Light-matter interactions in realistic settings: unifying open quantum systems with macroscopic quantum electrodynamics

“光与孤立物质（即单原子）之间的相互作用已经研究了几十年。这是很容易理解的，但在现实中，没有一个系统可以真正地与可能高度复杂的环境隔离开来。这个困难导致了各种各样的技术来处理所谓的开放量子系统，在开放量子系统中，要研究的“系统”和与之相互作用的“环境”是有区别的。一个相关但独立的形式称为宏观量子电动力学（MQED）旨在描述量子光与耗散介质的相互作用。它的优势在于考虑了非均匀物体，比如那些需要计算复杂物体之间卡西米尔力的物体。MQED中描述的系统与开放量子系统中讨论的系统类似，但是MQED的哲学和基础完全不同。例如，它不区分给定设置的“系统”和“环境”部分。在这个博士项目中要回答的问题是，MQED的形式化能否与开放量子系统的形式化统一。由此产生的理论将具有广泛的适用性；一个最初的例子是不均匀环境中振动活跃分子之间能量传递的集体效应。”

"The interaction between light and isolated matter (i.e. single atoms) has been studied for decades. It is well understood, but in reality, no system can be truly isolated from its surroundings which may be highly complex. This difficulty has led to various techniques for dealing with what are known as open quantum systems, where a distinction is made between a 'system' to be studied and an 'environment' with which it interacts.A related but separate formalism called macroscopic quantum electrodynamics (MQED) aims to describe the interaction of quantum light with dissipative media. Its strengths are in taking into account inhomogeneous objects, such as those needed to calculate Casimir forces between complex objects. The systems described in MQED are similar to those discussed in open quantum systems, but the philosophy and underpinnings of MQED are entirely different. For example, it makes no distinction between the 'system' and 'environment' parts of a given setup. The question to be answered during this PhD project whether the formalism of MQED can be unified with that of open quantum systems. The resulting theory would have broad applicability; one initial example would be collective effects in energy transfer between vibrationally-active molecules in inhomogeneous environments. "