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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.

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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