Miller Harry J D, Anders Janet
Department of Physics and Astronomy, University of Exeter, Stocker Road, Exeter EX4 4QL, UK.
Entropy (Basel). 2018 Mar 16;20(3):200. doi: 10.3390/e20030200.
The Leggett-Garg inequalities serve to test whether or not quantum correlations in time can be explained within a classical macrorealistic framework. We apply this test to thermodynamics and derive a set of Leggett-Garg inequalities for the statistics of fluctuating work done on a quantum system unitarily driven in time. It is shown that these inequalities can be violated in a driven two-level system, thereby demonstrating that there exists no general macrorealistic description of quantum work. These violations are shown to emerge within the standard Two-Projective-Measurement scheme as well as for alternative definitions of fluctuating work that are based on weak measurement. Our results elucidate the influences of temporal correlations on work extraction in the quantum regime and highlight a key difference between quantum and classical thermodynamics.
莱格特-加尔格不等式用于检验时间上的量子关联是否能在经典宏观实在论框架内得到解释。我们将此检验应用于热力学，并针对在时间上被幺正驱动的量子系统上所做的涨落功的统计量，推导出一组莱格特-加尔格不等式。结果表明，在一个受驱动的两能级系统中这些不等式可能被违背，从而证明不存在对量子功的一般宏观实在论描述。这些违背情况在标准的双投影测量方案中以及基于弱测量的涨落功的替代定义下都有所体现。我们的结果阐明了时间关联对量子 regime 中功提取的影响，并突出了量子热力学与经典热力学之间的一个关键差异。
