Density Matrix Exponentiation on a Superconducting Quantum Processor (Part 2): Demonstration and Characterization

ORAL

Abstract

Density matrix exponentiation (DME) represents a unique style of quantum operation, in which many copies of a quantum state ρ are used to perform a unitary operation U(ρ, θ) = eiρθ on a second quantum system σ. Traditionally, changing an operation on σ requires changing a sequence of classically-defined gates; in DME, a fixed gate sequence performs a range of operations simply by varying the quantum input. DME is a Trotter-style algorithm, in which the total angle of rotation θ is built up by performing N rotations of θ/N with algorithmic error θ2/N. In Part 2 of this talk, we benchmark an implementation of the DME algorithm in a two-qubit system. We characterize U(ρ, θ) via process tomography, and demonstrate that the unitary depends on the input quantum state. We also explore tradeoffs between algorithmic error at small N and noise/loss limits at large N.

*This research was funded in part by the ARO grant No. W911NF-18-1-0411 and by the Assistant Secretary of Defense for Research & Engineering via MIT Lincoln Laboratory under Air Force Contract No. FA8721-05-C-0002. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the U.S. Government.

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Presenters

  • Mollie Schwartz

    • MIT Lincoln Laboratory
    • MIT Lincoln Lab

Authors

  • Mollie Schwartz

    • MIT Lincoln Laboratory
    • MIT Lincoln Lab

  • Morten Kjaergaard

    • Research Laboratory of Electronics, Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology MIT
    • Research Laboratory of Electronics, Massachusetts Institute of Technology
    • Massachusetts Institute of Technology

  • Amy Greene

    • Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology
    • Research Laboratory of Electronics, Massachusetts Institute of Technology

  • Gabriel Orr Samach

    • MIT Research Laboratory of Electronics, MIT Department of Electrical Engineering and Computer Science, MIT Lincoln Laboratory, Massachusetts Institute of Technology
    • MIT Lincoln Laboratory, Massachusetts Institute of Technology
    • Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology
    • Research Laboratory of Electronics, Massachusetts Institute of Technology
    • MIT Lincoln Laboratory

  • Andreas Bengtsson

    • Research Laboratory of Electronics, Massachusetts Institute of Technology MIT
    • Chalmers University of Technology
    • Chalmers Univ of Tech
    • Chalmers Institute of Technology
    • Microtechnology and Nanoscience, Chalmers University of Technology

  • Michael O'Keeffe

    • MIT Lincoln Laboratory

  • Chris McNally

    • Massachusetts Institute of Technology
    • Massachusetts Institute of Technology MIT
    • Research Laboratory of Electronics, Massachusetts Institute of Technology

  • Youngkyu Sung

    • Research Laboratory of Electronics, Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology MIT
    • Research Laboratory of Electronics, Massachusetts Institute of Technology
    • Massachusetts Institute of Technology

  • Milad Marvian

    • Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology

  • Philip Krantz

    • Research Laboratory of Electronics, Massachusetts Institute of Technology MIT
    • Chalmers University of Technology
    • Chalmers Institute of Technology
    • Chalmers Univ of Tech

  • Jochen Braumueller

    • Massachusetts Institute of Technology MIT
    • Research Laboratory of Electronics, Massachusetts Institute of Technology
    • Massachusetts Institute of Technology

  • Roni Winik

    • Research Laboratory of Electronics, Massachusetts Institute of Technology
    • Research Laboratory of Electronics, Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology

  • 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

  • Alexander Melville

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

  • Bethany Niedzielski

    • MIT Lincoln Laboratory

  • Jonilyn Yoder

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

  • Danna Rosenberg

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

  • Kevin Obenland

    • MIT Lincoln Laboratory

  • Terry Philip Orlando

    • Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology
    • Research Laboratory of Electronics, Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology MIT
    • Electrical Engineering and Computer Science, Massachusetts Institute of Technology
    • Research Laboratory of Electronics, Massachusetts Institute of Technology
    • Massachusetts Institute of Technology
    • MIT Lincoln Laboratory
    • Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology (MIT)

  • Iman Marvian

    • Duke
    • Duke University

  • Simon Gustavsson

    • Research Laboratory of Electronics, Massachusetts Institute of Technology
    • Research Laboratory of Electronics, Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology
    • Research Laboratory of Electronics, Massachusetts Institute of Technology (MIT)

  • Seth Lloyd

    • Massachusetts Institute of Technology
    • Massachusetts Institute of Technology MIT
    • MIT
    • Mechanical Engineering, Massachusetts Institute of Technology

  • William Oliver

    • Research Laboratory of Electronics, Department of Electrical Engineering and Computer Science, Department of Physics, MIT Lincoln Laboratory, Massachusetts Institute of Techn
    • MIT Lincoln Lab
    • MIT Lincoln Laboratory
    • MIT Lincoln Laboratory, Massachusetts Institute of Technology
    • Department of Physics, Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Lincoln Laboratory, Massachusetts Institute of Technology
    • Research Laboratory of Electronics, Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology MIT
    • Department of Electrical Engineering and Computer Science, Department of Physics, Massachusetts Institute of Technology; MIT Lincoln Laboratory
    • Department of Electrical Engineering and Computer Science, Department of Physics, MIT Lincoln Laboratory, Massachusetts Institute of Technology
    • Massachusetts Institute of Technology
    • Research Laboratory of Electronics, Massachusetts Institute of Technology
    • Research Laboratory of Electronics, Department of Electrical Engineering & Computer Science, Department of Physics, Massachusetts Institute of Technology and MIT Lincoln Labo
    • Physics, MIT
    • MIT-Lincoln Lab
    • MIT Lincoln Laboratories
    • Research Laboratory of Electronics, Department of Physics, Department of Electrical Engineering and Computer Science, Lincoln Laboratory, Massachusetts Institute of Technolog