论文标题
波动的量子热
Fluctuating quantum heat
论文作者
论文摘要
进行投射能量测量的量子系统平均能量的增加称为“量子热”，这总是零。在量子随机热力学的框架中，这被构造为波动量子热（FQH）的平均值，定义为沿两点本本特征轨迹的哈密顿量的预期值增加。但是，这样的定义有两个缺点：（i）如果初始状态不与哈密顿式通勤并具有归化性，则FQH的较高时刻将不会被唯一地定义，因此，这种数量是否具有物理有意义是可以说的； （ii）该定义在操作上是要求的，因为它需要完全了解初始状态。在当前的手稿中，我们表明FQH是顺序测量的能量有条件增加的一个实例，第一个是相对于初始状态的特征分类。通过粗糙粒度，首先仅通过区分状态的退化子空间，最后不区分任何子空间，我们为FQH提供了两个替代定义，我们将其称为部分粗粒的FQH和完全粗粒的FQH。部分粗粒的FQH解决了问题（i），而完全粗粒的FQH则可以解决（i）和（ii）。
The increase in average energy of a quantum system undergoing projective energy measurements is referred to as "quantum heat", which is always zero. In the framework of quantum stochastic thermodynamics, this is constructed as the average over the fluctuating quantum heat (FQH), defined as the increase in expected value of the Hamiltonian along two-point eigenstate trajectories. However, such a definition has two drawbacks: (i) if the initial state does not commute with the Hamiltonian and has degeneracies, the higher moments of the FQH will not be uniquely defined, and therefore it is arguable whether such a quantity is physically meaningful; (ii) the definition is operationally demanding as it requires full knowledge of the initial state. In the present manuscript we show that the FQH is an instance of conditional increase in energy given sequential measurements, the first of which is with respect to the eigen-decomposition of the initial state. By coarse-graining this initial measurement, first by only distinguishing between degenerate subspaces of the state, and finally by not distinguishing between any subspace at all, we provide two alternative definitions for the FQH, which we call the partially coarse-grained FQH and fully coarse-grained FQH, respectively. The partially coarse-grained FQH resolves issue (i), whereas the fully coarse-grained FQH resolves both (i) and (ii).
