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An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
Stochastic thermodynamics, fluctuation theorems and molecular machines
1II. Institut für Theoretische Physik, Universität Stuttgart, 70550 Stuttgart, Germany.
Reports on Progress in Physics. Physical Society (Great Britain)
|November 22, 2012
Summary
Stochastic thermodynamics extends classical concepts like heat and entropy to individual non-equilibrium processes. This framework, applied to molecular machines and devices, reveals new insights into energy flow and efficiency.
Area of Science:
- Physics
- Physical Chemistry
- Statistical Mechanics
Background:
- Classical thermodynamics traditionally applies to macroscopic systems in equilibrium.
- Extending thermodynamic concepts to microscopic, non-equilibrium systems is a significant challenge.
- Individual trajectories of small systems exhibit fluctuations not captured by classical theories.
Purpose of the Study:
- To systematically review the framework of stochastic thermodynamics.
- To extend classical thermodynamic notions (work, heat, entropy production) to individual trajectories of non-equilibrium ensembles.
- To unify various fluctuation theorems and explore their applications.
Main Methods:
- Applying stochastic thermodynamics to paradigmatic systems like colloidal particles, polymers, molecular motors, and thermoelectric devices.
- Utilizing Langevin equations for continuum dynamics and master equations for discrete states.
- Deriving fluctuation theorems from a master theorem for constrained probability distributions.
- Analyzing non-equilibrium steady states and employing cycle decomposition for efficiency analysis.
Main Results:
- A first-law-like energy balance is identified along fluctuating trajectories.
- Thermodynamic consistency imposes local-detailed balance constraints.
- Integral and detailed fluctuation theorems constrain probability distributions of thermodynamic quantities.
- Generalized fluctuation-dissipation theorems and insights into irreversibility are established.
- Efficiency at maximum power is analyzed beyond linear response for molecular machines.
Conclusions:
- Stochastic thermodynamics provides a unified framework for analyzing non-equilibrium processes at the single-trajectory level.
- The framework offers powerful tools for understanding energy transduction and efficiency in small systems.
- Applications range from optimal control to feedback mechanisms and the fundamental nature of irreversibility.
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