Coherent dynamics of collective modes in the fluxonium qubit

ORAL

Abstract

When biased at the sweet spot, the fluxonium qubit outperforms any other superconducting qubit regarding the relaxation time T1. This performance is related to the implementation of a superinductor made of a Josephson junction chain. We have fabricated and measured a 3D fluxonium qubit. The relaxation time peaks at half flux quantum at about T1=450$\mu$s. In the standard fluxonium circuit one can neglect the electromagnetic modes of the Josephson junction chain because their frequency is much higher than the qubit frequency. We present on-going results on the design of a fluxonium qubit where the frequencies of these electromagnetic modes is in the order of the qubit frequency. We expect coherent dynamics between the qubit and the collective modes.

Authors

  • Farshad Foroughi

    • CNRS, Institut Néel, F-38000 Grenoble, France
  • Etienne Dumur

    • University of Chicago, United states
  • Doriane Drolet

    • University of Sherbrooke, Sherbrooke, Canada
  • Yuriy Krupko

    • CNRS, Institut Néel, F-38000 Grenoble, France
  • Remy Dassonneville

    • CNRS, Institut Néel, F-38000 Grenoble, France
  • Luca Planat

    • CNRS, Institut Néel, F-38000 Grenoble, France
  • Javier Puertas-Martinez

    • CNRS, Institut Néel, F-38000 Grenoble, France
  • Cecile Naud

    • CNRS, Institut Néel, F-38000 Grenoble, France
  • Olivier Buisson

    • CNRS, Institut Néel, F-38000 Grenoble, France
  • Nicola Roch

    • CNRS, Institut Néel, F-38000 Grenoble, France
  • Ioan Pop

    • Karlsruhe Institute of Technology, Karlsruhe, Germany
  • Wiebke Guichard

    • CNRS, Institut Néel, F-38000 Grenoble, France