Finite-time quantum Otto engine: Surpassing the quasistatic efficiency due to friction.

Area of Science:

• Quantum Thermodynamics
• Finite-Time Quantum Heat Engines
• Quantum Statistical Mechanics

Background:

• Finite-time quantum heat engines consume work to overcome coherence-related friction in the working fluid.
• Understanding friction's role is crucial for optimizing quantum thermodynamic cycles.
• Quantum Otto cycles serve as a fundamental model for studying heat engine performance.

Purpose of the Study:

• To investigate the impact of friction on finite-time quantum Otto cycles.
• To compare the performance of quantum Otto cycles using Agarwal and Lindbladian baths.
• To analyze the behavior of quantum heat engines in both quasistatic and short-time limits.

Main Methods:

• Exact analytical solutions for finite-time quantum Otto cycles with Agarwal and Lindbladian baths.
• Comparison of engine performance metrics, including efficiency and power output.
• Numerical calculations to support analytical findings and explore underlying mechanisms.

Main Results:

• The Agarwal engine exhibits significantly higher performance due to friction, exceeding quasistatic Otto efficiency.
• The Lindbladian engine demonstrates non-zero power output even in the short-time limit.
• Distinct performance characteristics arise from the different bath models (Agarwal vs. Lindbladian).

Conclusions:

• Friction in finite-time quantum heat engines can lead to counterintuitive performance enhancements.
• Nonequilibrium working fluids can achieve superior performance compared to equilibrium fluids, even with equilibrium baths.
• The choice of bath model critically influences the dynamics and performance of quantum heat engines.