Excited state population of a 3D transmon in thermal equilibrium

ORAL

Abstract

We present a systematic study of the excited state population of a 3D transmon qubit at various temperatures. We experimentally demonstrate that the population of the first excited state follows the Maxwell-Boltzmann distribution in the temperature range of 35-150 mK. For bath temperatures below 35 mK, the excited-state population saturates, with an upper-bound estimate of 0.1\%. The saturation suggests a qubit effective temperature of approximately 35 mK. The Lincoln Laboratory portion of this work was sponsored by the Assistant Secretary of Defense for Research \& Engineering under Air Force Contract number FA8721-05-C-0002. Opinions, interpretations, conclusions and recommendations are those of the author and are not necessarily endorsed by the United States Government.

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Authors

  • Xiaoyue Jin

    • Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
    • Research Laboratory of Electronics, Massachusetts Institute of Technology

  • S. Gustavsson

    • Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139

  • A. Kamal

    • Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139

  • A.P. Sears

    • MIT Lincoln Laboratory, 244 Wood Street, Lexington, Massachusetts 02420

  • T. Gudmundsen

    • MIT Lincoln Laboratory, 244 Wood Street, Lexington, Massachusetts 02420

  • D. Hover

    • MIT Lincoln Laboratory, 244 Wood Street, Lexington, Massachusetts 02420

  • A.J. Kerman

    • MIT Lincoln Laboratory, 244 Wood Street, Lexington, Massachusetts 02420

  • F. Yan

    • Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139

  • J. Yoder

    • MIT Lincoln Laboratory, 244 Wood Street, Lexington, Massachusetts 02420

  • T.P. Orlando

    • Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139

  • W.D. Oliver

    • Research Laboratory of Electronics, Massachusetts Institute of Technology, MIT Lincoln Laboratory, 244 Wood Street, Lexington, Massachusetts 02420