Quantum Otto Heat Engine based on the Dicke-Stark Model under Infinite-Time and Finite-Time Thermodynamic Frameworks

TL;DR

This paper introduces a quantum Otto heat engine utilizing a finite-size Dicke-Stark model, analyzing how system parameters influence its efficiency and power within different thermodynamic frameworks.

Contribution

It provides a detailed numerical analysis of the Dicke-Stark model as a working substance, exploring parameter effects on engine performance and proposing strategies for optimization.

Findings

Maximum work and efficiency occur near the superradiant phase transition.

Adjusting Stark field strength reduces entropy and quantum friction.

Asymmetric heat engine configurations improve performance.

Abstract

We propose a quantum Otto heat engine that employs a finite-size Dicke-Stark model as the working substance. In the extended coherent state space, the complete energy spectrum and eigenstates of this model are obtained through numerical calculations. Within the infinite-time and finite-time thermodynamics frameworks, we investigate the effects of the Stark field strength, coupling strength, adiabatic stroke time, isochoric stroke time, and number of atoms in the DS model on the heat engine's output work, efficiency, and power. The results show that the maximum values of the output work and efficiency appear near the coupling strength corresponding to the superradiant phase transition point. Regulating the Stark field strength can tune the energy level structure of the system and the superradiant phase transition, effectively reducing entropy generation and quantum friction during nonequilibrium evolution of the system's states and thereby significantly increasing the engine's output work, efficiency, and power. Asymmetric heat engines, where the two isochoric strokes have different Stark field strengths and stroke times, are more conducive to optimizing the heat engine's performance. Additionally, in the DS model, an increase in the number of atoms is also beneficial for increasing the heat engine's output work and efficiency. The results of this paper facilitate the design of high-performance quantum heat engines.