Spectators Errors in Multiqubit Tunable Coupling Architectures

ORAL

Abstract

The addition of tunable couplers to superconducting quantum architectures offers significant advantages for scalability compared to fixed coupling approaches. Couplers such as the one proposed in Ref. [1] allow exact cancellation of qubit-qubit coupling by interfering the coupling through a capacitor with the coupling through a tunable qubit. However, the cancellation is necessarily narrowband, and in a multiqubit environment with stray couplings the cancellation condition can change depending on which gate is operating and even the states of the qubits. Here we investigate a modified version Ref. [1] coupler in multiqubit environment. With near-detuned qubits, we find that stray coupling can induce gate errors of order 1% when performing simultaneous gates if the microwave crosstalk is not carefully engineered.
[1] F. Yan et al. Phys. Rev. Applied. 10, 054063 (2018)

Presenters

  • David Zajac

    • IBM TJ Watson Research Center
    • IBM Quantum

Authors

  • David Zajac

    • IBM TJ Watson Research Center
    • IBM Quantum
  • Jiri Stehlik

    • IBM TJ Watson Research Center
    • IBM Quantum
  • Devin Underwood

    • IBM TJ Watson Research Center
    • IBM Quantum
  • Timothy Phung

    • IBM TJ Watson Research Center
    • IBM Quantum
  • Muir Kumph

    • IBM TJ Watson Research Center
    • IBM Quantum
  • John Blair

    • IBM TJ Watson Research Center
    • IBM Corporation
  • Santino Carnevale

    • IBM Quantum, IBM T. J. Watson Research Center, Yorktown Heights, NY 10598, USA
    • IBM TJ Watson Research Center
    • IBM Quantum
  • Dave Klaus

    • IBM TJ Watson Research Center
    • IBM Quantum
  • April Carniol

    • IBM TJ Watson Research Center
    • IBM Quantum, Yorktown Heights NY 10598
  • George Keefe

    • IBM TJ Watson Research Center
    • IBM Quantum
  • Matthias Steffen

    • IBM Quantum, IBM T. J. Watson Research Center, Yorktown Heights, NY 10598, USA
    • IBM TJ Watson Research Center
  • Oliver E. Dial

    • IBM TJ Watson Research Center
    • IBM Quantum
    • Massachusetts Institute of Technology MIT