标题： 量子相变中的相干与耗散动力学 显示英文标题

标题： Coherent and dissipative dynamics at quantum phase transitions

摘要： 量子相变中的多体物理表现出量子涨落和热涨落之间微妙的相互作用，在低温极限下显现出来。 在这篇综述中，我们首先对这一背景下系统的平衡行为给出了教学性的介绍，其标度框架本质上是通过利用量子-经典映射以及连续相变临界现象的重正化群理论发展起来的。 然后我们专注于涉及非平衡量子动力学的协议，例如瞬时淬火和缓慢穿过量子跃迁的过程。 这些大多是在动态标度框架内讨论的，该框架是通过对平衡标度定律进行适当的扩展而获得的。 我们也回顾了关于一阶量子跃迁的现象，其独特的标度行为特征是对边界条件的极端敏感性，导致相同本征系统的指数或幂律行为。 在最后一部分，我们涵盖了与环境耗散相互作用效应相关的方面，通过量子跃迁动态标度的适当推广来实现这一点。 我们的阐述局限于由封闭的多体系统开发的量子跃迁所涉及的问题，并受其控制，将耗散视为临界区域的微扰，就像零温量子跃迁中的温度一样。 我们关注的是导致临界模式与各种耗散机制之间非平凡相互作用的物理条件，通常当所涉及的机制仅激发量子跃迁的低能模式时才会实现。 显示英文摘要

摘要： The many-body physics at quantum phase transitions shows a subtle interplay between quantum and thermal fluctuations, emerging in the low-temperature limit. In this review, we first give a pedagogical introduction to the equilibrium behavior of systems in that context, whose scaling framework is essentially developed by exploiting the quantum-to-classical mapping and the renormalization-group theory of critical phenomena at continuous phase transitions. Then we specialize to protocols entailing the out-of-equilibrium quantum dynamics, such as instantaneous quenches and slow passages across quantum transitions. These are mostly discussed within dynamic scaling frameworks, obtained by appropriately extending the equilibrium scaling laws. We review phenomena at first-order quantum transitions as well, whose peculiar scaling behaviors are characterized by an extreme sensitivity to the boundary conditions, giving rise to exponentials or power laws for the same bulk system. In the last part, we cover aspects related to the effects of dissipative interactions with an environment, through suitable generalizations of the dynamic scaling at quantum transitions. The presentation is limited to issues related to, and controlled by, the quantum transition developed by closed many-body systems, treating the dissipation as a perturbation of the critical regimes, as for the temperature at the zero-temperature quantum transition. We focus on the physical conditions giving rise to a nontrivial interplay between critical modes and various dissipative mechanisms, generally realized when the involved mechanism excites only the low-energy modes of the quantum transitions.