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  • Letter
  • Open Access

Quantum dynamical entropy and dissipative information flows

Giovanni Nichele1,2,3,* and Fabio Benatti2,3

  • *Contact author: gnichele@umk.pl
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APS Open Sci. 1, L000196 – Published 2 November, 2026

DOI: https://doi.org/10.1103/6hlj-9t5r

Abstract

The Alicki-Lindblad-Fannes (ALF) dynamical entropy measures the rate at which new information is gathered about a quantum system by inspecting its long-time evolution. After extending the ALF entropy to open quantum dynamics, we propose it as a measure of backflow of information from the environment. We show that the behavior of the open-system ALF entropy is a stronger witness than existing approaches based only on the open-system reduced dynamics. In the case of a qubit collisionally coupled to a classical spin chain, we obtain an exact expression for the open-system ALF entropy explicitly depending on the environment correlations. An extreme case shows how the information flow from environment to system corresponds to vanishing entropy production as for reversible finite quantum systems.

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Quantum dynamical entropy and non-Markovianity: A collisional model perspective

Giovanni Nichele and Fabio Benatti
Phys. Rev. A 114, 052406 (2026)

Article Text

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APS Open Sci. 1, L000196– Published 2 November, 2026
Vol. 1
  • Received 14 March 2026
  • Accepted 7 October 2026
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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.

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