Finite-time thermodynamic process of a two-level quantum heat engine

TL;DR

This paper analyzes a two-level quantum heat engine operating in finite time, deriving explicit thermodynamic quantities and showing the efficiency at maximum power aligns with universal theoretical predictions.

Contribution

It provides explicit analytic expressions for thermodynamic quantities in a finite-time two-level quantum heat engine, including maximum power and efficiency.

Findings

Efficiency at maximum power matches universal first-order Carnot efficiency.

Derived explicit formulas for work, heat, and power in finite-time quantum processes.

Validated theoretical predictions with analytic results.

Abstract

In this paper, we consider a model of two-level quantum heat engine to investigate the explicit analytic expression for the thermodynamics quantities in different condition under the finite-time operation. In this engine, the working substance is composed of a spin-half particles immersed in a magnetic field. The finite-time thermodynamic processes consisting of two quantum adiabatic and two quantum isothermal processes. This processes working between two heat reservoirs with an inverse temperatures $\beta_{1}$ and $\beta_{2}$ ($<\beta_{1}$). In this processes, we obtain the work, heat, power and efficiency at maximum power output of the model. Our result of the efficiency at maximum power agree with the universal value in the first order of Carnot efficiency.