Long range coupling through a chain of RF-SQUIDs for superconducting flux qubit quantum annealers

ORAL

Abstract

Increasing the degree of coupling in a quantum annealer can improve its computational power; however, each physical connection to a superconducting flux qubit increases its area and hence its susceptibility to noise. The coupler tree architecture is a proposed solution which allows increasing coupling degree without increasing qubit area. We report on a subgraph of the coupler tree consisting of 2 capacitively shunted flux qubits connected by 7 RF-SQUIDs. We experimentally demonstrate propagation of a magnetic flux signal through the chain, visible as a frequency step in the persistent current readouts attached to each qubit and coupler. Anticrossing spectroscopy is explored to confirm the quantum character of the coupling. Results are in agreement with full quantum circuit simulations. Prospects for measurement of entanglement and noise are discussed.

*This material is based upon work supported by the Intelligence Advanced Research Projects Activity (IARPA) and the Army Research Office (ARO) under Contract No. W911NF-17-C-0050. Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the Intelligence Advanced Research Projects Activity (IARPA) and the Army Research Office (ARO).

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Presenters

  • Antonio Javier Martinez

    • University of Waterloo

Authors

  • Antonio Javier Martinez

    • University of Waterloo

  • Daniel M Tennant

    • University of Waterloo

  • Xi Dai

    • University of Waterloo

  • Denis Melanson

    • University of Waterloo

  • Ali Yurtalan

    • University of Waterloo

  • Salil Bedkihal

    • University of Waterloo

  • Edward Tang

    • University of Waterloo

  • Alexander Melville

    • MIT Lincoln Laboratory
    • MIT Lincoln Lab
    • MIT Lincoln Laboratories
    • Massachusetts Institute of Technology (MIT) Lincoln Laboratory

  • Bethany M Niedzielski

    • MIT Lincoln Laboratory

  • Rabindra Das

    • MIT Lincoln Laboratory
    • MIT Lincoln Laboratories

  • David K Kim

    • MIT Lincoln Laboratory
    • MIT Lincoln Lab
    • MIT-Lincoln Lab
    • MIT Lincoln Laboratories
    • Lincoln Laboratory, Massachusetts Institute of Technology (MIT)
    • Massachusetts Institute of Technology (MIT) Lincoln Laboratory

  • Jonilyn Yoder

    • MIT Lincoln Laboratory
    • MIT-Lincoln Lab
    • Lincoln Laboratory, Massachusetts Institute of Technology (MIT)
    • MIT Lincoln Lab

  • Steven Weber

    • MIT Lincoln Laboratory

  • Andrew James Kerman

    • MIT Lincoln Laboratory

  • Sergey Novikov

    • Northrop Grumman
    • Northrop Grumman - Mission Systems
    • Northrop Grumman Corporation

  • Steven M Disseler

    • Northrop Grumman
    • Northrop Grumman - Mission Systems
    • Northrop Grumman Corporation

  • James I Basham

    • Northrop Grumman
    • Northrop Grumman - Mission Systems
    • Northrop Grumman Corporation

  • Jeffrey Grover

    • Northrop Grumman
    • Northrop Grumman - Mission Systems
    • Northrop Grumman Corporation

  • Evgeny Mozgunov

    • University of Southern California
    • Viterbi school of engineering, University of Southern California

  • Daniel A Lidar

    • University of Southern California
    • Univ of Southern California
    • 5. University of Southern California, Los Angeles, California 90089, USA

  • Adrian Lupascu

    • University of Waterloo