Concentric transmon qubit featuring fast tunability and site-selective Z coupling

ORAL

Abstract

We present a planar qubit design based on a superconducting circuit that we call concentric transmon. While employing a simple fabrication process using Al evaporation and lift-off lithography, we observe qubit lifetimes and coherence times in the order of 10 $\mu$s. We systematically characterize loss channels such as incoherent dielectric loss, Purcell decay and radiative losses. The implementation of a gradiometric SQUID loop allows for a fast tuning of the qubit transition frequency and therefore for full tomographic control of the quantum circuit. The presented qubit design features a passive direct Z coupling between neighboring qubits, being a pending quest in the field of quantum simulation.

Authors

  • Martin Weides

    • Karlsruhe Institute of Technology
  • Jochen Braumueller

    • Karlsruhe Institute of Technology
  • Martin Sandberg

    • National Institute of Standards and Technology
  • Michael Vissers

    • National Institute of Standards and Technology
  • Andre Schneider

    • Karlsruhe Institute of Technology
  • Steffen Schloer

    • Karlsruhe Institute of Technology
  • Lukas Gruenhaupt

    • Karlsruhe Institute of Technology
  • Hannes Rotzinger

    • Karlsruhe Institute of Technology
  • Michael Marthaler

    • Karlsruhe Institute of Technology
  • Alexander Lukashenko

    • Karlsruhe Institute of Technology
  • Amadeus Dieter

    • Karlsruhe Institute of Technology
  • Alexey Ustinov

    • Karlsruhe Institute of Technology
  • David Pappas

    • National Institute of Standards and Technology