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Fluctuations in irreversible quantum Otto engines.

Guangqian Jiao1, Shoubao Zhu1, Jizhou He1

  • 1Department of Physics, Nanchang University, Nanchang 330031, China.

Physical Review. E
|April 17, 2021
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Summary
This summary is machine-generated.

This study analyzes stochastic work in quantum Otto engines, revealing how finite-time operations impact efficiency and work fluctuations. It provides a framework for understanding irreversible quantum thermodynamics.

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Area of Science:

  • Quantum Thermodynamics
  • Statistical Mechanics
  • Quantum Information

Background:

  • Quantum Otto engines are theoretical models for quantum heat engines.
  • Irreversibility in thermodynamic cycles arises from finite-time operations.
  • Stochastic thermodynamics studies fluctuations in small systems.

Purpose of the Study:

  • To derive the probability distribution function for stochastic work in quantum Otto engines.
  • To investigate the effects of irreversibility due to finite cycle duration.
  • To analyze work fluctuations, average work, and thermodynamic efficiency.

Main Methods:

  • Derivation of the general probability distribution function for stochastic work.
  • Analysis of an analytically solvable two-level quantum system.
  • Explicit calculation of time-dependent work fluctuations and average work.

Main Results:

  • The general probability distribution of stochastic work was derived for irreversible quantum Otto engines.
  • Time-dependent work fluctuations, average work, and efficiency were explicitly obtained.
  • The impact of finite-time irreversibility on efficiency and fluctuations was quantified.

Conclusions:

  • Finite-time operations introduce irreversibility, significantly affecting quantum Otto engine performance.
  • Work fluctuations and relative power fluctuations are sensitive to cycle time.
  • The study provides a theoretical foundation for designing more efficient quantum heat engines.