic microwave loss in epitaxial Al/GaAs/Al trilayers for superconducting circuits, Journal of Applied Physics, [online], (Accessed April 19, 2024)
Created January 14, 2021, Updated April 25, 2023