Power-efficiency-fluctuations trade-off in steady-state heat engines: The role of interactions

TL;DR

This paper investigates the fundamental limits of steady-state heat engines, revealing how interactions enable surpassing traditional bounds on power, efficiency, and fluctuations, and establishing the importance of interactions for optimal engine performance.

Contribution

It demonstrates that interactions are essential for achieving the upper bound of the quality factor in heat engines, surpassing classical and quantum scattering theory limits.

Findings

Nonlinear scattering theory bounds Q at 3/8 near Carnot efficiency.

Interacting, nonintegrable systems reach Q=1/2, the universal linear response limit.

Interactions are crucial for optimal steady-state heat engine performance.

Abstract

We consider the quality factor Q, which quantifies the trade-off between power, efficiency, and fluctuations in steady-state heat engines modeled by dynamical systems. We show that the nonlinear scattering theory, both in classical and quantum mechanics, sets the bound Q=3/8 when approaching the Carnot efficiency. On the other hand, interacting, nonintegrable and momentum-conserving systems can achieve the value Q=1/2, which is the universal upper bound in linear response. This result shows that interactions are necessary to achieve the optimal performance of a steady-state heat engine.