Phase qubits fabricated with trilayer junctions

M. Weides; R. C. Bialczak; M. Lenander; E. Lucero; Matteo Mariantoni; M. Neeley; A. D. O'Connell; D. Sank; H. Wang; J. Wenner; T. Yamamoto; Y. Yin; A. N. Cleland; J. Martinis

doi:10.1088/0953-2048/24/5/055005

arXiv · 1101.0232

Phase qubits fabricated with trilayer junctions

M. Weides·R. C. Bialczak·M. Lenander·E. Lucero·Matteo Mariantoni·M. Neeley·A. D. O'Connell·D. Sank·H. Wang·J. Wenner·T. Yamamoto·Y. Yin·A. N. Cleland·J. Martinis

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Abstract

We have developed a novel Josephson junction geometry with minimal volume of lossy isolation dielectric, being suitable for higher quality trilayer junctions implemented in qubits. The junctions are based on in-situ deposited trilayers with thermal tunnel oxide, have micron-sized areas and a low subgap current. In qubit spectroscopy only a few avoided level crossings are observed, and the measured relaxation time of $T_1\approx400\;\rm{nsec}$ is in good agreement with the usual phase qubit decay time, indicating low loss due to the additional isolation dielectric.

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M. Weides, R. C. Bialczak, M. Lenander, E. Lucero, Matteo Mariantoni, M. Neeley, A. D. O'Connell, D. Sank, H. Wang, J. Wenner, T. Yamamoto, Y. Yin, A. N. Cleland, J. Martinis. 2010-12-31. Phase qubits fabricated with trilayer junctions. https://doi.org/10.1088/0953-2048/24/5/055005

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