论文标题

完整计数统计和相干:使用统一量子主方程的热传输中的波动对称性

Full counting statistics and coherences: fluctuation symmetry in heat transport with the Unified quantum master equation

论文作者

Gerry, Matthew, Segal, Dvira

论文摘要

最近,得出了一个“统一”的量子主方程,并显示为Gorini-Kossakowski-Lindblad-Sudarshan(GKLS)形式。该方程式描述了开放量子系统的动力学,以放弃整个世俗近似值并保留特征能量近距离之间的连贯性的影响。我们使用统一量子主方程实施完整的计数统计数据,以通过几乎退化水平的开放量子系统来研究能量电流的统计数据。我们表明,通常,该方程式产生了满足波动对称性的动力学,这是平均通量水平下热力学第二定律的足够条件。对于具有近乎退化的能级的系统,因此相干构建,统一方程在热力学上同时是一致的,并且比完全世俗的主方程更准确。我们为“ V”系统的结果举例说明了我们在不同温度下两个热浴之间促进能量传输的结果。我们将统一方程预测的稳态热电流的统计数据与Redfield方程给出的统计数据进行比较,而红场方程的统计数据较小,但通常在热力学上不一致。我们还将结果与世俗方程式进行了比较,后者完全放弃了连贯。我们发现,保持几乎退化水平之间的连贯性对于正确捕获电流及其累积物至关重要。另一方面,体现热力学不确定性关系的热电流的相对波动表现出对量子相干的无关紧要的依赖。

Recently, a "Unified" quantum master equation was derived and shown to be of the Gorini-Kossakowski-Lindblad-Sudarshan (GKLS) form. This equation describes the dynamics of open quantum systems in a manner that forgoes the full secular approximation and retains the impact of coherences between eigenstates close in energy. We implement full counting statistics with the Unified quantum master equation to investigate the statistics of energy currents through open quantum systems with nearly degenerate levels. We show that, in general, this equation gives rise to dynamics that satisfy fluctuation symmetry, a sufficient condition for the Second Law of Thermodynamics at the level of average fluxes. For systems with nearly degenerate energy levels, such that coherences build up, the Unified equation is simultaneously thermodynamically consistent and more accurate than the fully Secular master equation. We exemplify our results for a "V" system facilitating energy transport between two thermal baths at different temperatures. We compare the statistics of steady-state heat currents through this system as predicted by the Unified equation to those given by the Redfield equation, which is less approximate but, in general, not thermodynamically consistent. We also compare results to the Secular equation, where coherences are entirely abandoned. We find that maintaining coherences between nearly degenerate levels is essential for the properly capturing the current and its cumulants. On the other hand, the relative fluctuations of the heat current, which embody the thermodynamic uncertainty relation, display inconsequential dependence on quantum coherences.

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