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Power and efficiency of a thermal engine with a coherent bath
Thomas Guff1, Shakib Daryanoosh1, Ben Q Baragiola1
1Centre for Engineered Quantum Systems, Department of Physics and Astronomy, Macquarie University, Sydney NSW 2113, Australia.
Physical Review. E
|October 24, 2019
Summary
Quantum engines utilize ground-state coherence as a resource, enhancing power and efficiency by reducing thermalization temperature. Adjusting coherence optimizes engine performance.
Area of Science:
- Quantum thermodynamics
- Quantum optics
- Statistical mechanics
Background:
- Coherence in quantum systems can act as a thermodynamic resource.
- Previous work by Scully et al. established a quantum engine model using ground-state coherence.
- The quasistatic limit of such engines has been explored previously.
Purpose of the Study:
- To investigate a quantum engine model beyond the quasistatic limit.
- To explore the role of ground-state coherence in non-equilibrium quantum thermal cycles.
- To determine how coherence influences thermalization rate, power, and efficiency.
Main Methods:
- Modeling a quantum engine driven by weak interactions with a three-level atom heat bath.
- Analyzing the engine's performance out of the quasistatic limit.
- Investigating the relationship between ground-state coherence and thermalization dynamics.
Main Results:
- Ground-state coherence dictates the thermalization rate in the non-quasistatic regime.
- Increased coherence enhances output power and engine efficiency when thermalization temperature is reduced.
- Coherence acts as a resource that can be optimized alongside stroke durations for improved performance.
Conclusions:
- Ground-state coherence is a crucial resource for quantum engine operation, influencing both thermalization and performance.
- Optimizing coherence and stroke durations allows for enhanced quantum engine power and efficiency.
- The study reveals a nuanced role for coherence in quantum thermodynamics beyond equilibrium assumptions.
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