Studies of decoherence in a large area Nb flux qubit

ORAL

Abstract

We report measurements using pulsed microwaves to investigate the decoherence mechanisms in a large area Nb based flux qubit. Our qubit uses an rf-SQUID in a gradiometer configuration and has independent, in situ, controls for the relative positions of levels in different fluxoid wells and the barrier height between the wells. We present measurements of decoherence times from coherent oscillations and microwave spectroscopy. These measurements are well suited to evaluate potential improvements in the materials and the fabrication process of both flux and phase qubits based on different flux states.

*This work is supported in part by AFOSR and NSA through a DURINT program and by NSF.

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Authors

  • Douglas Bennett

    • Stony Brook University, Department of Physics and Astronomy

  • Luigi Longobardi

    • Stony Brook University, Department of Physics and Astronomy

  • Vijay Patel

    • Stony Brook University, Department of Physics and Astronomy

  • Wei Chen

    • Stony Brook University, Department of Physics and Astronomy

  • Dmitri Averin

    • Stony Brook University, Department of Physics and Astronomy

  • Antonio Di Lorenzo

    • Stony Brook University, Department of Physics and Astronomy

  • Vladimir Kuznetsov

    • Stony Brook University, Department of Physics and Astronomy

  • Jaan Mannik

    • Stony Brook University, Department of Physics and Astronomy

  • Shawn Pottorf

    • Stony Brook University, Department of Physics and Astronomy

  • Kristian Rabenstein

    • Stony Brook University, Department of Physics and Astronomy

  • James Lukens

    • Stony Brook University, Department of Physics and Astronomy