Practical Characterization and Control of Quantum Systems

Christopher Granade1, 2, joint work with Christopher Ferrie3, Nathan Wiebe4, Ian Hincks1, 5, Troy Borneman1, and D. G. Cory1,6,7

Primarily based on arXiv:1207.1655, arXiv:1404.5275, and on forthcoming work.

Presented 24 June, 2014 as a seminar at Sandia National Laboratories.

Slides: HTML IPython Notebook: download, view online

Abstract

High-fidelity control of quantum systems is an essential component in the development of useful quantum information processing devices. Such control is predicated on a characterization of the system of interest, and the accuracy of control is then assessed through characterization. In this seminar, we discuss novel approaches for each, and show how our work addresses practical concerns in quantum information experiments.

In particular, we address the characterization of quantum devices by applying the sequential Monte Carlo (SMC) algorithm. This algorithm is shown to be robust, including to finite sampling and to errors in simulation. We demonstrate the practicality of our approach by showing examples in randomized benchmarking experiments and in learning properties of nitrogen vacancy centers.

We also show how models of electronic systems can be incorporated into optimal control algorithms such as gradient-ascent pulse engineering (GRAPE). Our work allows accurate control to be obtained, even in the presence of strongly non-linear control systems.

Our work thus provides methods for the characterization and control of quantum systems that address practical concerns in modern quantum information experiments.

Software Resources

QInfer, a Python-language implementation of the classical portions of the algorithms presented in this work, is available from GitHub.

Bibliography

View on Zotero

Affiliations

  1. Institute for Quantum Computing, University of Waterloo.
  2. Department of Physics, University of Waterloo.
  3. Center for Quantum Information and Control, University of New Mexico.
  4. Microsoft Research.
  5. Department of Applied Mathematics, University of Waterloo.
  6. Department of Chemistry, University of Waterloo.
  7. Perimeter Institute for Theoretical Physics.