Planckian Bound on Quantum Dynamical Entropy
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.
Fields of Study & Subjects
Advanced Thermodynamics and Statistical Mechanics
Quantum Information and Cryptography
Statistical Mechanics and Entropy
Publication details
- Journal / source
- Physical Review Letters
- Publisher
- American Physical Society (APS)
- Volume
- 137
- Issue
- 3
- Pages
- 030402–030402
- Publication date
- 26 May 2026
- Language
- EN