标题： 由压缩量子场引起的原子涨落量子辐射和反应 显示英文标题

标题： Fluctuations-Induced Quantum Radiation and Reaction from an Atom in a Squeezed Quantum Field

摘要： 在关于量子辐射的系列文章的第三部分中，我们探讨了利用量子场中保存的记忆来破译关于早期宇宙某些信息的可行性。 作为一项模型研究，我们让一个无质量的量子场在有限的时间间隔内经历一个参数过程，使得该场的模式频率从一个常数值过渡到另一个常数值。 这种配置模仿了一个静态受限的宇宙，而不是一个持续演化的宇宙。 通过这一过程压缩的场应包含该过程本身的的信息。 如果在参数过程之后将一个原子与该场耦合，其响应将取决于压缩情况，而原子发出的任何量子辐射都将携带这一信息，因此即使是在更晚时间的观察者也可能识别它。 我们的分析表明，1）远程观察者无法通过原子的辐射能量通量测量生成的压缩，因为净辐射能量通量被抵消了。 然而，2）在较晚的时间通过测量恒定的辐射能量密度有可能识别压缩。 唯一的限制是这种能量密度具有近场性质。 本文的第二部分关注3）压缩对参数过程功能形式的依赖性。 通过几个例子，我们证明了压缩的行为反映了参数过程的基本特性。 事实上，在涉及各种尺度的复杂过程中可能会出现显著的特征。 这些分析使我们能够建立压缩量子场的性质与执行压缩的参数过程之间的联系。 因此，4）可以构建模板，从受压缩的可测量量数据中重建未知的参数过程。 在后续论文中，这些结果将应用于宇宙学中的量子辐射研究。 显示英文摘要

摘要： In this third of a series on quantum radiation, we explore the feasibility of using the memories kept in a quantum field to decipher certain information about the early universe. As a model study, we let a massless quantum field be subjected to a parametric process for a finite time interval such that the mode frequency of the field transits from one constant value to another. This configuration mimics a statically-bounded universe, but not a continuously evolving one. The field squeezed by this process should contain information of the process itself. If an atom is coupled to the field after the parametric process, its response will depend on the squeezing, and any quantum radiation emitted by the atom will carry this information away so that an observer at a much later time may still identify it. Our analyses show that 1) a remote observer cannot measure the generated squeezing via the radiation energy flux from the atom because the net radiation energy flux is canceled. However, 2) there is a chance to identify squeezing by measuring the constant radiation energy density at late times. The only restriction is that this energy density is of the near-field nature. The second part of this paper focuses on 3) the dependence of squeezing on the functional form of the parametric process. Via several examples we demonstrate that the behavior of squeezing reflect essential properties of the parametric process. In fact, striking features may show up in complicated processes involving various scales. These analyses allow us to establish the connection between properties of a squeezed quantum field and the parametric process which does the squeezing. Therefore, 4) one can construct templates to reconstitute the unknown parametric processes from the data of measurable quantities subjected to squeezing. In a sequel paper these results will be applied to a study of quantum radiations in cosmology.