Performance of a quantum heat engine at strong reservoir coupling

Area of Science:

• Quantum thermodynamics
• Statistical mechanics
• Condensed matter physics

Background:

• Investigating quantum heat engines is crucial for understanding energy conversion at the quantum level.
• Previous studies were limited to weak system-reservoir coupling, neglecting important correlations.
• Strong coupling is relevant for nanoscale devices and quantum information processing.

Purpose of the Study:

• To develop a theoretical framework for analyzing quantum heat engines at strong coupling.
• To incorporate system-reservoir correlations into thermodynamic analysis.
• To evaluate the performance of a quantum Otto cycle under strong coupling conditions.

Main Methods:

• Utilized a collective coordinate mapping to include system-reservoir correlations.
• Developed a consistent thermodynamic analysis for strongly coupled quantum systems.
• Applied the formalism to a quantum Otto cycle model.

Main Results:

• Strong coupling significantly reduces the work output and energy conversion efficiency of the quantum Otto cycle.
• Sudden decoupling between the system and reservoirs incurs performance costs.
• An alternative operational procedure was proposed to partially restore performance.

Conclusions:

• The collective coordinate mapping provides a powerful tool for studying quantum thermodynamics beyond weak coupling.
• Strong coupling effects must be considered for accurate predictions of quantum heat engine performance.
• The developed formalism opens avenues for broader investigations into quantum thermodynamic systems.