Magnetic imaging of superconducting qubit devices with scanning SQUID-on-tip

Authors :: Marchiori, E.
Ceccarelli, L.
Rossi, N.
Romagnoli, G.
Herrmann, J.
Besse, J. -C.
Krinner, S.
Wallraff, A.
Poggio, M.
Source :: Appl. Phys. Lett. 121, 052601 (2022)
Publication Year :: 2022
Abstract: We use a scanning superconducting quantum interference device (SQUID) to image the magnetic flux produced by a superconducting device designed for quantum computing. The nanometer-scale SQUID-on-tip probe reveals the flow of superconducting current through the circuit as well as the locations of trapped magnetic flux. In particular, maps of current flowing out of a flux-control line in the vicinity of a qubit show how these elements are coupled, providing insight on how to optimize qubit control.<br />Comment: 5 pages, 3 figures