- Physical Review Journals
All JournalsPhysics Magazine

Physical Review Research

Reuse & Permissions

It is not necessary to obtain permission to reuse this article or its components as it is available under the terms of the Creative Commons Attribution 4.0 International license. This license permits unrestricted use, distribution, and reproduction in any medium, provided attribution to the author(s) and the published article's title, journal citation, and DOI are maintained. Please note that some figures may have been included with permission from other third parties. It is your responsibility to obtain the proper permission from the rights holder directly for these figures.

Export citation

Export citation

Choose format for download:

Download Citation
  • Letter
  • Open Access

Decoherence from universal tomographic measurements

Dorje C. Brody1,2,* and Rishindra Melanathuru2

  • *Contact author:
PDF

Phys. Rev. Research 8, L012042 – Published 23 February, 2026

DOI: https://doi.org/10.1103/19m2-bq8x

Abstract

The decoherence phenomenon arising from an environmental monitoring of the state of a quantum system, as opposed to monitoring of a preferred observable, is worked out in detail using two equivalent formulations, namely, repeated applications of universal tomographic measurements using positive operator-valued measures, and its continuous time unraveling from the Lindblad equation. The effect of decoherence is analyzed by studying the evolution of Stratonovich-Weyl quasiprobability distributions on the state space of the system. It is shown that decoherence makes an arbitrary-given quasiprobability distribution manifestly positive, thus modeling the emergence of classicality in some sense. The decoherence timescale, the minimum time that quasiprobability distributions of every initial state of the system become non-negative, is shown to decrease in Hilbert-space dimension, and hence larger quantum systems decohere faster.

View figure in article

Physics Subject Headings (PhySH)

Article Text

References (31)

  1. W. H. Zurek, Decoherence, einselection, and the quantum origins of the classical, Rev. Mod. Phys. 75, 715 (2003).
  2. M. Schlosshauer, Decoherence and the Quantum-to-Classical Transition (Springer, Berlin, 2007).
  3. E. Joos, H. D. Zeh, C. Kiefer, D. Giulini, J. Kupsch, and I.-O. Stamatescu, Decoherence and the Appearance of a Classical World in Quantum Theory, 2nd ed. (Springer, Berlin, 2003).
  4. K. Jacobs and D. A. Steck, A straightforward introduction to continuous quantum measurement, Contemp. Phys. 47, 279 (2006).
  5. P. Busch, P. Lahti, and P. Mittelstaedt, The Quantum Theory of Measurement, 2nd ed. (Springer, Berlin, 1996).
  6. D. C. Brody, E.-M. Graefe, and R. Melanathuru, Phase-space measurements, decoherence, and classicality, Phys. Rev. Lett. 134, 120201 (2025).
  7. D. C. Brody and L. P. Hughston, Universal quantum measurements, J. Phys.: Conf. Ser. 624, 012002 (2015).
  8. Z. Xu, Quantum-to-classical transition via single-shot generalized measurements, arXiv:2507.13174.
  9. D. F. V. James, P. G. Kwiat, W. J. Munro, and A. G. White, Measurement of qubits, Phys. Rev. A 64, 052312 (2001).
  10. Quantum State Estimation, Lecture Notes in Physics, Vol. 649, edited by M. G. A. Paris and J. Řeháček (Springer, Berlin, 2004).
  11. G. Chiribella, G. M. D’Ariano and M. F. Sacchi, Efficient use of quantum resources for optimal estimation of SU(N) pure states, Phys. Rev. A 70, 062105 (2004).
  12. E. Bagan, M. Baig, and R. Muñoz-Tapia, Quantum reverse-engineering and tomography of SU(N) systems, Phys. Rev. A 73, 032301 (2006).
  13. T. Durt, B. G. Englert, I. Bengtsson, and K. Życzkowski, On mutually unbiased bases, Int. J. Quantum Inf. 08, 535 (2010).
  14. G. Tóth, W. Wieczorek, D. Gross, R. Krischek, H. Weinfurter, and H. J. Briegel, Permutationally invariant quantum tomography, Phys. Rev. Lett. 105, 250403 (2010).
  15. D. C. Brody and L. P. Hughston, Geometric quantum mechanics, J. Geom. Phys. 38, 19 (2001).
  16. D. C. Brody, Information geometry of density matrices and state estimation, J. Phys. A 44, 252002 (2011).
  17. K. Nemoto, Generalized coherent states for SU(N) systems, J. Phys. A 33, 3493 (2000).
  18. F. T. Hioe, Gell-Mann dynamic symmetry for N-level quantum systems, Phys. Rev. A 32, 2824 (1985).
  19. W. Zhong, Z. Sun, J. Ma, X. Wang, and F. Nori, Fisher information under decoherence in Bloch representation, Phys. Rev. A 87, 022337 (2013).
  20. R. A. Bertlmann and P. Krammer, Bloch vectors for qudits, J. Phys. A 41, 235303 (2008).
  21. I. Bengtsson and K. Życzkowski, Geometry of Quantum States: An Introduction to Quantum Entanglement, 2nd ed. (Cambridge University Press, Cambridge, 2017).
  22. M. A. Nielsen and I. L. Chuang, Quantum Computation and Quantum Information (Cambridge University Press, Cambridge, 2010).
  23. G. W. Gibbons, Typical states and density matrices, J. Geom. Phys. 8, 147 (1992).
  24. F. A. Berezin, Covariant and contravariant symbols of operators, Math. USSR Izv. 6, 1117 (1972).
  25. G. S. Agarwal, Relation between atomic coherent-state representation, state multipoles, and generalized phase-space distributions, Phys. Rev. A 24, 2889 (1981).
  26. R. L. Stratonovich, On distributions in representation space, Sov. Phys. JETP 4, 891 (1957).
  27. T. Tilma, M. J. Everitt, J. H. Samson, W. J. Munro, and K. Nemoto, Wigner functions for arbitrary quantum systems, Phys. Rev. Lett. 117, 180401 (2016).
  28. J. E. Runeson and J. O. Richardson, Generalized spin mapping for quantum-classical dynamics, J. Chem. Phys. 155, 124105 (2021).
  29. K. Husimi, Some formal properties of the density matrix, Proc. Phys.: Math. Soc. Jpn. 22, 264 (1940).
  30. E. P. Wigner, On the quantum correction for thermodynamic equilibrium, Phys. Rev. 40, 749 (1932).
  31. E. C. G. Sudarshan, Equivalence of semiclassical and quantum mechanical descriptions of statistical light beams, Phys. Rev. Lett. 10, 277 (1963).

Outline

Information

Phys. Rev. Research 8, L012042– Published 23 February, 2026
  • Received 11 November 2025
  • Accepted 23 January 2026
Crossmark - Check for updates button
Creative Commons Logo

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

Published by the American Physical Society

Sign In to Your Journals Account

Filter

Filter

Article Lookup

Enter a citation