Experimental Estimation of Average Fidelity of a Clifford Gate on a 7-Qubit Quantum Processor

Dawei Lu, Hang Li, Denis-Alexandre Trottier, Jun Li, Aharon Brodutch, Anthony P. Krismanich, Ahmad Ghavami, Gary I. Dmitrienko, Guilu Long, Jonathan Baugh, and Raymond Laflamme
Phys. Rev. Lett. 114, 140505 – Published 8 April 2015
PDFHTMLExport Citation

Abstract

One of the major experimental achievements in the past decades is the ability to control quantum systems to high levels of precision. To quantify the level of control we need to characterize the dynamical evolution. Full characterization via quantum process tomography is impractical and often unnecessary. For most practical purposes, it is enough to estimate more general quantities such as the average fidelity. Here we use a unitary 2-design and twirling protocol for efficiently estimating the average fidelity of Clifford gates, to certify a 7-qubit entangling gate in a nuclear magnetic resonance quantum processor. Compared with more than 108 experiments required by full process tomography, we conducted 1656 experiments to satisfy a statistical confidence level of 99%. The average fidelity of this Clifford gate in experiment is 55.1%, and rises to at least 87.5% if the signal’s decay due to decoherence is taken into account. The entire protocol of certifying Clifford gates is efficient and scalable, and can easily be extended to any general quantum information processor with minor modifications.

  • Figure
  • Figure
  • Received 28 November 2014

DOI:https://doi.org/10.1103/PhysRevLett.114.140505

© 2015 American Physical Society

Authors & Affiliations

Dawei Lu1, Hang Li1,2,3, Denis-Alexandre Trottier1, Jun Li1,4, Aharon Brodutch1, Anthony P. Krismanich5, Ahmad Ghavami5, Gary I. Dmitrienko5, Guilu Long2,3, Jonathan Baugh1,5, and Raymond Laflamme1,6,7,*

  • 1Institute for Quantum Computing and Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
  • 2State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
  • 3Collaborative Innovation Center of Quantum Matter, Beijing 100084, China
  • 4Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
  • 5Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
  • 6Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5, Canada
  • 7Canadian Institute for Advanced Research, Toronto, Ontario M5G 1Z8, Canada

  • *laflamme@iqc.ca

Article Text (Subscription Required)

Click to Expand

Supplemental Material (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 114, Iss. 14 — 10 April 2015

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review Letters

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×