The European Physical Journal Special Topics

, Volume 227, Issue 3–4, pp 365–378 | Cite as

Reducing backaction when measuring temporal correlations in quantum systems

  • Michael KastnerEmail author
  • Philipp Uhrich
Regular Article
Part of the following topical collections:
  1. Quantum Systems In and Out of Equilibrium - Fundamentals, Dynamics and Applications


Dynamic correlations of quantum observables are challenging to measure due to measurement backaction incurred at early times. Recent work [P. Uhrich et al., Phys. Rev. A 96, 022127 (2017)] has shown that ancilla-based noninvasive measurements are able to reduce this backaction, allowing for dynamic correlations of single-site spin observables to be measured. We generalise this result to correlations of arbitrary spin observables and extend the measurement protocol to simultaneous noninvasive measurements which allow for real and imaginary parts of correlations to be extracted from a single set of measurements. We use positive operator-valued measures to analyse the dynamics generated by the ancilla-based measurements. Using this framework we prove that special observables exist for which measurement backaction is of no concern, so that dynamic correlations of these can be obtained without making use of ancillas.


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  1. 1.
    P. Uhrich, S. Castrignano, H. Uys, M. Kastner, Phys. Rev. A 96, 022127 (2017) ADSCrossRefGoogle Scholar
  2. 2.
    B. Yan, S.A. Moses, B. Gadway, J.P. Covey, K.R.A. Hazzard, A.M. Rey, D.S. Jin, J. Ye, Nature 501, 521 (2013) ADSCrossRefGoogle Scholar
  3. 3.
    A. Schwarzkopf, R.E. Sapiro, G. Raithel, Phys. Rev. Lett. 107, 103001 (2011) ADSCrossRefGoogle Scholar
  4. 4.
    T. Lahaye, C. Menotti, L. Santos, M. Lewenstein, T. Pfau, Rep. Prog. Phys. 72, 126401 (2009) ADSCrossRefGoogle Scholar
  5. 5.
    J.W. Britton, B.C. Sawyer, A.C. Keith, C.-C.J. Wang, J.K. Freericks, H. Uys, M.J. Biercuk, J. J. Bollinger, Nature 484, 489 (2012) ADSCrossRefGoogle Scholar
  6. 6.
    R. Ozeri, Contemp. Phys. 52, 531 (2011) ADSCrossRefGoogle Scholar
  7. 7.
    J. Zeiher, R. van Bijnen, P. Schausz, S. Hild, J. Choi, T. Pohl, I. Bloch, C. Gross, Nat. Phys. 12, 1095 (2016) CrossRefGoogle Scholar
  8. 8.
    W.S. Bakr, J.I. Gillen, A. Peng, S. Fölling, M. Greiner, Nature 462, 74 (2009) ADSCrossRefGoogle Scholar
  9. 9.
    J. Zhang, G. Pagano, P.W. Hess, A. Kyprianidis, P. Becker, H. Kaplan, A.V. Gorshkov, Z.-X. Gong, C. Monroe, Nature 551, 601 (2017) ADSCrossRefGoogle Scholar
  10. 10.
    K. Jacobs, Quantum Measurement Theory and its Applications (Cambridge University Press, Cambridge, 2014) Google Scholar
  11. 11.
    M.A. Nielsen, I.L. Chuang, Quantum Computation and Quantum Information (Cambridge University Press, Cambridge, 2000) Google Scholar
  12. 12.
    A. Peres, Quantum Theory: Concepts and Methods (Kluwer Academic Publishers, USA, 1993) Google Scholar
  13. 13.
    A. Steane, Appl. Phys. B 64, 623 (1997) ADSCrossRefGoogle Scholar
  14. 14.
    D.F.V. James, Appl. Phys. B 66, 181 (1997) ADSCrossRefGoogle Scholar
  15. 15.
    J. Home, Quantum Science and Metrology with Mixed-Species Ion Chains, in Advances In Atomic, Molecular, and Optical Physics (Elsevier, Amsterdam, 2013), Vol. 62, p. 231 Google Scholar
  16. 16.
    J. Wright, C. Auchter, C.-K. Chou, R.D. Graham, T.W. Noel, T. Sakrejda, Z. Zhou, B.B. Blinov, Quantum Inf. Process. 15, 5339 (2016) ADSCrossRefGoogle Scholar

Copyright information

© EDP Sciences and Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.National Institute for Theoretical Physics (NITheP)StellenboschSouth Africa
  2. 2.Institute of Theoretical Physics, Department of Physics, University of StellenboschStellenboschSouth Africa

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