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Updated: Aug 5, 2026

Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators
Published on: May 30, 2014
Planckian Bound on Quantum Dynamical Entropy
1Université Paris Cité, Sorbonne Université, CNRS, Université PSL, Laboratoire de Physique de l'École normale supérieure, ENS, F-75005 Paris, France.
Abstract:
We introduce a simplified version of Connes-Narnhofer-Thirring's quantum dynamical entropy for quantum systems. It quantifies the amount of information gained about the initial condition from continuously monitoring an observable. A nonzero entropy growth rate can be obtained by monitoring the thermal fluctuation of an extensive observable in a generic many-body system, away from classical or large N limits. We explicitly compute the entropy rate in the thermodynamic and long-time limit in terms of the two-point correlation functions. We conjecture a universal Planckian bound for the entropy rate. Related results on the purification rate are also obtained.
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