论文标题
量子相干性和麦角
Quantum Coherence and Ergotropy
论文作者
论文摘要
工作提取的限制是我们对经典和量子系统热力学的运营理解的基础。在量子设置中，有限的时间控制操作通常会在动态系统的瞬时能量本质上产生连贯性。原则上可以设计热力学周期，以从这种非平衡资源中提取工作。在这里，我们在此类方案中隔离并研究量子相干成分与工作产率。具体而言，我们确定了对麦角拷贝的相干贡献（通过哈密顿参数的周期性变化，单位提取的工作的最大量）。我们通过将最佳转换分为不一致的操作和相干提取周期来显示这一点。我们获得了可提取工作的相干和不连贯部分的边界，并在特定设置中讨论了它们的饱和度。我们的结果用几个示例进行了说明，包括有限维系统和玻色症高斯状态，这些状态描述了具有量化载荷的量子热发动机的最新实验。
Constraints on work extraction are fundamental to our operational understanding of the thermodynamics of both classical and quantum systems. In the quantum setting, finite-time control operations typically generate coherence in the instantaneous energy eigenbasis of the dynamical system. Thermodynamic cycles can, in principle, be designed to extract work from this non-equilibrium resource. Here, we isolate and study the quantum coherent component to the work yield in such protocols. Specifically, we identify a coherent contribution to the ergotropy (the maximum amount of unitarily extractable work via cyclical variation of Hamiltonian parameters). We show this by dividing the optimal transformation into an incoherent operation and a coherence extraction cycle. We obtain bounds for both the coherent and incoherent parts of the extractable work and discuss their saturation in specific settings. Our results are illustrated with several examples, including finite-dimensional systems and bosonic Gaussian states that describe recent experiments on quantum heat engines with a quantized load.
