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Variations on a demonic theme: Szilard's other engines.
Kyle J Ray1, James P Crutchfield1
1Complexity Sciences Center and Physics Department, University of California at Davis, One Shields Avenue, Davis, California 95616, USA.
Chaos (Woodbury, N.Y.)
|October 2, 2020
Summary
We analyzed Szilard's demon models, revealing the second is equivalent to single-molecule engines. Its function as an information engine is governed by statistical complexity and thermodynamic bounds.
Area of Science:
- Thermodynamics
- Statistical Mechanics
- Information Theory
Background:
- Leon Szilard proposed three models in 1929 to address Maxwell's demon paradox.
- The first model, a single-molecule engine, has been extensively analyzed.
- This study focuses on Szilard's two remaining demon models.
Purpose of the Study:
- To analyze Szilard's second and third demon models.
- To investigate the informational and thermodynamic equivalence of Szilard's second model.
- To explore the relationship between entropy production, measurement, and information engines.
Main Methods:
- Analysis of Szilard's second demon model, involving distinct molecular species and semipermeable membranes.
- Characterization of the second model as a chaotic dynamical system (Szilard Map).
- Investigation of the third model concerning entropy production and measurement tasks.
Main Results:
- The second model is informationally and thermodynamically equivalent to an ideal gas of single-molecule engines.
- The functioning of the second model is governed by the Kolmogorov-Sinai entropy rate.
- The demon's optimal functioning depends on statistical complexity, saturating thermodynamic bounds.
- The third model addresses the link between entropy production and measurement.
Conclusions:
- Szilard's second model is a minimal, optimal implementation of an information engine.
- The analysis provides insights for designing nanoscale information engines.
- Understanding the interplay of memory, working fluid, and thermodynamic costs is crucial for novel engine designs.
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