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Published on: May 30, 2014
Fluctuations of work from quantum subensembles: the case against quantum work-fluctuation theorems
A E Allahverdyan1, Th M Nieuwenhuizen
1Institute for Theoretical Physics, Valckenierstraat 65, 1018 XE Amsterdam, The Netherlands.
Summary
This study explores how the second law of thermodynamics emerges in quantum systems by averaging work fluctuations. It introduces a novel definition of work consistent with energy conservation in non-equilibrium quantum states.
Area of Science:
- Quantum Thermodynamics
- Statistical Mechanics
- Quantum Optics
Background:
- The second law of thermodynamics traditionally states no work from cyclic processes in equilibrium.
- Understanding its quantum analogue requires analyzing work fluctuations.
Purpose of the Study:
- To investigate the emergence of the second law in quantum systems.
- To define and analyze fluctuations of work for quantum ensembles.
- To reconcile quantum work definitions with classical thermodynamics.
Main Methods:
- Splitting mixed quantum ensembles into pure subensembles via measurement filtering.
- Defining work as energy exchanged with macroscopic sources.
- Comparing the approach with quantum optics experiments.
Main Results:
- A novel definition of quantum work consistent with energy conservation.
- The definition applies to non-equilibrium quantum states.
- No direct generalization of the classical work-fluctuation theorem to quantum systems exists.
Conclusions:
- The emergence of the second law in quantum mechanics involves non-classical scenarios.
- A new framework for understanding work and fluctuations in quantum thermodynamics is presented.
- This work offers a consistent definition of work for quantum ensembles.
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