标题： 从可逆量子微观动力学到不可逆量子输运 显示英文标题

标题： From Reversible Quantum Microdynamics to Irreversible Quantum Transport

摘要： 借助所谓的投影方法可以非常有效地研究从可逆微观动力学到不可逆输运的转变。 我们对该方法进行了简洁的介绍，通过用它来分析著名的速率方程和量子玻尔兹曼方程来展示其强大功能，并且作为新的应用，给出了一个描述强场中电子-正电子对自发产生的源项的推导。 在此过程中，我们强调了时间尺度的重要性：只有当动力学表现出的各种时间尺度存在显著差异时，较慢自由度的演化才能由传统的马尔可夫输运方程来描述；否则，必须考虑有限记忆效应。 我们展示了如何使用投影方法来确定这些时间尺度，以及如果需要的话，如何以直接的方式包括记忆效应。 最后，附录部分讨论了熵和宏观不可逆性的概念。 显示英文摘要

摘要： The transition from reversible microdynamics to irreversible transport can be studied very efficiently with the help of the so-called projection method. We give a concise introduction to that method, illustrate its power by using it to analyze the well-known rate and quantum Boltzmann equations, and present, as a new application, the derivation of a source term accounting for the spontaneous creation of electron-positron pairs in strong fields. Thereby we emphasize the fundamental importance of time scales: only if the various time scales exhibited by the dynamics are widely disparate, can the evolution of the slower degrees of freedom be described by a conventional Markovian transport equation; otherwise, one must account for finite memory effects. We show how the projection method can be employed to determine these time scales, and how --if necessary-- it allows one to include memory effects in a straightforward manner. Finally, there is an appendix in which we discuss the concepts of entropy and macroscopic irreversibility.