Charging by thermalization.
Charging by thermalization.
复制标题
通过热化充电。
DOI：
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
A. Imparato
中科院分区：
文献类型：
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作者：
K. Hovhannisyan;F. Barra;A. Imparato
热系统的强耦合子系统通常将处于无热状态，并且在某些情况下，将有可能从这种状态中统一地提取功。同时，作为热平衡的一部分，子系统可以无限期地和免费地保持其状态。我们通过设计一个电池充电和存储单元来使用这些观察结果，该单元仅由一个热浴组成，并通过系统-浴耦合来发挥作用。充电循环包括将系统连接到浴槽，让它们热化，断开系统并从中提取功，需要很少的外部控制和微调。作为热力学第二定律的结果，我们表明，可以存储和提取的工作和总的工作花费在连接和断开系统-效率-之间的比率总是$\leq 1$，这是一个单一的浴类似的卡诺约束。此外，耦合，作为机器的资源，也是耗散的来源：每个充电周期的熵产生总是显着的，这强烈限制了所有耦合强度制度的效率。我们表明，我们的研究结果也适用于通用微正则浴。最后，我们说明了我们的理论上的Caldeira-Leggett模型与谐振子耦合到一个谐波浴。我们推导出一般的渐近公式在弱耦合和超强耦合制度，任意欧姆谱密度。此外，我们分析了模型的高温极限，显示，沿着的方式，即能量均分举行的势能和动能。最后，我们表明，可以通过将系统的几个副本连接到浴中来提高效率。
A strongly coupled subsystem of a thermal system will generally be in an athermal state, and in some cases, it will be possible to unitarily extract work from such a state. At the same time, being part of a thermal equilibrium, the subsystem can maintain its state indefinitely and for free. We put these observations to use by devising a battery charging and storing unit, made up of just a thermal bath and put in action by system-bath coupling. The charging cycle, consisting of connecting the system to the bath, letting them thermalize, disconnecting the system, and extracting work from it, requires very little external control and fine-tuning. As a consequence of the second law of thermodynamics, we show that the ratio between the work that can be stored and extracted and the total work spent on connecting and disconnecting the system---the efficiency---is always $\leq 1$, which is a single-bath analogue of the Carnot bound. Moreover, coupling, being a resource for the machine, is also a source of dissipation: the entropy production per charging cycle is always significant, which strongly limits the efficiency in all coupling strength regimes. We show that our results also hold for generic microcanonical baths. Finally, we illustrate our theory on the Caldeira-Leggett model with a harmonic oscillator coupled to a harmonic bath. We derive general asymptotic formulas in both weak and ultrastrong coupling regimes, for arbitrary Ohmic spectral densities. Also, we analyze the model in the high-temperature limit, showing, along the way, that energy equipartition holds both for potential and kinetic energies. Lastly, we show that the efficiency can be increased by connecting several copies of the system to the bath.
关于量子共振产生的不可逆动力学
DOI：
10.1063/1.4944614
发表时间：
2016
期刊：
arXiv: Mathematical Physics
影响因子：
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作者：
M. Könenberg;M. Merkli
通讯作者：
M. Merkli