We consider the quality factor $\mathcal{Q}$, 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, in both classical and quantum mechanics, sets the bound $\mathcal{Q}=3/8$ when approaching the Carnot efficiency. On the other hand, interacting, nonintegrable, and momentum-conserving systems can achieve the value $\mathcal{Q}=1/2$, 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.

中文翻译：

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稳态热力发动机的功率，效率和波动

我们考虑质量因素 $\mathcal{问}$，它量化了动态系统建模的稳态热机的功率，效率和波动之间的权衡。我们证明了非线性散射理论在经典力学和量子力学中都设定了界$\mathcal{问}=3/8$达到卡诺效率时。另一方面，相互作用的，不可集成的和动量守恒的系统可以实现价值$\mathcal{问}=\mathrm{1个}/2$，这是线性响应的通用上限。该结果表明相互作用是实现稳态热力发动机最佳性能所必需的。